Eric Lee / smarc-fsl-linux-kernel

libata-eh.c 112 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 
/*
 *  libata-eh.c - libata error handling
 *
 *  Maintained by:  Tejun Heo <tj@kernel.org>
 *    		    Please ALWAYS copy linux-ide@vger.kernel.org
 *		    on emails.
 *
 *  Copyright 2006 Tejun Heo <htejun@gmail.com>
 *
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as
 *  published by the Free Software Foundation; either version 2, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
 *  USA.
 *
 *
 *  libata documentation is available via 'make {ps|pdf}docs',
 *  as Documentation/DocBook/libata.*
 *
 *  Hardware documentation available from http://www.t13.org/ and
 *  http://www.sata-io.org/
 *
 */

#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/export.h>
#include <linux/pci.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include "../scsi/scsi_transport_api.h"

#include <linux/libata.h>

#include <trace/events/libata.h>
#include "libata.h"

enum {
	/* speed down verdicts */
	ATA_EH_SPDN_NCQ_OFF		= (1 << 0),
	ATA_EH_SPDN_SPEED_DOWN		= (1 << 1),
	ATA_EH_SPDN_FALLBACK_TO_PIO	= (1 << 2),
	ATA_EH_SPDN_KEEP_ERRORS		= (1 << 3),

	/* error flags */
	ATA_EFLAG_IS_IO			= (1 << 0),
	ATA_EFLAG_DUBIOUS_XFER		= (1 << 1),
	ATA_EFLAG_OLD_ER                = (1 << 31),

	/* error categories */
	ATA_ECAT_NONE			= 0,
	ATA_ECAT_ATA_BUS		= 1,
	ATA_ECAT_TOUT_HSM		= 2,
	ATA_ECAT_UNK_DEV		= 3,
	ATA_ECAT_DUBIOUS_NONE		= 4,
	ATA_ECAT_DUBIOUS_ATA_BUS	= 5,
	ATA_ECAT_DUBIOUS_TOUT_HSM	= 6,
	ATA_ECAT_DUBIOUS_UNK_DEV	= 7,
	ATA_ECAT_NR			= 8,

	ATA_EH_CMD_DFL_TIMEOUT		=  5000,

	/* always put at least this amount of time between resets */
	ATA_EH_RESET_COOL_DOWN		=  5000,

	/* Waiting in ->prereset can never be reliable.  It's
	 * sometimes nice to wait there but it can't be depended upon;
	 * otherwise, we wouldn't be resetting.  Just give it enough
	 * time for most drives to spin up.
	 */
	ATA_EH_PRERESET_TIMEOUT		= 10000,
	ATA_EH_FASTDRAIN_INTERVAL	=  3000,

	ATA_EH_UA_TRIES			= 5,

	/* probe speed down parameters, see ata_eh_schedule_probe() */
	ATA_EH_PROBE_TRIAL_INTERVAL	= 60000,	/* 1 min */
	ATA_EH_PROBE_TRIALS		= 2,
};

/* The following table determines how we sequence resets.  Each entry
 * represents timeout for that try.  The first try can be soft or
 * hardreset.  All others are hardreset if available.  In most cases
 * the first reset w/ 10sec timeout should succeed.  Following entries
 * are mostly for error handling, hotplug and those outlier devices that
 * take an exceptionally long time to recover from reset.
 */
static const unsigned long ata_eh_reset_timeouts[] = {
	10000,	/* most drives spin up by 10sec */
	10000,	/* > 99% working drives spin up before 20sec */
	35000,	/* give > 30 secs of idleness for outlier devices */
	 5000,	/* and sweet one last chance */
	ULONG_MAX, /* > 1 min has elapsed, give up */
};

static const unsigned long ata_eh_identify_timeouts[] = {
	 5000,	/* covers > 99% of successes and not too boring on failures */
	10000,  /* combined time till here is enough even for media access */
	30000,	/* for true idiots */
	ULONG_MAX,
};

static const unsigned long ata_eh_flush_timeouts[] = {
	15000,	/* be generous with flush */
	15000,  /* ditto */
	30000,	/* and even more generous */
	ULONG_MAX,
};

static const unsigned long ata_eh_other_timeouts[] = {
	 5000,	/* same rationale as identify timeout */
	10000,	/* ditto */
	/* but no merciful 30sec for other commands, it just isn't worth it */
	ULONG_MAX,
};

struct ata_eh_cmd_timeout_ent {
	const u8		*commands;
	const unsigned long	*timeouts;
};

/* The following table determines timeouts to use for EH internal
 * commands.  Each table entry is a command class and matches the
 * commands the entry applies to and the timeout table to use.
 *
 * On the retry after a command timed out, the next timeout value from
 * the table is used.  If the table doesn't contain further entries,
 * the last value is used.
 *
 * ehc->cmd_timeout_idx keeps track of which timeout to use per
 * command class, so if SET_FEATURES times out on the first try, the
 * next try will use the second timeout value only for that class.
 */
#define CMDS(cmds...)	(const u8 []){ cmds, 0 }
static const struct ata_eh_cmd_timeout_ent
ata_eh_cmd_timeout_table[ATA_EH_CMD_TIMEOUT_TABLE_SIZE] = {
	{ .commands = CMDS(ATA_CMD_ID_ATA, ATA_CMD_ID_ATAPI),
	  .timeouts = ata_eh_identify_timeouts, },
	{ .commands = CMDS(ATA_CMD_READ_NATIVE_MAX, ATA_CMD_READ_NATIVE_MAX_EXT),
	  .timeouts = ata_eh_other_timeouts, },
	{ .commands = CMDS(ATA_CMD_SET_MAX, ATA_CMD_SET_MAX_EXT),
	  .timeouts = ata_eh_other_timeouts, },
	{ .commands = CMDS(ATA_CMD_SET_FEATURES),
	  .timeouts = ata_eh_other_timeouts, },
	{ .commands = CMDS(ATA_CMD_INIT_DEV_PARAMS),
	  .timeouts = ata_eh_other_timeouts, },
	{ .commands = CMDS(ATA_CMD_FLUSH, ATA_CMD_FLUSH_EXT),
	  .timeouts = ata_eh_flush_timeouts },
};
#undef CMDS

static void __ata_port_freeze(struct ata_port *ap);
#ifdef CONFIG_PM
static void ata_eh_handle_port_suspend(struct ata_port *ap);
static void ata_eh_handle_port_resume(struct ata_port *ap);
#else /* CONFIG_PM */
static void ata_eh_handle_port_suspend(struct ata_port *ap)
{ }

static void ata_eh_handle_port_resume(struct ata_port *ap)
{ }
#endif /* CONFIG_PM */

static void __ata_ehi_pushv_desc(struct ata_eh_info *ehi, const char *fmt,
				 va_list args)
{
	ehi->desc_len += vscnprintf(ehi->desc + ehi->desc_len,
				     ATA_EH_DESC_LEN - ehi->desc_len,
				     fmt, args);
}

/**
 *	__ata_ehi_push_desc - push error description without adding separator
 *	@ehi: target EHI
 *	@fmt: printf format string
 *
 *	Format string according to @fmt and append it to @ehi->desc.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
void __ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
{
	va_list args;

	va_start(args, fmt);
	__ata_ehi_pushv_desc(ehi, fmt, args);
	va_end(args);
}

/**
 *	ata_ehi_push_desc - push error description with separator
 *	@ehi: target EHI
 *	@fmt: printf format string
 *
 *	Format string according to @fmt and append it to @ehi->desc.
 *	If @ehi->desc is not empty, ", " is added in-between.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
void ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
{
	va_list args;

	if (ehi->desc_len)
		__ata_ehi_push_desc(ehi, ", ");

	va_start(args, fmt);
	__ata_ehi_pushv_desc(ehi, fmt, args);
	va_end(args);
}

/**
 *	ata_ehi_clear_desc - clean error description
 *	@ehi: target EHI
 *
 *	Clear @ehi->desc.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
void ata_ehi_clear_desc(struct ata_eh_info *ehi)
{
	ehi->desc[0] = '\0';
	ehi->desc_len = 0;
}

/**
 *	ata_port_desc - append port description
 *	@ap: target ATA port
 *	@fmt: printf format string
 *
 *	Format string according to @fmt and append it to port
 *	description.  If port description is not empty, " " is added
 *	in-between.  This function is to be used while initializing
 *	ata_host.  The description is printed on host registration.
 *
 *	LOCKING:
 *	None.
 */
void ata_port_desc(struct ata_port *ap, const char *fmt, ...)
{
	va_list args;

	WARN_ON(!(ap->pflags & ATA_PFLAG_INITIALIZING));

	if (ap->link.eh_info.desc_len)
		__ata_ehi_push_desc(&ap->link.eh_info, " ");

	va_start(args, fmt);
	__ata_ehi_pushv_desc(&ap->link.eh_info, fmt, args);
	va_end(args);
}

#ifdef CONFIG_PCI

/**
 *	ata_port_pbar_desc - append PCI BAR description
 *	@ap: target ATA port
 *	@bar: target PCI BAR
 *	@offset: offset into PCI BAR
 *	@name: name of the area
 *
 *	If @offset is negative, this function formats a string which
 *	contains the name, address, size and type of the BAR and
 *	appends it to the port description.  If @offset is zero or
 *	positive, only name and offsetted address is appended.
 *
 *	LOCKING:
 *	None.
 */
void ata_port_pbar_desc(struct ata_port *ap, int bar, ssize_t offset,
			const char *name)
{
	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
	char *type = "";
	unsigned long long start, len;

	if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
		type = "m";
	else if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
		type = "i";

	start = (unsigned long long)pci_resource_start(pdev, bar);
	len = (unsigned long long)pci_resource_len(pdev, bar);

	if (offset < 0)
		ata_port_desc(ap, "%s %s%llu@0x%llx", name, type, len, start);
	else
		ata_port_desc(ap, "%s 0x%llx", name,
				start + (unsigned long long)offset);
}

#endif /* CONFIG_PCI */

static int ata_lookup_timeout_table(u8 cmd)
{
	int i;

	for (i = 0; i < ATA_EH_CMD_TIMEOUT_TABLE_SIZE; i++) {
		const u8 *cur;

		for (cur = ata_eh_cmd_timeout_table[i].commands; *cur; cur++)
			if (*cur == cmd)
				return i;
	}

	return -1;
}

/**
 *	ata_internal_cmd_timeout - determine timeout for an internal command
 *	@dev: target device
 *	@cmd: internal command to be issued
 *
 *	Determine timeout for internal command @cmd for @dev.
 *
 *	LOCKING:
 *	EH context.
 *
 *	RETURNS:
 *	Determined timeout.
 */
unsigned long ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd)
{
	struct ata_eh_context *ehc = &dev->link->eh_context;
	int ent = ata_lookup_timeout_table(cmd);
	int idx;

	if (ent < 0)
		return ATA_EH_CMD_DFL_TIMEOUT;

	idx = ehc->cmd_timeout_idx[dev->devno][ent];
	return ata_eh_cmd_timeout_table[ent].timeouts[idx];
}

/**
 *	ata_internal_cmd_timed_out - notification for internal command timeout
 *	@dev: target device
 *	@cmd: internal command which timed out
 *
 *	Notify EH that internal command @cmd for @dev timed out.  This
 *	function should be called only for commands whose timeouts are
 *	determined using ata_internal_cmd_timeout().
 *
 *	LOCKING:
 *	EH context.
 */
void ata_internal_cmd_timed_out(struct ata_device *dev, u8 cmd)
{
	struct ata_eh_context *ehc = &dev->link->eh_context;
	int ent = ata_lookup_timeout_table(cmd);
	int idx;

	if (ent < 0)
		return;

	idx = ehc->cmd_timeout_idx[dev->devno][ent];
	if (ata_eh_cmd_timeout_table[ent].timeouts[idx + 1] != ULONG_MAX)
		ehc->cmd_timeout_idx[dev->devno][ent]++;
}

static void ata_ering_record(struct ata_ering *ering, unsigned int eflags,
			     unsigned int err_mask)
{
	struct ata_ering_entry *ent;

	WARN_ON(!err_mask);

	ering->cursor++;
	ering->cursor %= ATA_ERING_SIZE;

	ent = &ering->ring[ering->cursor];
	ent->eflags = eflags;
	ent->err_mask = err_mask;
	ent->timestamp = get_jiffies_64();
}

static struct ata_ering_entry *ata_ering_top(struct ata_ering *ering)
{
	struct ata_ering_entry *ent = &ering->ring[ering->cursor];

	if (ent->err_mask)
		return ent;
	return NULL;
}

int ata_ering_map(struct ata_ering *ering,
		  int (*map_fn)(struct ata_ering_entry *, void *),
		  void *arg)
{
	int idx, rc = 0;
	struct ata_ering_entry *ent;

	idx = ering->cursor;
	do {
		ent = &ering->ring[idx];
		if (!ent->err_mask)
			break;
		rc = map_fn(ent, arg);
		if (rc)
			break;
		idx = (idx - 1 + ATA_ERING_SIZE) % ATA_ERING_SIZE;
	} while (idx != ering->cursor);

	return rc;
}

static int ata_ering_clear_cb(struct ata_ering_entry *ent, void *void_arg)
{
	ent->eflags |= ATA_EFLAG_OLD_ER;
	return 0;
}

static void ata_ering_clear(struct ata_ering *ering)
{
	ata_ering_map(ering, ata_ering_clear_cb, NULL);
}

static unsigned int ata_eh_dev_action(struct ata_device *dev)
{
	struct ata_eh_context *ehc = &dev->link->eh_context;

	return ehc->i.action | ehc->i.dev_action[dev->devno];
}

static void ata_eh_clear_action(struct ata_link *link, struct ata_device *dev,
				struct ata_eh_info *ehi, unsigned int action)
{
	struct ata_device *tdev;

	if (!dev) {
		ehi->action &= ~action;
		ata_for_each_dev(tdev, link, ALL)
			ehi->dev_action[tdev->devno] &= ~action;
	} else {
		/* doesn't make sense for port-wide EH actions */
		WARN_ON(!(action & ATA_EH_PERDEV_MASK));

		/* break ehi->action into ehi->dev_action */
		if (ehi->action & action) {
			ata_for_each_dev(tdev, link, ALL)
				ehi->dev_action[tdev->devno] |=
					ehi->action & action;
			ehi->action &= ~action;
		}

		/* turn off the specified per-dev action */
		ehi->dev_action[dev->devno] &= ~action;
	}
}

/**
 *	ata_eh_acquire - acquire EH ownership
 *	@ap: ATA port to acquire EH ownership for
 *
 *	Acquire EH ownership for @ap.  This is the basic exclusion
 *	mechanism for ports sharing a host.  Only one port hanging off
 *	the same host can claim the ownership of EH.
 *
 *	LOCKING:
 *	EH context.
 */
void ata_eh_acquire(struct ata_port *ap)
{
	mutex_lock(&ap->host->eh_mutex);
	WARN_ON_ONCE(ap->host->eh_owner);
	ap->host->eh_owner = current;
}

/**
 *	ata_eh_release - release EH ownership
 *	@ap: ATA port to release EH ownership for
 *
 *	Release EH ownership for @ap if the caller.  The caller must
 *	have acquired EH ownership using ata_eh_acquire() previously.
 *
 *	LOCKING:
 *	EH context.
 */
void ata_eh_release(struct ata_port *ap)
{
	WARN_ON_ONCE(ap->host->eh_owner != current);
	ap->host->eh_owner = NULL;
	mutex_unlock(&ap->host->eh_mutex);
}

/**
 *	ata_scsi_timed_out - SCSI layer time out callback
 *	@cmd: timed out SCSI command
 *
 *	Handles SCSI layer timeout.  We race with normal completion of
 *	the qc for @cmd.  If the qc is already gone, we lose and let
 *	the scsi command finish (EH_HANDLED).  Otherwise, the qc has
 *	timed out and EH should be invoked.  Prevent ata_qc_complete()
 *	from finishing it by setting EH_SCHEDULED and return
 *	EH_NOT_HANDLED.
 *
 *	TODO: kill this function once old EH is gone.
 *
 *	LOCKING:
 *	Called from timer context
 *
 *	RETURNS:
 *	EH_HANDLED or EH_NOT_HANDLED
 */
enum blk_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
{
	struct Scsi_Host *host = cmd->device->host;
	struct ata_port *ap = ata_shost_to_port(host);
	unsigned long flags;
	struct ata_queued_cmd *qc;
	enum blk_eh_timer_return ret;

	DPRINTK("ENTER\n");

	if (ap->ops->error_handler) {
		ret = BLK_EH_NOT_HANDLED;
		goto out;
	}

	ret = BLK_EH_HANDLED;
	spin_lock_irqsave(ap->lock, flags);
	qc = ata_qc_from_tag(ap, ap->link.active_tag);
	if (qc) {
		WARN_ON(qc->scsicmd != cmd);
		qc->flags |= ATA_QCFLAG_EH_SCHEDULED;
		qc->err_mask |= AC_ERR_TIMEOUT;
		ret = BLK_EH_NOT_HANDLED;
	}
	spin_unlock_irqrestore(ap->lock, flags);

 out:
	DPRINTK("EXIT, ret=%d\n", ret);
	return ret;
}

static void ata_eh_unload(struct ata_port *ap)
{
	struct ata_link *link;
	struct ata_device *dev;
	unsigned long flags;

	/* Restore SControl IPM and SPD for the next driver and
	 * disable attached devices.
	 */
	ata_for_each_link(link, ap, PMP_FIRST) {
		sata_scr_write(link, SCR_CONTROL, link->saved_scontrol & 0xff0);
		ata_for_each_dev(dev, link, ALL)
			ata_dev_disable(dev);
	}

	/* freeze and set UNLOADED */
	spin_lock_irqsave(ap->lock, flags);

	ata_port_freeze(ap);			/* won't be thawed */
	ap->pflags &= ~ATA_PFLAG_EH_PENDING;	/* clear pending from freeze */
	ap->pflags |= ATA_PFLAG_UNLOADED;

	spin_unlock_irqrestore(ap->lock, flags);
}

/**
 *	ata_scsi_error - SCSI layer error handler callback
 *	@host: SCSI host on which error occurred
 *
 *	Handles SCSI-layer-thrown error events.
 *
 *	LOCKING:
 *	Inherited from SCSI layer (none, can sleep)
 *
 *	RETURNS:
 *	Zero.
 */
void ata_scsi_error(struct Scsi_Host *host)
{
	struct ata_port *ap = ata_shost_to_port(host);
	unsigned long flags;
	LIST_HEAD(eh_work_q);

	DPRINTK("ENTER\n");

	spin_lock_irqsave(host->host_lock, flags);
	list_splice_init(&host->eh_cmd_q, &eh_work_q);
	spin_unlock_irqrestore(host->host_lock, flags);

	ata_scsi_cmd_error_handler(host, ap, &eh_work_q);

	/* If we timed raced normal completion and there is nothing to
	   recover nr_timedout == 0 why exactly are we doing error recovery ? */
	ata_scsi_port_error_handler(host, ap);

	/* finish or retry handled scmd's and clean up */
	WARN_ON(!list_empty(&eh_work_q));

	DPRINTK("EXIT\n");
}

/**
 * ata_scsi_cmd_error_handler - error callback for a list of commands
 * @host:	scsi host containing the port
 * @ap:		ATA port within the host
 * @eh_work_q:	list of commands to process
 *
 * process the given list of commands and return those finished to the
 * ap->eh_done_q.  This function is the first part of the libata error
 * handler which processes a given list of failed commands.
 */
void ata_scsi_cmd_error_handler(struct Scsi_Host *host, struct ata_port *ap,
				struct list_head *eh_work_q)
{
	int i;
	unsigned long flags;

	/* make sure sff pio task is not running */
	ata_sff_flush_pio_task(ap);

	/* synchronize with host lock and sort out timeouts */

	/* For new EH, all qcs are finished in one of three ways -
	 * normal completion, error completion, and SCSI timeout.
	 * Both completions can race against SCSI timeout.  When normal
	 * completion wins, the qc never reaches EH.  When error
	 * completion wins, the qc has ATA_QCFLAG_FAILED set.
	 *
	 * When SCSI timeout wins, things are a bit more complex.
	 * Normal or error completion can occur after the timeout but
	 * before this point.  In such cases, both types of
	 * completions are honored.  A scmd is determined to have
	 * timed out iff its associated qc is active and not failed.
	 */
	if (ap->ops->error_handler) {
		struct scsi_cmnd *scmd, *tmp;
		int nr_timedout = 0;

		spin_lock_irqsave(ap->lock, flags);

		/* This must occur under the ap->lock as we don't want
		   a polled recovery to race the real interrupt handler

		   The lost_interrupt handler checks for any completed but
		   non-notified command and completes much like an IRQ handler.

		   We then fall into the error recovery code which will treat
		   this as if normal completion won the race */

		if (ap->ops->lost_interrupt)
			ap->ops->lost_interrupt(ap);

		list_for_each_entry_safe(scmd, tmp, eh_work_q, eh_entry) {
			struct ata_queued_cmd *qc;

			for (i = 0; i < ATA_MAX_QUEUE; i++) {
				qc = __ata_qc_from_tag(ap, i);
				if (qc->flags & ATA_QCFLAG_ACTIVE &&
				    qc->scsicmd == scmd)
					break;
			}

			if (i < ATA_MAX_QUEUE) {
				/* the scmd has an associated qc */
				if (!(qc->flags & ATA_QCFLAG_FAILED)) {
					/* which hasn't failed yet, timeout */
					qc->err_mask |= AC_ERR_TIMEOUT;
					qc->flags |= ATA_QCFLAG_FAILED;
					nr_timedout++;
				}
			} else {
				/* Normal completion occurred after
				 * SCSI timeout but before this point.
				 * Successfully complete it.
				 */
				scmd->retries = scmd->allowed;
				scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
			}
		}

		/* If we have timed out qcs.  They belong to EH from
		 * this point but the state of the controller is
		 * unknown.  Freeze the port to make sure the IRQ
		 * handler doesn't diddle with those qcs.  This must
		 * be done atomically w.r.t. setting QCFLAG_FAILED.
		 */
		if (nr_timedout)
			__ata_port_freeze(ap);

		spin_unlock_irqrestore(ap->lock, flags);

		/* initialize eh_tries */
		ap->eh_tries = ATA_EH_MAX_TRIES;
	} else
		spin_unlock_wait(ap->lock);

}
EXPORT_SYMBOL(ata_scsi_cmd_error_handler);

/**
 * ata_scsi_port_error_handler - recover the port after the commands
 * @host:	SCSI host containing the port
 * @ap:		the ATA port
 *
 * Handle the recovery of the port @ap after all the commands
 * have been recovered.
 */
void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
{
	unsigned long flags;

	/* invoke error handler */
	if (ap->ops->error_handler) {
		struct ata_link *link;

		/* acquire EH ownership */
		ata_eh_acquire(ap);
 repeat:
		/* kill fast drain timer */
		del_timer_sync(&ap->fastdrain_timer);

		/* process port resume request */
		ata_eh_handle_port_resume(ap);

		/* fetch & clear EH info */
		spin_lock_irqsave(ap->lock, flags);

		ata_for_each_link(link, ap, HOST_FIRST) {
			struct ata_eh_context *ehc = &link->eh_context;
			struct ata_device *dev;

			memset(&link->eh_context, 0, sizeof(link->eh_context));
			link->eh_context.i = link->eh_info;
			memset(&link->eh_info, 0, sizeof(link->eh_info));

			ata_for_each_dev(dev, link, ENABLED) {
				int devno = dev->devno;

				ehc->saved_xfer_mode[devno] = dev->xfer_mode;
				if (ata_ncq_enabled(dev))
					ehc->saved_ncq_enabled |= 1 << devno;
			}
		}

		ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
		ap->pflags &= ~ATA_PFLAG_EH_PENDING;
		ap->excl_link = NULL;	/* don't maintain exclusion over EH */

		spin_unlock_irqrestore(ap->lock, flags);

		/* invoke EH, skip if unloading or suspended */
		if (!(ap->pflags & (ATA_PFLAG_UNLOADING | ATA_PFLAG_SUSPENDED)))
			ap->ops->error_handler(ap);
		else {
			/* if unloading, commence suicide */
			if ((ap->pflags & ATA_PFLAG_UNLOADING) &&
			    !(ap->pflags & ATA_PFLAG_UNLOADED))
				ata_eh_unload(ap);
			ata_eh_finish(ap);
		}

		/* process port suspend request */
		ata_eh_handle_port_suspend(ap);

		/* Exception might have happened after ->error_handler
		 * recovered the port but before this point.  Repeat
		 * EH in such case.
		 */
		spin_lock_irqsave(ap->lock, flags);

		if (ap->pflags & ATA_PFLAG_EH_PENDING) {
			if (--ap->eh_tries) {
				spin_unlock_irqrestore(ap->lock, flags);
				goto repeat;
			}
			ata_port_err(ap,
				     "EH pending after %d tries, giving up\n",
				     ATA_EH_MAX_TRIES);
			ap->pflags &= ~ATA_PFLAG_EH_PENDING;
		}

		/* this run is complete, make sure EH info is clear */
		ata_for_each_link(link, ap, HOST_FIRST)
			memset(&link->eh_info, 0, sizeof(link->eh_info));

		/* end eh (clear host_eh_scheduled) while holding
		 * ap->lock such that if exception occurs after this
		 * point but before EH completion, SCSI midlayer will
		 * re-initiate EH.
		 */
		ap->ops->end_eh(ap);

		spin_unlock_irqrestore(ap->lock, flags);
		ata_eh_release(ap);
	} else {
		WARN_ON(ata_qc_from_tag(ap, ap->link.active_tag) == NULL);
		ap->ops->eng_timeout(ap);
	}

	scsi_eh_flush_done_q(&ap->eh_done_q);

	/* clean up */
	spin_lock_irqsave(ap->lock, flags);

	if (ap->pflags & ATA_PFLAG_LOADING)
		ap->pflags &= ~ATA_PFLAG_LOADING;
	else if (ap->pflags & ATA_PFLAG_SCSI_HOTPLUG)
		schedule_delayed_work(&ap->hotplug_task, 0);

	if (ap->pflags & ATA_PFLAG_RECOVERED)
		ata_port_info(ap, "EH complete\n");

	ap->pflags &= ~(ATA_PFLAG_SCSI_HOTPLUG | ATA_PFLAG_RECOVERED);

	/* tell wait_eh that we're done */
	ap->pflags &= ~ATA_PFLAG_EH_IN_PROGRESS;
	wake_up_all(&ap->eh_wait_q);

	spin_unlock_irqrestore(ap->lock, flags);
}
EXPORT_SYMBOL_GPL(ata_scsi_port_error_handler);

/**
 *	ata_port_wait_eh - Wait for the currently pending EH to complete
 *	@ap: Port to wait EH for
 *
 *	Wait until the currently pending EH is complete.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
void ata_port_wait_eh(struct ata_port *ap)
{
	unsigned long flags;
	DEFINE_WAIT(wait);

 retry:
	spin_lock_irqsave(ap->lock, flags);

	while (ap->pflags & (ATA_PFLAG_EH_PENDING | ATA_PFLAG_EH_IN_PROGRESS)) {
		prepare_to_wait(&ap->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
		spin_unlock_irqrestore(ap->lock, flags);
		schedule();
		spin_lock_irqsave(ap->lock, flags);
	}
	finish_wait(&ap->eh_wait_q, &wait);

	spin_unlock_irqrestore(ap->lock, flags);

	/* make sure SCSI EH is complete */
	if (scsi_host_in_recovery(ap->scsi_host)) {
		ata_msleep(ap, 10);
		goto retry;
	}
}
EXPORT_SYMBOL_GPL(ata_port_wait_eh);

static int ata_eh_nr_in_flight(struct ata_port *ap)
{
	unsigned int tag;
	int nr = 0;

	/* count only non-internal commands */
	for (tag = 0; tag < ATA_MAX_QUEUE - 1; tag++)
		if (ata_qc_from_tag(ap, tag))
			nr++;

	return nr;
}

void ata_eh_fastdrain_timerfn(unsigned long arg)
{
	struct ata_port *ap = (void *)arg;
	unsigned long flags;
	int cnt;

	spin_lock_irqsave(ap->lock, flags);

	cnt = ata_eh_nr_in_flight(ap);

	/* are we done? */
	if (!cnt)
		goto out_unlock;

	if (cnt == ap->fastdrain_cnt) {
		unsigned int tag;

		/* No progress during the last interval, tag all
		 * in-flight qcs as timed out and freeze the port.
		 */
		for (tag = 0; tag < ATA_MAX_QUEUE - 1; tag++) {
			struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);
			if (qc)
				qc->err_mask |= AC_ERR_TIMEOUT;
		}

		ata_port_freeze(ap);
	} else {
		/* some qcs have finished, give it another chance */
		ap->fastdrain_cnt = cnt;
		ap->fastdrain_timer.expires =
			ata_deadline(jiffies, ATA_EH_FASTDRAIN_INTERVAL);
		add_timer(&ap->fastdrain_timer);
	}

 out_unlock:
	spin_unlock_irqrestore(ap->lock, flags);
}

/**
 *	ata_eh_set_pending - set ATA_PFLAG_EH_PENDING and activate fast drain
 *	@ap: target ATA port
 *	@fastdrain: activate fast drain
 *
 *	Set ATA_PFLAG_EH_PENDING and activate fast drain if @fastdrain
 *	is non-zero and EH wasn't pending before.  Fast drain ensures
 *	that EH kicks in in timely manner.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static void ata_eh_set_pending(struct ata_port *ap, int fastdrain)
{
	int cnt;

	/* already scheduled? */
	if (ap->pflags & ATA_PFLAG_EH_PENDING)
		return;

	ap->pflags |= ATA_PFLAG_EH_PENDING;

	if (!fastdrain)
		return;

	/* do we have in-flight qcs? */
	cnt = ata_eh_nr_in_flight(ap);
	if (!cnt)
		return;

	/* activate fast drain */
	ap->fastdrain_cnt = cnt;
	ap->fastdrain_timer.expires =
		ata_deadline(jiffies, ATA_EH_FASTDRAIN_INTERVAL);
	add_timer(&ap->fastdrain_timer);
}

/**
 *	ata_qc_schedule_eh - schedule qc for error handling
 *	@qc: command to schedule error handling for
 *
 *	Schedule error handling for @qc.  EH will kick in as soon as
 *	other commands are drained.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct request_queue *q = qc->scsicmd->device->request_queue;
	unsigned long flags;

	WARN_ON(!ap->ops->error_handler);

	qc->flags |= ATA_QCFLAG_FAILED;
	ata_eh_set_pending(ap, 1);

	/* The following will fail if timeout has already expired.
	 * ata_scsi_error() takes care of such scmds on EH entry.
	 * Note that ATA_QCFLAG_FAILED is unconditionally set after
	 * this function completes.
	 */
	spin_lock_irqsave(q->queue_lock, flags);
	blk_abort_request(qc->scsicmd->request);
	spin_unlock_irqrestore(q->queue_lock, flags);
}

/**
 * ata_std_sched_eh - non-libsas ata_ports issue eh with this common routine
 * @ap: ATA port to schedule EH for
 *
 *	LOCKING: inherited from ata_port_schedule_eh
 *	spin_lock_irqsave(host lock)
 */
void ata_std_sched_eh(struct ata_port *ap)
{
	WARN_ON(!ap->ops->error_handler);

	if (ap->pflags & ATA_PFLAG_INITIALIZING)
		return;

	ata_eh_set_pending(ap, 1);
	scsi_schedule_eh(ap->scsi_host);

	DPRINTK("port EH scheduled\n");
}
EXPORT_SYMBOL_GPL(ata_std_sched_eh);

/**
 * ata_std_end_eh - non-libsas ata_ports complete eh with this common routine
 * @ap: ATA port to end EH for
 *
 * In the libata object model there is a 1:1 mapping of ata_port to
 * shost, so host fields can be directly manipulated under ap->lock, in
 * the libsas case we need to hold a lock at the ha->level to coordinate
 * these events.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
void ata_std_end_eh(struct ata_port *ap)
{
	struct Scsi_Host *host = ap->scsi_host;

	host->host_eh_scheduled = 0;
}
EXPORT_SYMBOL(ata_std_end_eh);


/**
 *	ata_port_schedule_eh - schedule error handling without a qc
 *	@ap: ATA port to schedule EH for
 *
 *	Schedule error handling for @ap.  EH will kick in as soon as
 *	all commands are drained.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
void ata_port_schedule_eh(struct ata_port *ap)
{
	/* see: ata_std_sched_eh, unless you know better */
	ap->ops->sched_eh(ap);
}

static int ata_do_link_abort(struct ata_port *ap, struct ata_link *link)
{
	int tag, nr_aborted = 0;

	WARN_ON(!ap->ops->error_handler);

	/* we're gonna abort all commands, no need for fast drain */
	ata_eh_set_pending(ap, 0);

	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);

		if (qc && (!link || qc->dev->link == link)) {
			qc->flags |= ATA_QCFLAG_FAILED;
			ata_qc_complete(qc);
			nr_aborted++;
		}
	}

	if (!nr_aborted)
		ata_port_schedule_eh(ap);

	return nr_aborted;
}

/**
 *	ata_link_abort - abort all qc's on the link
 *	@link: ATA link to abort qc's for
 *
 *	Abort all active qc's active on @link and schedule EH.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Number of aborted qc's.
 */
int ata_link_abort(struct ata_link *link)
{
	return ata_do_link_abort(link->ap, link);
}

/**
 *	ata_port_abort - abort all qc's on the port
 *	@ap: ATA port to abort qc's for
 *
 *	Abort all active qc's of @ap and schedule EH.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host_set lock)
 *
 *	RETURNS:
 *	Number of aborted qc's.
 */
int ata_port_abort(struct ata_port *ap)
{
	return ata_do_link_abort(ap, NULL);
}

/**
 *	__ata_port_freeze - freeze port
 *	@ap: ATA port to freeze
 *
 *	This function is called when HSM violation or some other
 *	condition disrupts normal operation of the port.  Frozen port
 *	is not allowed to perform any operation until the port is
 *	thawed, which usually follows a successful reset.
 *
 *	ap->ops->freeze() callback can be used for freezing the port
 *	hardware-wise (e.g. mask interrupt and stop DMA engine).  If a
 *	port cannot be frozen hardware-wise, the interrupt handler
 *	must ack and clear interrupts unconditionally while the port
 *	is frozen.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
static void __ata_port_freeze(struct ata_port *ap)
{
	WARN_ON(!ap->ops->error_handler);

	if (ap->ops->freeze)
		ap->ops->freeze(ap);

	ap->pflags |= ATA_PFLAG_FROZEN;

	DPRINTK("ata%u port frozen\n", ap->print_id);
}

/**
 *	ata_port_freeze - abort & freeze port
 *	@ap: ATA port to freeze
 *
 *	Abort and freeze @ap.  The freeze operation must be called
 *	first, because some hardware requires special operations
 *	before the taskfile registers are accessible.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	Number of aborted commands.
 */
int ata_port_freeze(struct ata_port *ap)
{
	int nr_aborted;

	WARN_ON(!ap->ops->error_handler);

	__ata_port_freeze(ap);
	nr_aborted = ata_port_abort(ap);

	return nr_aborted;
}

/**
 *	sata_async_notification - SATA async notification handler
 *	@ap: ATA port where async notification is received
 *
 *	Handler to be called when async notification via SDB FIS is
 *	received.  This function schedules EH if necessary.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 *
 *	RETURNS:
 *	1 if EH is scheduled, 0 otherwise.
 */
int sata_async_notification(struct ata_port *ap)
{
	u32 sntf;
	int rc;

	if (!(ap->flags & ATA_FLAG_AN))
		return 0;

	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
	if (rc == 0)
		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);

	if (!sata_pmp_attached(ap) || rc) {
		/* PMP is not attached or SNTF is not available */
		if (!sata_pmp_attached(ap)) {
			/* PMP is not attached.  Check whether ATAPI
			 * AN is configured.  If so, notify media
			 * change.
			 */
			struct ata_device *dev = ap->link.device;

			if ((dev->class == ATA_DEV_ATAPI) &&
			    (dev->flags & ATA_DFLAG_AN))
				ata_scsi_media_change_notify(dev);
			return 0;
		} else {
			/* PMP is attached but SNTF is not available.
			 * ATAPI async media change notification is
			 * not used.  The PMP must be reporting PHY
			 * status change, schedule EH.
			 */
			ata_port_schedule_eh(ap);
			return 1;
		}
	} else {
		/* PMP is attached and SNTF is available */
		struct ata_link *link;

		/* check and notify ATAPI AN */
		ata_for_each_link(link, ap, EDGE) {
			if (!(sntf & (1 << link->pmp)))
				continue;

			if ((link->device->class == ATA_DEV_ATAPI) &&
			    (link->device->flags & ATA_DFLAG_AN))
				ata_scsi_media_change_notify(link->device);
		}

		/* If PMP is reporting that PHY status of some
		 * downstream ports has changed, schedule EH.
		 */
		if (sntf & (1 << SATA_PMP_CTRL_PORT)) {
			ata_port_schedule_eh(ap);
			return 1;
		}

		return 0;
	}
}

/**
 *	ata_eh_freeze_port - EH helper to freeze port
 *	@ap: ATA port to freeze
 *
 *	Freeze @ap.
 *
 *	LOCKING:
 *	None.
 */
void ata_eh_freeze_port(struct ata_port *ap)
{
	unsigned long flags;

	if (!ap->ops->error_handler)
		return;

	spin_lock_irqsave(ap->lock, flags);
	__ata_port_freeze(ap);
	spin_unlock_irqrestore(ap->lock, flags);
}

/**
 *	ata_port_thaw_port - EH helper to thaw port
 *	@ap: ATA port to thaw
 *
 *	Thaw frozen port @ap.
 *
 *	LOCKING:
 *	None.
 */
void ata_eh_thaw_port(struct ata_port *ap)
{
	unsigned long flags;

	if (!ap->ops->error_handler)
		return;

	spin_lock_irqsave(ap->lock, flags);

	ap->pflags &= ~ATA_PFLAG_FROZEN;

	if (ap->ops->thaw)
		ap->ops->thaw(ap);

	spin_unlock_irqrestore(ap->lock, flags);

	DPRINTK("ata%u port thawed\n", ap->print_id);
}

static void ata_eh_scsidone(struct scsi_cmnd *scmd)
{
	/* nada */
}

static void __ata_eh_qc_complete(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct scsi_cmnd *scmd = qc->scsicmd;
	unsigned long flags;

	spin_lock_irqsave(ap->lock, flags);
	qc->scsidone = ata_eh_scsidone;
	__ata_qc_complete(qc);
	WARN_ON(ata_tag_valid(qc->tag));
	spin_unlock_irqrestore(ap->lock, flags);

	scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
}

/**
 *	ata_eh_qc_complete - Complete an active ATA command from EH
 *	@qc: Command to complete
 *
 *	Indicate to the mid and upper layers that an ATA command has
 *	completed.  To be used from EH.
 */
void ata_eh_qc_complete(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;
	scmd->retries = scmd->allowed;
	__ata_eh_qc_complete(qc);
}

/**
 *	ata_eh_qc_retry - Tell midlayer to retry an ATA command after EH
 *	@qc: Command to retry
 *
 *	Indicate to the mid and upper layers that an ATA command
 *	should be retried.  To be used from EH.
 *
 *	SCSI midlayer limits the number of retries to scmd->allowed.
 *	scmd->allowed is incremented for commands which get retried
 *	due to unrelated failures (qc->err_mask is zero).
 */
void ata_eh_qc_retry(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;
	if (!qc->err_mask)
		scmd->allowed++;
	__ata_eh_qc_complete(qc);
}

/**
 *	ata_dev_disable - disable ATA device
 *	@dev: ATA device to disable
 *
 *	Disable @dev.
 *
 *	Locking:
 *	EH context.
 */
void ata_dev_disable(struct ata_device *dev)
{
	if (!ata_dev_enabled(dev))
		return;

	if (ata_msg_drv(dev->link->ap))
		ata_dev_warn(dev, "disabled\n");
	ata_acpi_on_disable(dev);
	ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO0 | ATA_DNXFER_QUIET);
	dev->class++;

	/* From now till the next successful probe, ering is used to
	 * track probe failures.  Clear accumulated device error info.
	 */
	ata_ering_clear(&dev->ering);
}

/**
 *	ata_eh_detach_dev - detach ATA device
 *	@dev: ATA device to detach
 *
 *	Detach @dev.
 *
 *	LOCKING:
 *	None.
 */
void ata_eh_detach_dev(struct ata_device *dev)
{
	struct ata_link *link = dev->link;
	struct ata_port *ap = link->ap;
	struct ata_eh_context *ehc = &link->eh_context;
	unsigned long flags;

	ata_dev_disable(dev);

	spin_lock_irqsave(ap->lock, flags);

	dev->flags &= ~ATA_DFLAG_DETACH;

	if (ata_scsi_offline_dev(dev)) {
		dev->flags |= ATA_DFLAG_DETACHED;
		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
	}

	/* clear per-dev EH info */
	ata_eh_clear_action(link, dev, &link->eh_info, ATA_EH_PERDEV_MASK);
	ata_eh_clear_action(link, dev, &link->eh_context.i, ATA_EH_PERDEV_MASK);
	ehc->saved_xfer_mode[dev->devno] = 0;
	ehc->saved_ncq_enabled &= ~(1 << dev->devno);

	spin_unlock_irqrestore(ap->lock, flags);
}

/**
 *	ata_eh_about_to_do - about to perform eh_action
 *	@link: target ATA link
 *	@dev: target ATA dev for per-dev action (can be NULL)
 *	@action: action about to be performed
 *
 *	Called just before performing EH actions to clear related bits
 *	in @link->eh_info such that eh actions are not unnecessarily
 *	repeated.
 *
 *	LOCKING:
 *	None.
 */
void ata_eh_about_to_do(struct ata_link *link, struct ata_device *dev,
			unsigned int action)
{
	struct ata_port *ap = link->ap;
	struct ata_eh_info *ehi = &link->eh_info;
	struct ata_eh_context *ehc = &link->eh_context;
	unsigned long flags;

	spin_lock_irqsave(ap->lock, flags);

	ata_eh_clear_action(link, dev, ehi, action);

	/* About to take EH action, set RECOVERED.  Ignore actions on
	 * slave links as master will do them again.
	 */
	if (!(ehc->i.flags & ATA_EHI_QUIET) && link != ap->slave_link)
		ap->pflags |= ATA_PFLAG_RECOVERED;

	spin_unlock_irqrestore(ap->lock, flags);
}

/**
 *	ata_eh_done - EH action complete
*	@ap: target ATA port
 *	@dev: target ATA dev for per-dev action (can be NULL)
 *	@action: action just completed
 *
 *	Called right after performing EH actions to clear related bits
 *	in @link->eh_context.
 *
 *	LOCKING:
 *	None.
 */
void ata_eh_done(struct ata_link *link, struct ata_device *dev,
		 unsigned int action)
{
	struct ata_eh_context *ehc = &link->eh_context;

	ata_eh_clear_action(link, dev, &ehc->i, action);
}

/**
 *	ata_err_string - convert err_mask to descriptive string
 *	@err_mask: error mask to convert to string
 *
 *	Convert @err_mask to descriptive string.  Errors are
 *	prioritized according to severity and only the most severe
 *	error is reported.
 *
 *	LOCKING:
 *	None.
 *
 *	RETURNS:
 *	Descriptive string for @err_mask
 */
static const char *ata_err_string(unsigned int err_mask)
{
	if (err_mask & AC_ERR_HOST_BUS)
		return "host bus error";
	if (err_mask & AC_ERR_ATA_BUS)
		return "ATA bus error";
	if (err_mask & AC_ERR_TIMEOUT)
		return "timeout";
	if (err_mask & AC_ERR_HSM)
		return "HSM violation";
	if (err_mask & AC_ERR_SYSTEM)
		return "internal error";
	if (err_mask & AC_ERR_MEDIA)
		return "media error";
	if (err_mask & AC_ERR_INVALID)
		return "invalid argument";
	if (err_mask & AC_ERR_DEV)
		return "device error";
	return "unknown error";
}

/**
 *	ata_read_log_page - read a specific log page
 *	@dev: target device
 *	@log: log to read
 *	@page: page to read
 *	@buf: buffer to store read page
 *	@sectors: number of sectors to read
 *
 *	Read log page using READ_LOG_EXT command.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	0 on success, AC_ERR_* mask otherwise.
 */
unsigned int ata_read_log_page(struct ata_device *dev, u8 log,
			       u8 page, void *buf, unsigned int sectors)
{
	unsigned long ap_flags = dev->link->ap->flags;
	struct ata_taskfile tf;
	unsigned int err_mask;
	bool dma = false;

	DPRINTK("read log page - log 0x%x, page 0x%x\n", log, page);

	/*
	 * Return error without actually issuing the command on controllers
	 * which e.g. lockup on a read log page.
	 */
	if (ap_flags & ATA_FLAG_NO_LOG_PAGE)
		return AC_ERR_DEV;

retry:
	ata_tf_init(dev, &tf);
	if (dev->dma_mode && ata_id_has_read_log_dma_ext(dev->id) &&
	    !(dev->horkage & ATA_HORKAGE_NO_NCQ_LOG)) {
		tf.command = ATA_CMD_READ_LOG_DMA_EXT;
		tf.protocol = ATA_PROT_DMA;
		dma = true;
	} else {
		tf.command = ATA_CMD_READ_LOG_EXT;
		tf.protocol = ATA_PROT_PIO;
		dma = false;
	}
	tf.lbal = log;
	tf.lbam = page;
	tf.nsect = sectors;
	tf.hob_nsect = sectors >> 8;
	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_LBA48 | ATA_TFLAG_DEVICE;

	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
				     buf, sectors * ATA_SECT_SIZE, 0);

	if (err_mask && dma) {
		dev->horkage |= ATA_HORKAGE_NO_NCQ_LOG;
		ata_dev_warn(dev, "READ LOG DMA EXT failed, trying unqueued\n");
		goto retry;
	}

	DPRINTK("EXIT, err_mask=%x\n", err_mask);
	return err_mask;
}

/**
 *	ata_eh_read_log_10h - Read log page 10h for NCQ error details
 *	@dev: Device to read log page 10h from
 *	@tag: Resulting tag of the failed command
 *	@tf: Resulting taskfile registers of the failed command
 *
 *	Read log page 10h to obtain NCQ error details and clear error
 *	condition.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	0 on success, -errno otherwise.
 */
static int ata_eh_read_log_10h(struct ata_device *dev,
			       int *tag, struct ata_taskfile *tf)
{
	u8 *buf = dev->link->ap->sector_buf;
	unsigned int err_mask;
	u8 csum;
	int i;

	err_mask = ata_read_log_page(dev, ATA_LOG_SATA_NCQ, 0, buf, 1);
	if (err_mask)
		return -EIO;

	csum = 0;
	for (i = 0; i < ATA_SECT_SIZE; i++)
		csum += buf[i];
	if (csum)
		ata_dev_warn(dev, "invalid checksum 0x%x on log page 10h\n",
			     csum);

	if (buf[0] & 0x80)
		return -ENOENT;

	*tag = buf[0] & 0x1f;

	tf->command = buf[2];
	tf->feature = buf[3];
	tf->lbal = buf[4];
	tf->lbam = buf[5];
	tf->lbah = buf[6];
	tf->device = buf[7];
	tf->hob_lbal = buf[8];
	tf->hob_lbam = buf[9];
	tf->hob_lbah = buf[10];
	tf->nsect = buf[12];
	tf->hob_nsect = buf[13];
	if (ata_id_has_ncq_autosense(dev->id))
		tf->auxiliary = buf[14] << 16 | buf[15] << 8 | buf[16];

	return 0;
}

/**
 *	atapi_eh_tur - perform ATAPI TEST_UNIT_READY
 *	@dev: target ATAPI device
 *	@r_sense_key: out parameter for sense_key
 *
 *	Perform ATAPI TEST_UNIT_READY.
 *
 *	LOCKING:
 *	EH context (may sleep).
 *
 *	RETURNS:
 *	0 on success, AC_ERR_* mask on failure.
 */
unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
{
	u8 cdb[ATAPI_CDB_LEN] = { TEST_UNIT_READY, 0, 0, 0, 0, 0 };
	struct ata_taskfile tf;
	unsigned int err_mask;

	ata_tf_init(dev, &tf);

	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	tf.command = ATA_CMD_PACKET;
	tf.protocol = ATAPI_PROT_NODATA;

	err_mask = ata_exec_internal(dev, &tf, cdb, DMA_NONE, NULL, 0, 0);
	if (err_mask == AC_ERR_DEV)
		*r_sense_key = tf.feature >> 4;
	return err_mask;
}

/**
 *	ata_eh_request_sense - perform REQUEST_SENSE_DATA_EXT
 *	@dev: device to perform REQUEST_SENSE_SENSE_DATA_EXT to
 *	@cmd: scsi command for which the sense code should be set
 *
 *	Perform REQUEST_SENSE_DATA_EXT after the device reported CHECK
 *	SENSE.  This function is an EH helper.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
static void ata_eh_request_sense(struct ata_queued_cmd *qc,
				 struct scsi_cmnd *cmd)
{
	struct ata_device *dev = qc->dev;
	struct ata_taskfile tf;
	unsigned int err_mask;

	if (qc->ap->pflags & ATA_PFLAG_FROZEN) {
		ata_dev_warn(dev, "sense data available but port frozen\n");
		return;
	}

	if (!cmd || qc->flags & ATA_QCFLAG_SENSE_VALID)
		return;

	if (!ata_id_sense_reporting_enabled(dev->id)) {
		ata_dev_warn(qc->dev, "sense data reporting disabled\n");
		return;
	}

	DPRINTK("ATA request sense\n");

	ata_tf_init(dev, &tf);
	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	tf.flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
	tf.command = ATA_CMD_REQ_SENSE_DATA;
	tf.protocol = ATA_PROT_NODATA;

	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
	/* Ignore err_mask; ATA_ERR might be set */
	if (tf.command & ATA_SENSE) {
		ata_scsi_set_sense(dev, cmd, tf.lbah, tf.lbam, tf.lbal);
		qc->flags |= ATA_QCFLAG_SENSE_VALID;
	} else {
		ata_dev_warn(dev, "request sense failed stat %02x emask %x\n",
			     tf.command, err_mask);
	}
}

/**
 *	atapi_eh_request_sense - perform ATAPI REQUEST_SENSE
 *	@dev: device to perform REQUEST_SENSE to
 *	@sense_buf: result sense data buffer (SCSI_SENSE_BUFFERSIZE bytes long)
 *	@dfl_sense_key: default sense key to use
 *
 *	Perform ATAPI REQUEST_SENSE after the device reported CHECK
 *	SENSE.  This function is EH helper.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	0 on success, AC_ERR_* mask on failure
 */
unsigned int atapi_eh_request_sense(struct ata_device *dev,
					   u8 *sense_buf, u8 dfl_sense_key)
{
	u8 cdb[ATAPI_CDB_LEN] =
		{ REQUEST_SENSE, 0, 0, 0, SCSI_SENSE_BUFFERSIZE, 0 };
	struct ata_port *ap = dev->link->ap;
	struct ata_taskfile tf;

	DPRINTK("ATAPI request sense\n");

	memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);

	/* initialize sense_buf with the error register,
	 * for the case where they are -not- overwritten
	 */
	sense_buf[0] = 0x70;
	sense_buf[2] = dfl_sense_key;

	/* some devices time out if garbage left in tf */
	ata_tf_init(dev, &tf);

	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	tf.command = ATA_CMD_PACKET;

	/* is it pointless to prefer PIO for "safety reasons"? */
	if (ap->flags & ATA_FLAG_PIO_DMA) {
		tf.protocol = ATAPI_PROT_DMA;
		tf.feature |= ATAPI_PKT_DMA;
	} else {
		tf.protocol = ATAPI_PROT_PIO;
		tf.lbam = SCSI_SENSE_BUFFERSIZE;
		tf.lbah = 0;
	}

	return ata_exec_internal(dev, &tf, cdb, DMA_FROM_DEVICE,
				 sense_buf, SCSI_SENSE_BUFFERSIZE, 0);
}

/**
 *	ata_eh_analyze_serror - analyze SError for a failed port
 *	@link: ATA link to analyze SError for
 *
 *	Analyze SError if available and further determine cause of
 *	failure.
 *
 *	LOCKING:
 *	None.
 */
static void ata_eh_analyze_serror(struct ata_link *link)
{
	struct ata_eh_context *ehc = &link->eh_context;
	u32 serror = ehc->i.serror;
	unsigned int err_mask = 0, action = 0;
	u32 hotplug_mask;

	if (serror & (SERR_PERSISTENT | SERR_DATA)) {
		err_mask |= AC_ERR_ATA_BUS;
		action |= ATA_EH_RESET;
	}
	if (serror & SERR_PROTOCOL) {
		err_mask |= AC_ERR_HSM;
		action |= ATA_EH_RESET;
	}
	if (serror & SERR_INTERNAL) {
		err_mask |= AC_ERR_SYSTEM;
		action |= ATA_EH_RESET;
	}

	/* Determine whether a hotplug event has occurred.  Both
	 * SError.N/X are considered hotplug events for enabled or
	 * host links.  For disabled PMP links, only N bit is
	 * considered as X bit is left at 1 for link plugging.
	 */
	if (link->lpm_policy > ATA_LPM_MAX_POWER)
		hotplug_mask = 0;	/* hotplug doesn't work w/ LPM */
	else if (!(link->flags & ATA_LFLAG_DISABLED) || ata_is_host_link(link))
		hotplug_mask = SERR_PHYRDY_CHG | SERR_DEV_XCHG;
	else
		hotplug_mask = SERR_PHYRDY_CHG;

	if (serror & hotplug_mask)
		ata_ehi_hotplugged(&ehc->i);

	ehc->i.err_mask |= err_mask;
	ehc->i.action |= action;
}

/**
 *	ata_eh_analyze_ncq_error - analyze NCQ error
 *	@link: ATA link to analyze NCQ error for
 *
 *	Read log page 10h, determine the offending qc and acquire
 *	error status TF.  For NCQ device errors, all LLDDs have to do
 *	is setting AC_ERR_DEV in ehi->err_mask.  This function takes
 *	care of the rest.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
void ata_eh_analyze_ncq_error(struct ata_link *link)
{
	struct ata_port *ap = link->ap;
	struct ata_eh_context *ehc = &link->eh_context;
	struct ata_device *dev = link->device;
	struct ata_queued_cmd *qc;
	struct ata_taskfile tf;
	int tag, rc;

	/* if frozen, we can't do much */
	if (ap->pflags & ATA_PFLAG_FROZEN)
		return;

	/* is it NCQ device error? */
	if (!link->sactive || !(ehc->i.err_mask & AC_ERR_DEV))
		return;

	/* has LLDD analyzed already? */
	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		qc = __ata_qc_from_tag(ap, tag);

		if (!(qc->flags & ATA_QCFLAG_FAILED))
			continue;

		if (qc->err_mask)
			return;
	}

	/* okay, this error is ours */
	memset(&tf, 0, sizeof(tf));
	rc = ata_eh_read_log_10h(dev, &tag, &tf);
	if (rc) {
		ata_link_err(link, "failed to read log page 10h (errno=%d)\n",
			     rc);
		return;
	}

	if (!(link->sactive & (1 << tag))) {
		ata_link_err(link, "log page 10h reported inactive tag %d\n",
			     tag);
		return;
	}

	/* we've got the perpetrator, condemn it */
	qc = __ata_qc_from_tag(ap, tag);
	memcpy(&qc->result_tf, &tf, sizeof(tf));
	qc->result_tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
	if ((qc->result_tf.command & ATA_SENSE) || qc->result_tf.auxiliary) {
		char sense_key, asc, ascq;

		sense_key = (qc->result_tf.auxiliary >> 16) & 0xff;
		asc = (qc->result_tf.auxiliary >> 8) & 0xff;
		ascq = qc->result_tf.auxiliary & 0xff;
		ata_scsi_set_sense(dev, qc->scsicmd, sense_key, asc, ascq);
		ata_scsi_set_sense_information(dev, qc->scsicmd,
					       &qc->result_tf);
		qc->flags |= ATA_QCFLAG_SENSE_VALID;
	}

	ehc->i.err_mask &= ~AC_ERR_DEV;
}

/**
 *	ata_eh_analyze_tf - analyze taskfile of a failed qc
 *	@qc: qc to analyze
 *	@tf: Taskfile registers to analyze
 *
 *	Analyze taskfile of @qc and further determine cause of
 *	failure.  This function also requests ATAPI sense data if
 *	available.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	Determined recovery action
 */
static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc,
				      const struct ata_taskfile *tf)
{
	unsigned int tmp, action = 0;
	u8 stat = tf->command, err = tf->feature;

	if ((stat & (ATA_BUSY | ATA_DRQ | ATA_DRDY)) != ATA_DRDY) {
		qc->err_mask |= AC_ERR_HSM;
		return ATA_EH_RESET;
	}

	if (stat & (ATA_ERR | ATA_DF)) {
		qc->err_mask |= AC_ERR_DEV;
		/*
		 * Sense data reporting does not work if the
		 * device fault bit is set.
		 */
		if (stat & ATA_DF)
			stat &= ~ATA_SENSE;
	} else {
		return 0;
	}

	switch (qc->dev->class) {
	case ATA_DEV_ATA:
	case ATA_DEV_ZAC:
		if (stat & ATA_SENSE)
			ata_eh_request_sense(qc, qc->scsicmd);
		if (err & ATA_ICRC)
			qc->err_mask |= AC_ERR_ATA_BUS;
		if (err & (ATA_UNC | ATA_AMNF))
			qc->err_mask |= AC_ERR_MEDIA;
		if (err & ATA_IDNF)
			qc->err_mask |= AC_ERR_INVALID;
		break;

	case ATA_DEV_ATAPI:
		if (!(qc->ap->pflags & ATA_PFLAG_FROZEN)) {
			tmp = atapi_eh_request_sense(qc->dev,
						qc->scsicmd->sense_buffer,
						qc->result_tf.feature >> 4);
			if (!tmp)
				qc->flags |= ATA_QCFLAG_SENSE_VALID;
			else
				qc->err_mask |= tmp;
		}
	}

	if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
		int ret = scsi_check_sense(qc->scsicmd);
		/*
		 * SUCCESS here means that the sense code could
		 * evaluated and should be passed to the upper layers
		 * for correct evaluation.
		 * FAILED means the sense code could not interpreted
		 * and the device would need to be reset.
		 * NEEDS_RETRY and ADD_TO_MLQUEUE means that the
		 * command would need to be retried.
		 */
		if (ret == NEEDS_RETRY || ret == ADD_TO_MLQUEUE) {
			qc->flags |= ATA_QCFLAG_RETRY;
			qc->err_mask |= AC_ERR_OTHER;
		} else if (ret != SUCCESS) {
			qc->err_mask |= AC_ERR_HSM;
		}
	}
	if (qc->err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT | AC_ERR_ATA_BUS))
		action |= ATA_EH_RESET;

	return action;
}

static int ata_eh_categorize_error(unsigned int eflags, unsigned int err_mask,
				   int *xfer_ok)
{
	int base = 0;

	if (!(eflags & ATA_EFLAG_DUBIOUS_XFER))
		*xfer_ok = 1;

	if (!*xfer_ok)
		base = ATA_ECAT_DUBIOUS_NONE;

	if (err_mask & AC_ERR_ATA_BUS)
		return base + ATA_ECAT_ATA_BUS;

	if (err_mask & AC_ERR_TIMEOUT)
		return base + ATA_ECAT_TOUT_HSM;

	if (eflags & ATA_EFLAG_IS_IO) {
		if (err_mask & AC_ERR_HSM)
			return base + ATA_ECAT_TOUT_HSM;
		if ((err_mask &
		     (AC_ERR_DEV|AC_ERR_MEDIA|AC_ERR_INVALID)) == AC_ERR_DEV)
			return base + ATA_ECAT_UNK_DEV;
	}

	return 0;
}

struct speed_down_verdict_arg {
	u64 since;
	int xfer_ok;
	int nr_errors[ATA_ECAT_NR];
};

static int speed_down_verdict_cb(struct ata_ering_entry *ent, void *void_arg)
{
	struct speed_down_verdict_arg *arg = void_arg;
	int cat;

	if ((ent->eflags & ATA_EFLAG_OLD_ER) || (ent->timestamp < arg->since))
		return -1;

	cat = ata_eh_categorize_error(ent->eflags, ent->err_mask,
				      &arg->xfer_ok);
	arg->nr_errors[cat]++;

	return 0;
}

/**
 *	ata_eh_speed_down_verdict - Determine speed down verdict
 *	@dev: Device of interest
 *
 *	This function examines error ring of @dev and determines
 *	whether NCQ needs to be turned off, transfer speed should be
 *	stepped down, or falling back to PIO is necessary.
 *
 *	ECAT_ATA_BUS	: ATA_BUS error for any command
 *
 *	ECAT_TOUT_HSM	: TIMEOUT for any command or HSM violation for
 *			  IO commands
 *
 *	ECAT_UNK_DEV	: Unknown DEV error for IO commands
 *
 *	ECAT_DUBIOUS_*	: Identical to above three but occurred while
 *			  data transfer hasn't been verified.
 *
 *	Verdicts are
 *
 *	NCQ_OFF		: Turn off NCQ.
 *
 *	SPEED_DOWN	: Speed down transfer speed but don't fall back
 *			  to PIO.
 *
 *	FALLBACK_TO_PIO	: Fall back to PIO.
 *
 *	Even if multiple verdicts are returned, only one action is
 *	taken per error.  An action triggered by non-DUBIOUS errors
 *	clears ering, while one triggered by DUBIOUS_* errors doesn't.
 *	This is to expedite speed down decisions right after device is
 *	initially configured.
 *
 *	The followings are speed down rules.  #1 and #2 deal with
 *	DUBIOUS errors.
 *
 *	1. If more than one DUBIOUS_ATA_BUS or DUBIOUS_TOUT_HSM errors
 *	   occurred during last 5 mins, SPEED_DOWN and FALLBACK_TO_PIO.
 *
 *	2. If more than one DUBIOUS_TOUT_HSM or DUBIOUS_UNK_DEV errors
 *	   occurred during last 5 mins, NCQ_OFF.
 *
 *	3. If more than 8 ATA_BUS, TOUT_HSM or UNK_DEV errors
 *	   occurred during last 5 mins, FALLBACK_TO_PIO
 *
 *	4. If more than 3 TOUT_HSM or UNK_DEV errors occurred
 *	   during last 10 mins, NCQ_OFF.
 *
 *	5. If more than 3 ATA_BUS or TOUT_HSM errors, or more than 6
 *	   UNK_DEV errors occurred during last 10 mins, SPEED_DOWN.
 *
 *	LOCKING:
 *	Inherited from caller.
 *
 *	RETURNS:
 *	OR of ATA_EH_SPDN_* flags.
 */
static unsigned int ata_eh_speed_down_verdict(struct ata_device *dev)
{
	const u64 j5mins = 5LLU * 60 * HZ, j10mins = 10LLU * 60 * HZ;
	u64 j64 = get_jiffies_64();
	struct speed_down_verdict_arg arg;
	unsigned int verdict = 0;

	/* scan past 5 mins of error history */
	memset(&arg, 0, sizeof(arg));
	arg.since = j64 - min(j64, j5mins);
	ata_ering_map(&dev->ering, speed_down_verdict_cb, &arg);

	if (arg.nr_errors[ATA_ECAT_DUBIOUS_ATA_BUS] +
	    arg.nr_errors[ATA_ECAT_DUBIOUS_TOUT_HSM] > 1)
		verdict |= ATA_EH_SPDN_SPEED_DOWN |
			ATA_EH_SPDN_FALLBACK_TO_PIO | ATA_EH_SPDN_KEEP_ERRORS;

	if (arg.nr_errors[ATA_ECAT_DUBIOUS_TOUT_HSM] +
	    arg.nr_errors[ATA_ECAT_DUBIOUS_UNK_DEV] > 1)
		verdict |= ATA_EH_SPDN_NCQ_OFF | ATA_EH_SPDN_KEEP_ERRORS;

	if (arg.nr_errors[ATA_ECAT_ATA_BUS] +
	    arg.nr_errors[ATA_ECAT_TOUT_HSM] +
	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 6)
		verdict |= ATA_EH_SPDN_FALLBACK_TO_PIO;

	/* scan past 10 mins of error history */
	memset(&arg, 0, sizeof(arg));
	arg.since = j64 - min(j64, j10mins);
	ata_ering_map(&dev->ering, speed_down_verdict_cb, &arg);

	if (arg.nr_errors[ATA_ECAT_TOUT_HSM] +
	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 3)
		verdict |= ATA_EH_SPDN_NCQ_OFF;

	if (arg.nr_errors[ATA_ECAT_ATA_BUS] +
	    arg.nr_errors[ATA_ECAT_TOUT_HSM] > 3 ||
	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 6)
		verdict |= ATA_EH_SPDN_SPEED_DOWN;

	return verdict;
}

/**
 *	ata_eh_speed_down - record error and speed down if necessary
 *	@dev: Failed device
 *	@eflags: mask of ATA_EFLAG_* flags
 *	@err_mask: err_mask of the error
 *
 *	Record error and examine error history to determine whether
 *	adjusting transmission speed is necessary.  It also sets
 *	transmission limits appropriately if such adjustment is
 *	necessary.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	Determined recovery action.
 */
static unsigned int ata_eh_speed_down(struct ata_device *dev,
				unsigned int eflags, unsigned int err_mask)
{
	struct ata_link *link = ata_dev_phys_link(dev);
	int xfer_ok = 0;
	unsigned int verdict;
	unsigned int action = 0;

	/* don't bother if Cat-0 error */
	if (ata_eh_categorize_error(eflags, err_mask, &xfer_ok) == 0)
		return 0;

	/* record error and determine whether speed down is necessary */
	ata_ering_record(&dev->ering, eflags, err_mask);
	verdict = ata_eh_speed_down_verdict(dev);

	/* turn off NCQ? */
	if ((verdict & ATA_EH_SPDN_NCQ_OFF) &&
	    (dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ |
			   ATA_DFLAG_NCQ_OFF)) == ATA_DFLAG_NCQ) {
		dev->flags |= ATA_DFLAG_NCQ_OFF;
		ata_dev_warn(dev, "NCQ disabled due to excessive errors\n");
		goto done;
	}

	/* speed down? */
	if (verdict & ATA_EH_SPDN_SPEED_DOWN) {
		/* speed down SATA link speed if possible */
		if (sata_down_spd_limit(link, 0) == 0) {
			action |= ATA_EH_RESET;
			goto done;
		}

		/* lower transfer mode */
		if (dev->spdn_cnt < 2) {
			static const int dma_dnxfer_sel[] =
				{ ATA_DNXFER_DMA, ATA_DNXFER_40C };
			static const int pio_dnxfer_sel[] =
				{ ATA_DNXFER_PIO, ATA_DNXFER_FORCE_PIO0 };
			int sel;

			if (dev->xfer_shift != ATA_SHIFT_PIO)
				sel = dma_dnxfer_sel[dev->spdn_cnt];
			else
				sel = pio_dnxfer_sel[dev->spdn_cnt];

			dev->spdn_cnt++;

			if (ata_down_xfermask_limit(dev, sel) == 0) {
				action |= ATA_EH_RESET;
				goto done;
			}
		}
	}

	/* Fall back to PIO?  Slowing down to PIO is meaningless for
	 * SATA ATA devices.  Consider it only for PATA and SATAPI.
	 */
	if ((verdict & ATA_EH_SPDN_FALLBACK_TO_PIO) && (dev->spdn_cnt >= 2) &&
	    (link->ap->cbl != ATA_CBL_SATA || dev->class == ATA_DEV_ATAPI) &&
	    (dev->xfer_shift != ATA_SHIFT_PIO)) {
		if (ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO) == 0) {
			dev->spdn_cnt = 0;
			action |= ATA_EH_RESET;
			goto done;
		}
	}

	return 0;
 done:
	/* device has been slowed down, blow error history */
	if (!(verdict & ATA_EH_SPDN_KEEP_ERRORS))
		ata_ering_clear(&dev->ering);
	return action;
}

/**
 *	ata_eh_worth_retry - analyze error and decide whether to retry
 *	@qc: qc to possibly retry
 *
 *	Look at the cause of the error and decide if a retry
 * 	might be useful or not.  We don't want to retry media errors
 *	because the drive itself has probably already taken 10-30 seconds
 *	doing its own internal retries before reporting the failure.
 */
static inline int ata_eh_worth_retry(struct ata_queued_cmd *qc)
{
	if (qc->err_mask & AC_ERR_MEDIA)
		return 0;	/* don't retry media errors */
	if (qc->flags & ATA_QCFLAG_IO)
		return 1;	/* otherwise retry anything from fs stack */
	if (qc->err_mask & AC_ERR_INVALID)
		return 0;	/* don't retry these */
	return qc->err_mask != AC_ERR_DEV;  /* retry if not dev error */
}

/**
 *	ata_eh_link_autopsy - analyze error and determine recovery action
 *	@link: host link to perform autopsy on
 *
 *	Analyze why @link failed and determine which recovery actions
 *	are needed.  This function also sets more detailed AC_ERR_*
 *	values and fills sense data for ATAPI CHECK SENSE.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
static void ata_eh_link_autopsy(struct ata_link *link)
{
	struct ata_port *ap = link->ap;
	struct ata_eh_context *ehc = &link->eh_context;
	struct ata_device *dev;
	unsigned int all_err_mask = 0, eflags = 0;
	int tag;
	u32 serror;
	int rc;

	DPRINTK("ENTER\n");

	if (ehc->i.flags & ATA_EHI_NO_AUTOPSY)
		return;

	/* obtain and analyze SError */
	rc = sata_scr_read(link, SCR_ERROR, &serror);
	if (rc == 0) {
		ehc->i.serror |= serror;
		ata_eh_analyze_serror(link);
	} else if (rc != -EOPNOTSUPP) {
		/* SError read failed, force reset and probing */
		ehc->i.probe_mask |= ATA_ALL_DEVICES;
		ehc->i.action |= ATA_EH_RESET;
		ehc->i.err_mask |= AC_ERR_OTHER;
	}

	/* analyze NCQ failure */
	ata_eh_analyze_ncq_error(link);

	/* any real error trumps AC_ERR_OTHER */
	if (ehc->i.err_mask & ~AC_ERR_OTHER)
		ehc->i.err_mask &= ~AC_ERR_OTHER;

	all_err_mask |= ehc->i.err_mask;

	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);

		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
		    ata_dev_phys_link(qc->dev) != link)
			continue;

		/* inherit upper level err_mask */
		qc->err_mask |= ehc->i.err_mask;

		/* analyze TF */
		ehc->i.action |= ata_eh_analyze_tf(qc, &qc->result_tf);

		/* DEV errors are probably spurious in case of ATA_BUS error */
		if (qc->err_mask & AC_ERR_ATA_BUS)
			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_MEDIA |
					  AC_ERR_INVALID);

		/* any real error trumps unknown error */
		if (qc->err_mask & ~AC_ERR_OTHER)
			qc->err_mask &= ~AC_ERR_OTHER;

		/* SENSE_VALID trumps dev/unknown error and revalidation */
		if (qc->flags & ATA_QCFLAG_SENSE_VALID)
			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_OTHER);

		/* determine whether the command is worth retrying */
		if (ata_eh_worth_retry(qc))
			qc->flags |= ATA_QCFLAG_RETRY;

		/* accumulate error info */
		ehc->i.dev = qc->dev;
		all_err_mask |= qc->err_mask;
		if (qc->flags & ATA_QCFLAG_IO)
			eflags |= ATA_EFLAG_IS_IO;
		trace_ata_eh_link_autopsy_qc(qc);
	}

	/* enforce default EH actions */
	if (ap->pflags & ATA_PFLAG_FROZEN ||
	    all_err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT))
		ehc->i.action |= ATA_EH_RESET;
	else if (((eflags & ATA_EFLAG_IS_IO) && all_err_mask) ||
		 (!(eflags & ATA_EFLAG_IS_IO) && (all_err_mask & ~AC_ERR_DEV)))
		ehc->i.action |= ATA_EH_REVALIDATE;

	/* If we have offending qcs and the associated failed device,
	 * perform per-dev EH action only on the offending device.
	 */
	if (ehc->i.dev) {
		ehc->i.dev_action[ehc->i.dev->devno] |=
			ehc->i.action & ATA_EH_PERDEV_MASK;
		ehc->i.action &= ~ATA_EH_PERDEV_MASK;
	}

	/* propagate timeout to host link */
	if ((all_err_mask & AC_ERR_TIMEOUT) && !ata_is_host_link(link))
		ap->link.eh_context.i.err_mask |= AC_ERR_TIMEOUT;

	/* record error and consider speeding down */
	dev = ehc->i.dev;
	if (!dev && ((ata_link_max_devices(link) == 1 &&
		      ata_dev_enabled(link->device))))
	    dev = link->device;

	if (dev) {
		if (dev->flags & ATA_DFLAG_DUBIOUS_XFER)
			eflags |= ATA_EFLAG_DUBIOUS_XFER;
		ehc->i.action |= ata_eh_speed_down(dev, eflags, all_err_mask);
	}
	trace_ata_eh_link_autopsy(dev, ehc->i.action, all_err_mask);
	DPRINTK("EXIT\n");
}

/**
 *	ata_eh_autopsy - analyze error and determine recovery action
 *	@ap: host port to perform autopsy on
 *
 *	Analyze all links of @ap and determine why they failed and
 *	which recovery actions are needed.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
void ata_eh_autopsy(struct ata_port *ap)
{
	struct ata_link *link;

	ata_for_each_link(link, ap, EDGE)
		ata_eh_link_autopsy(link);

	/* Handle the frigging slave link.  Autopsy is done similarly
	 * but actions and flags are transferred over to the master
	 * link and handled from there.
	 */
	if (ap->slave_link) {
		struct ata_eh_context *mehc = &ap->link.eh_context;
		struct ata_eh_context *sehc = &ap->slave_link->eh_context;

		/* transfer control flags from master to slave */
		sehc->i.flags |= mehc->i.flags & ATA_EHI_TO_SLAVE_MASK;

		/* perform autopsy on the slave link */
		ata_eh_link_autopsy(ap->slave_link);

		/* transfer actions from slave to master and clear slave */
		ata_eh_about_to_do(ap->slave_link, NULL, ATA_EH_ALL_ACTIONS);
		mehc->i.action		|= sehc->i.action;
		mehc->i.dev_action[1]	|= sehc->i.dev_action[1];
		mehc->i.flags		|= sehc->i.flags;
		ata_eh_done(ap->slave_link, NULL, ATA_EH_ALL_ACTIONS);
	}

	/* Autopsy of fanout ports can affect host link autopsy.
	 * Perform host link autopsy last.
	 */
	if (sata_pmp_attached(ap))
		ata_eh_link_autopsy(&ap->link);
}

/**
 *	ata_get_cmd_descript - get description for ATA command
 *	@command: ATA command code to get description for
 *
 *	Return a textual description of the given command, or NULL if the
 *	command is not known.
 *
 *	LOCKING:
 *	None
 */
const char *ata_get_cmd_descript(u8 command)
{
#ifdef CONFIG_ATA_VERBOSE_ERROR
	static const struct
	{
		u8 command;
		const char *text;
	} cmd_descr[] = {
		{ ATA_CMD_DEV_RESET,		"DEVICE RESET" },
		{ ATA_CMD_CHK_POWER,		"CHECK POWER MODE" },
		{ ATA_CMD_STANDBY,		"STANDBY" },
		{ ATA_CMD_IDLE,			"IDLE" },
		{ ATA_CMD_EDD,			"EXECUTE DEVICE DIAGNOSTIC" },
		{ ATA_CMD_DOWNLOAD_MICRO,	"DOWNLOAD MICROCODE" },
		{ ATA_CMD_DOWNLOAD_MICRO_DMA,	"DOWNLOAD MICROCODE DMA" },
		{ ATA_CMD_NOP,			"NOP" },
		{ ATA_CMD_FLUSH,		"FLUSH CACHE" },
		{ ATA_CMD_FLUSH_EXT,		"FLUSH CACHE EXT" },
		{ ATA_CMD_ID_ATA,		"IDENTIFY DEVICE" },
		{ ATA_CMD_ID_ATAPI,		"IDENTIFY PACKET DEVICE" },
		{ ATA_CMD_SERVICE,		"SERVICE" },
		{ ATA_CMD_READ,			"READ DMA" },
		{ ATA_CMD_READ_EXT,		"READ DMA EXT" },
		{ ATA_CMD_READ_QUEUED,		"READ DMA QUEUED" },
		{ ATA_CMD_READ_STREAM_EXT,	"READ STREAM EXT" },
		{ ATA_CMD_READ_STREAM_DMA_EXT,  "READ STREAM DMA EXT" },
		{ ATA_CMD_WRITE,		"WRITE DMA" },
		{ ATA_CMD_WRITE_EXT,		"WRITE DMA EXT" },
		{ ATA_CMD_WRITE_QUEUED,		"WRITE DMA QUEUED EXT" },
		{ ATA_CMD_WRITE_STREAM_EXT,	"WRITE STREAM EXT" },
		{ ATA_CMD_WRITE_STREAM_DMA_EXT, "WRITE STREAM DMA EXT" },
		{ ATA_CMD_WRITE_FUA_EXT,	"WRITE DMA FUA EXT" },
		{ ATA_CMD_WRITE_QUEUED_FUA_EXT, "WRITE DMA QUEUED FUA EXT" },
		{ ATA_CMD_FPDMA_READ,		"READ FPDMA QUEUED" },
		{ ATA_CMD_FPDMA_WRITE,		"WRITE FPDMA QUEUED" },
		{ ATA_CMD_FPDMA_SEND,		"SEND FPDMA QUEUED" },
		{ ATA_CMD_FPDMA_RECV,		"RECEIVE FPDMA QUEUED" },
		{ ATA_CMD_PIO_READ,		"READ SECTOR(S)" },
		{ ATA_CMD_PIO_READ_EXT,		"READ SECTOR(S) EXT" },
		{ ATA_CMD_PIO_WRITE,		"WRITE SECTOR(S)" },
		{ ATA_CMD_PIO_WRITE_EXT,	"WRITE SECTOR(S) EXT" },
		{ ATA_CMD_READ_MULTI,		"READ MULTIPLE" },
		{ ATA_CMD_READ_MULTI_EXT,	"READ MULTIPLE EXT" },
		{ ATA_CMD_WRITE_MULTI,		"WRITE MULTIPLE" },
		{ ATA_CMD_WRITE_MULTI_EXT,	"WRITE MULTIPLE EXT" },
		{ ATA_CMD_WRITE_MULTI_FUA_EXT,	"WRITE MULTIPLE FUA EXT" },
		{ ATA_CMD_SET_FEATURES,		"SET FEATURES" },
		{ ATA_CMD_SET_MULTI,		"SET MULTIPLE MODE" },
		{ ATA_CMD_VERIFY,		"READ VERIFY SECTOR(S)" },
		{ ATA_CMD_VERIFY_EXT,		"READ VERIFY SECTOR(S) EXT" },
		{ ATA_CMD_WRITE_UNCORR_EXT,	"WRITE UNCORRECTABLE EXT" },
		{ ATA_CMD_STANDBYNOW1,		"STANDBY IMMEDIATE" },
		{ ATA_CMD_IDLEIMMEDIATE,	"IDLE IMMEDIATE" },
		{ ATA_CMD_SLEEP,		"SLEEP" },
		{ ATA_CMD_INIT_DEV_PARAMS,	"INITIALIZE DEVICE PARAMETERS" },
		{ ATA_CMD_READ_NATIVE_MAX,	"READ NATIVE MAX ADDRESS" },
		{ ATA_CMD_READ_NATIVE_MAX_EXT,	"READ NATIVE MAX ADDRESS EXT" },
		{ ATA_CMD_SET_MAX,		"SET MAX ADDRESS" },
		{ ATA_CMD_SET_MAX_EXT,		"SET MAX ADDRESS EXT" },
		{ ATA_CMD_READ_LOG_EXT,		"READ LOG EXT" },
		{ ATA_CMD_WRITE_LOG_EXT,	"WRITE LOG EXT" },
		{ ATA_CMD_READ_LOG_DMA_EXT,	"READ LOG DMA EXT" },
		{ ATA_CMD_WRITE_LOG_DMA_EXT,	"WRITE LOG DMA EXT" },
		{ ATA_CMD_TRUSTED_NONDATA,	"TRUSTED NON-DATA" },
		{ ATA_CMD_TRUSTED_RCV,		"TRUSTED RECEIVE" },
		{ ATA_CMD_TRUSTED_RCV_DMA,	"TRUSTED RECEIVE DMA" },
		{ ATA_CMD_TRUSTED_SND,		"TRUSTED SEND" },
		{ ATA_CMD_TRUSTED_SND_DMA,	"TRUSTED SEND DMA" },
		{ ATA_CMD_PMP_READ,		"READ BUFFER" },
		{ ATA_CMD_PMP_READ_DMA,		"READ BUFFER DMA" },
		{ ATA_CMD_PMP_WRITE,		"WRITE BUFFER" },
		{ ATA_CMD_PMP_WRITE_DMA,	"WRITE BUFFER DMA" },
		{ ATA_CMD_CONF_OVERLAY,		"DEVICE CONFIGURATION OVERLAY" },
		{ ATA_CMD_SEC_SET_PASS,		"SECURITY SET PASSWORD" },
		{ ATA_CMD_SEC_UNLOCK,		"SECURITY UNLOCK" },
		{ ATA_CMD_SEC_ERASE_PREP,	"SECURITY ERASE PREPARE" },
		{ ATA_CMD_SEC_ERASE_UNIT,	"SECURITY ERASE UNIT" },
		{ ATA_CMD_SEC_FREEZE_LOCK,	"SECURITY FREEZE LOCK" },
		{ ATA_CMD_SEC_DISABLE_PASS,	"SECURITY DISABLE PASSWORD" },
		{ ATA_CMD_CONFIG_STREAM,	"CONFIGURE STREAM" },
		{ ATA_CMD_SMART,		"SMART" },
		{ ATA_CMD_MEDIA_LOCK,		"DOOR LOCK" },
		{ ATA_CMD_MEDIA_UNLOCK,		"DOOR UNLOCK" },
		{ ATA_CMD_DSM,			"DATA SET MANAGEMENT" },
		{ ATA_CMD_CHK_MED_CRD_TYP,	"CHECK MEDIA CARD TYPE" },
		{ ATA_CMD_CFA_REQ_EXT_ERR,	"CFA REQUEST EXTENDED ERROR" },
		{ ATA_CMD_CFA_WRITE_NE,		"CFA WRITE SECTORS WITHOUT ERASE" },
		{ ATA_CMD_CFA_TRANS_SECT,	"CFA TRANSLATE SECTOR" },
		{ ATA_CMD_CFA_ERASE,		"CFA ERASE SECTORS" },
		{ ATA_CMD_CFA_WRITE_MULT_NE,	"CFA WRITE MULTIPLE WITHOUT ERASE" },
		{ ATA_CMD_REQ_SENSE_DATA,	"REQUEST SENSE DATA EXT" },
		{ ATA_CMD_SANITIZE_DEVICE,	"SANITIZE DEVICE" },
		{ ATA_CMD_ZAC_MGMT_IN,		"ZAC MANAGEMENT IN" },
		{ ATA_CMD_ZAC_MGMT_OUT,		"ZAC MANAGEMENT OUT" },
		{ ATA_CMD_READ_LONG,		"READ LONG (with retries)" },
		{ ATA_CMD_READ_LONG_ONCE,	"READ LONG (without retries)" },
		{ ATA_CMD_WRITE_LONG,		"WRITE LONG (with retries)" },
		{ ATA_CMD_WRITE_LONG_ONCE,	"WRITE LONG (without retries)" },
		{ ATA_CMD_RESTORE,		"RECALIBRATE" },
		{ 0,				NULL } /* terminate list */
	};

	unsigned int i;
	for (i = 0; cmd_descr[i].text; i++)
		if (cmd_descr[i].command == command)
			return cmd_descr[i].text;
#endif

	return NULL;
}
EXPORT_SYMBOL_GPL(ata_get_cmd_descript);

/**
 *	ata_eh_link_report - report error handling to user
 *	@link: ATA link EH is going on
 *
 *	Report EH to user.
 *
 *	LOCKING:
 *	None.
 */
static void ata_eh_link_report(struct ata_link *link)
{
	struct ata_port *ap = link->ap;
	struct ata_eh_context *ehc = &link->eh_context;
	const char *frozen, *desc;
	char tries_buf[6] = "";
	int tag, nr_failed = 0;

	if (ehc->i.flags & ATA_EHI_QUIET)
		return;

	desc = NULL;
	if (ehc->i.desc[0] != '\0')
		desc = ehc->i.desc;

	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);

		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
		    ata_dev_phys_link(qc->dev) != link ||
		    ((qc->flags & ATA_QCFLAG_QUIET) &&
		     qc->err_mask == AC_ERR_DEV))
			continue;
		if (qc->flags & ATA_QCFLAG_SENSE_VALID && !qc->err_mask)
			continue;

		nr_failed++;
	}

	if (!nr_failed && !ehc->i.err_mask)
		return;

	frozen = "";
	if (ap->pflags & ATA_PFLAG_FROZEN)
		frozen = " frozen";

	if (ap->eh_tries < ATA_EH_MAX_TRIES)
		snprintf(tries_buf, sizeof(tries_buf), " t%d",
			 ap->eh_tries);

	if (ehc->i.dev) {
		ata_dev_err(ehc->i.dev, "exception Emask 0x%x "
			    "SAct 0x%x SErr 0x%x action 0x%x%s%s\n",
			    ehc->i.err_mask, link->sactive, ehc->i.serror,
			    ehc->i.action, frozen, tries_buf);
		if (desc)
			ata_dev_err(ehc->i.dev, "%s\n", desc);
	} else {
		ata_link_err(link, "exception Emask 0x%x "
			     "SAct 0x%x SErr 0x%x action 0x%x%s%s\n",
			     ehc->i.err_mask, link->sactive, ehc->i.serror,
			     ehc->i.action, frozen, tries_buf);
		if (desc)
			ata_link_err(link, "%s\n", desc);
	}

#ifdef CONFIG_ATA_VERBOSE_ERROR
	if (ehc->i.serror)
		ata_link_err(link,
		  "SError: { %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s}\n",
		  ehc->i.serror & SERR_DATA_RECOVERED ? "RecovData " : "",
		  ehc->i.serror & SERR_COMM_RECOVERED ? "RecovComm " : "",
		  ehc->i.serror & SERR_DATA ? "UnrecovData " : "",
		  ehc->i.serror & SERR_PERSISTENT ? "Persist " : "",
		  ehc->i.serror & SERR_PROTOCOL ? "Proto " : "",
		  ehc->i.serror & SERR_INTERNAL ? "HostInt " : "",
		  ehc->i.serror & SERR_PHYRDY_CHG ? "PHYRdyChg " : "",
		  ehc->i.serror & SERR_PHY_INT_ERR ? "PHYInt " : "",
		  ehc->i.serror & SERR_COMM_WAKE ? "CommWake " : "",
		  ehc->i.serror & SERR_10B_8B_ERR ? "10B8B " : "",
		  ehc->i.serror & SERR_DISPARITY ? "Dispar " : "",
		  ehc->i.serror & SERR_CRC ? "BadCRC " : "",
		  ehc->i.serror & SERR_HANDSHAKE ? "Handshk " : "",
		  ehc->i.serror & SERR_LINK_SEQ_ERR ? "LinkSeq " : "",
		  ehc->i.serror & SERR_TRANS_ST_ERROR ? "TrStaTrns " : "",
		  ehc->i.serror & SERR_UNRECOG_FIS ? "UnrecFIS " : "",
		  ehc->i.serror & SERR_DEV_XCHG ? "DevExch " : "");
#endif

	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
		struct ata_taskfile *cmd = &qc->tf, *res = &qc->result_tf;
		char data_buf[20] = "";
		char cdb_buf[70] = "";

		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
		    ata_dev_phys_link(qc->dev) != link || !qc->err_mask)
			continue;

		if (qc->dma_dir != DMA_NONE) {
			static const char *dma_str[] = {
				[DMA_BIDIRECTIONAL]	= "bidi",
				[DMA_TO_DEVICE]		= "out",
				[DMA_FROM_DEVICE]	= "in",
			};
			static const char *prot_str[] = {
				[ATA_PROT_UNKNOWN]	= "unknown",
				[ATA_PROT_NODATA]	= "nodata",
				[ATA_PROT_PIO]		= "pio",
				[ATA_PROT_DMA]		= "dma",
				[ATA_PROT_NCQ]		= "ncq dma",
				[ATA_PROT_NCQ_NODATA]	= "ncq nodata",
				[ATAPI_PROT_NODATA]	= "nodata",
				[ATAPI_PROT_PIO]	= "pio",
				[ATAPI_PROT_DMA]	= "dma",
			};

			snprintf(data_buf, sizeof(data_buf), " %s %u %s",
				 prot_str[qc->tf.protocol], qc->nbytes,
				 dma_str[qc->dma_dir]);
		}

		if (ata_is_atapi(qc->tf.protocol)) {
			const u8 *cdb = qc->cdb;
			size_t cdb_len = qc->dev->cdb_len;

			if (qc->scsicmd) {
				cdb = qc->scsicmd->cmnd;
				cdb_len = qc->scsicmd->cmd_len;
			}
			__scsi_format_command(cdb_buf, sizeof(cdb_buf),
					      cdb, cdb_len);
		} else {
			const char *descr = ata_get_cmd_descript(cmd->command);
			if (descr)
				ata_dev_err(qc->dev, "failed command: %s\n",
					    descr);
		}

		ata_dev_err(qc->dev,
			"cmd %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
			"tag %d%s\n         %s"
			"res %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
			"Emask 0x%x (%s)%s\n",
			cmd->command, cmd->feature, cmd->nsect,
			cmd->lbal, cmd->lbam, cmd->lbah,
			cmd->hob_feature, cmd->hob_nsect,
			cmd->hob_lbal, cmd->hob_lbam, cmd->hob_lbah,
			cmd->device, qc->tag, data_buf, cdb_buf,
			res->command, res->feature, res->nsect,
			res->lbal, res->lbam, res->lbah,
			res->hob_feature, res->hob_nsect,
			res->hob_lbal, res->hob_lbam, res->hob_lbah,
			res->device, qc->err_mask, ata_err_string(qc->err_mask),
			qc->err_mask & AC_ERR_NCQ ? " <F>" : "");

#ifdef CONFIG_ATA_VERBOSE_ERROR
		if (res->command & (ATA_BUSY | ATA_DRDY | ATA_DF | ATA_DRQ |
				    ATA_SENSE | ATA_ERR)) {
			if (res->command & ATA_BUSY)
				ata_dev_err(qc->dev, "status: { Busy }\n");
			else
				ata_dev_err(qc->dev, "status: { %s%s%s%s%s}\n",
				  res->command & ATA_DRDY ? "DRDY " : "",
				  res->command & ATA_DF ? "DF " : "",
				  res->command & ATA_DRQ ? "DRQ " : "",
				  res->command & ATA_SENSE ? "SENSE " : "",
				  res->command & ATA_ERR ? "ERR " : "");
		}

		if (cmd->command != ATA_CMD_PACKET &&
		    (res->feature & (ATA_ICRC | ATA_UNC | ATA_AMNF |
				     ATA_IDNF | ATA_ABORTED)))
			ata_dev_err(qc->dev, "error: { %s%s%s%s%s}\n",
			  res->feature & ATA_ICRC ? "ICRC " : "",
			  res->feature & ATA_UNC ? "UNC " : "",
			  res->feature & ATA_AMNF ? "AMNF " : "",
			  res->feature & ATA_IDNF ? "IDNF " : "",
			  res->feature & ATA_ABORTED ? "ABRT " : "");
#endif
	}
}

/**
 *	ata_eh_report - report error handling to user
 *	@ap: ATA port to report EH about
 *
 *	Report EH to user.
 *
 *	LOCKING:
 *	None.
 */
void ata_eh_report(struct ata_port *ap)
{
	struct ata_link *link;

	ata_for_each_link(link, ap, HOST_FIRST)
		ata_eh_link_report(link);
}

static int ata_do_reset(struct ata_link *link, ata_reset_fn_t reset,
			unsigned int *classes, unsigned long deadline,
			bool clear_classes)
{
	struct ata_device *dev;

	if (clear_classes)
		ata_for_each_dev(dev, link, ALL)
			classes[dev->devno] = ATA_DEV_UNKNOWN;

	return reset(link, classes, deadline);
}

static int ata_eh_followup_srst_needed(struct ata_link *link, int rc)
{
	if ((link->flags & ATA_LFLAG_NO_SRST) || ata_link_offline(link))
		return 0;
	if (rc == -EAGAIN)
		return 1;
	if (sata_pmp_supported(link->ap) && ata_is_host_link(link))
		return 1;
	return 0;
}

int ata_eh_reset(struct ata_link *link, int classify,
		 ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
		 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
{
	struct ata_port *ap = link->ap;
	struct ata_link *slave = ap->slave_link;
	struct ata_eh_context *ehc = &link->eh_context;
	struct ata_eh_context *sehc = slave ? &slave->eh_context : NULL;
	unsigned int *classes = ehc->classes;
	unsigned int lflags = link->flags;
	int verbose = !(ehc->i.flags & ATA_EHI_QUIET);
	int max_tries = 0, try = 0;
	struct ata_link *failed_link;
	struct ata_device *dev;
	unsigned long deadline, now;
	ata_reset_fn_t reset;
	unsigned long flags;
	u32 sstatus;
	int nr_unknown, rc;

	/*
	 * Prepare to reset
	 */
	while (ata_eh_reset_timeouts[max_tries] != ULONG_MAX)
		max_tries++;
	if (link->flags & ATA_LFLAG_RST_ONCE)
		max_tries = 1;
	if (link->flags & ATA_LFLAG_NO_HRST)
		hardreset = NULL;
	if (link->flags & ATA_LFLAG_NO_SRST)
		softreset = NULL;

	/* make sure each reset attempt is at least COOL_DOWN apart */
	if (ehc->i.flags & ATA_EHI_DID_RESET) {
		now = jiffies;
		WARN_ON(time_after(ehc->last_reset, now));
		deadline = ata_deadline(ehc->last_reset,
					ATA_EH_RESET_COOL_DOWN);
		if (time_before(now, deadline))
			schedule_timeout_uninterruptible(deadline - now);
	}

	spin_lock_irqsave(ap->lock, flags);
	ap->pflags |= ATA_PFLAG_RESETTING;
	spin_unlock_irqrestore(ap->lock, flags);

	ata_eh_about_to_do(link, NULL, ATA_EH_RESET);

	ata_for_each_dev(dev, link, ALL) {
		/* If we issue an SRST then an ATA drive (not ATAPI)
		 * may change configuration and be in PIO0 timing. If
		 * we do a hard reset (or are coming from power on)
		 * this is true for ATA or ATAPI. Until we've set a
		 * suitable controller mode we should not touch the
		 * bus as we may be talking too fast.
		 */
		dev->pio_mode = XFER_PIO_0;
		dev->dma_mode = 0xff;

		/* If the controller has a pio mode setup function
		 * then use it to set the chipset to rights. Don't
		 * touch the DMA setup as that will be dealt with when
		 * configuring devices.
		 */
		if (ap->ops->set_piomode)
			ap->ops->set_piomode(ap, dev);
	}

	/* prefer hardreset */
	reset = NULL;
	ehc->i.action &= ~ATA_EH_RESET;
	if (hardreset) {
		reset = hardreset;
		ehc->i.action |= ATA_EH_HARDRESET;
	} else if (softreset) {
		reset = softreset;
		ehc->i.action |= ATA_EH_SOFTRESET;
	}

	if (prereset) {
		unsigned long deadline = ata_deadline(jiffies,
						      ATA_EH_PRERESET_TIMEOUT);

		if (slave) {
			sehc->i.action &= ~ATA_EH_RESET;
			sehc->i.action |= ehc->i.action;
		}

		rc = prereset(link, deadline);

		/* If present, do prereset on slave link too.  Reset
		 * is skipped iff both master and slave links report
		 * -ENOENT or clear ATA_EH_RESET.
		 */
		if (slave && (rc == 0 || rc == -ENOENT)) {
			int tmp;

			tmp = prereset(slave, deadline);
			if (tmp != -ENOENT)
				rc = tmp;

			ehc->i.action |= sehc->i.action;
		}

		if (rc) {
			if (rc == -ENOENT) {
				ata_link_dbg(link, "port disabled--ignoring\n");
				ehc->i.action &= ~ATA_EH_RESET;

				ata_for_each_dev(dev, link, ALL)
					classes[dev->devno] = ATA_DEV_NONE;

				rc = 0;
			} else
				ata_link_err(link,
					     "prereset failed (errno=%d)\n",
					     rc);
			goto out;
		}

		/* prereset() might have cleared ATA_EH_RESET.  If so,
		 * bang classes, thaw and return.
		 */
		if (reset && !(ehc->i.action & ATA_EH_RESET)) {
			ata_for_each_dev(dev, link, ALL)
				classes[dev->devno] = ATA_DEV_NONE;
			if ((ap->pflags & ATA_PFLAG_FROZEN) &&
			    ata_is_host_link(link))
				ata_eh_thaw_port(ap);
			rc = 0;
			goto out;
		}
	}

 retry:
	/*
	 * Perform reset
	 */
	if (ata_is_host_link(link))
		ata_eh_freeze_port(ap);

	deadline = ata_deadline(jiffies, ata_eh_reset_timeouts[try++]);

	if (reset) {
		if (verbose)
			ata_link_info(link, "%s resetting link\n",
				      reset == softreset ? "soft" : "hard");

		/* mark that this EH session started with reset */
		ehc->last_reset = jiffies;
		if (reset == hardreset)
			ehc->i.flags |= ATA_EHI_DID_HARDRESET;
		else
			ehc->i.flags |= ATA_EHI_DID_SOFTRESET;

		rc = ata_do_reset(link, reset, classes, deadline, true);
		if (rc && rc != -EAGAIN) {
			failed_link = link;
			goto fail;
		}

		/* hardreset slave link if existent */
		if (slave && reset == hardreset) {
			int tmp;

			if (verbose)
				ata_link_info(slave, "hard resetting link\n");

			ata_eh_about_to_do(slave, NULL, ATA_EH_RESET);
			tmp = ata_do_reset(slave, reset, classes, deadline,
					   false);
			switch (tmp) {
			case -EAGAIN:
				rc = -EAGAIN;
			case 0:
				break;
			default:
				failed_link = slave;
				rc = tmp;
				goto fail;
			}
		}

		/* perform follow-up SRST if necessary */
		if (reset == hardreset &&
		    ata_eh_followup_srst_needed(link, rc)) {
			reset = softreset;

			if (!reset) {
				ata_link_err(link,
	     "follow-up softreset required but no softreset available\n");
				failed_link = link;
				rc = -EINVAL;
				goto fail;
			}

			ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
			rc = ata_do_reset(link, reset, classes, deadline, true);
			if (rc) {
				failed_link = link;
				goto fail;
			}
		}
	} else {
		if (verbose)
			ata_link_info(link,
	"no reset method available, skipping reset\n");
		if (!(lflags & ATA_LFLAG_ASSUME_CLASS))
			lflags |= ATA_LFLAG_ASSUME_ATA;
	}

	/*
	 * Post-reset processing
	 */
	ata_for_each_dev(dev, link, ALL) {
		/* After the reset, the device state is PIO 0 and the
		 * controller state is undefined.  Reset also wakes up
		 * drives from sleeping mode.
		 */
		dev->pio_mode = XFER_PIO_0;
		dev->flags &= ~ATA_DFLAG_SLEEPING;

		if (ata_phys_link_offline(ata_dev_phys_link(dev)))
			continue;

		/* apply class override */
		if (lflags & ATA_LFLAG_ASSUME_ATA)
			classes[dev->devno] = ATA_DEV_ATA;
		else if (lflags & ATA_LFLAG_ASSUME_SEMB)
			classes[dev->devno] = ATA_DEV_SEMB_UNSUP;
	}

	/* record current link speed */
	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
		link->sata_spd = (sstatus >> 4) & 0xf;
	if (slave && sata_scr_read(slave, SCR_STATUS, &sstatus) == 0)
		slave->sata_spd = (sstatus >> 4) & 0xf;

	/* thaw the port */
	if (ata_is_host_link(link))
		ata_eh_thaw_port(ap);

	/* postreset() should clear hardware SError.  Although SError
	 * is cleared during link resume, clearing SError here is
	 * necessary as some PHYs raise hotplug events after SRST.
	 * This introduces race condition where hotplug occurs between
	 * reset and here.  This race is mediated by cross checking
	 * link onlineness and classification result later.
	 */
	if (postreset) {
		postreset(link, classes);
		if (slave)
			postreset(slave, classes);
	}

	/*
	 * Some controllers can't be frozen very well and may set spurious
	 * error conditions during reset.  Clear accumulated error
	 * information and re-thaw the port if frozen.  As reset is the
	 * final recovery action and we cross check link onlineness against
	 * device classification later, no hotplug event is lost by this.
	 */
	spin_lock_irqsave(link->ap->lock, flags);
	memset(&link->eh_info, 0, sizeof(link->eh_info));
	if (slave)
		memset(&slave->eh_info, 0, sizeof(link->eh_info));
	ap->pflags &= ~ATA_PFLAG_EH_PENDING;
	spin_unlock_irqrestore(link->ap->lock, flags);

	if (ap->pflags & ATA_PFLAG_FROZEN)
		ata_eh_thaw_port(ap);

	/*
	 * Make sure onlineness and classification result correspond.
	 * Hotplug could have happened during reset and some
	 * controllers fail to wait while a drive is spinning up after
	 * being hotplugged causing misdetection.  By cross checking
	 * link on/offlineness and classification result, those
	 * conditions can be reliably detected and retried.
	 */
	nr_unknown = 0;
	ata_for_each_dev(dev, link, ALL) {
		if (ata_phys_link_online(ata_dev_phys_link(dev))) {
			if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
				ata_dev_dbg(dev, "link online but device misclassified\n");
				classes[dev->devno] = ATA_DEV_NONE;
				nr_unknown++;
			}
		} else if (ata_phys_link_offline(ata_dev_phys_link(dev))) {
			if (ata_class_enabled(classes[dev->devno]))
				ata_dev_dbg(dev,
					    "link offline, clearing class %d to NONE\n",
					    classes[dev->devno]);
			classes[dev->devno] = ATA_DEV_NONE;
		} else if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
			ata_dev_dbg(dev,
				    "link status unknown, clearing UNKNOWN to NONE\n");
			classes[dev->devno] = ATA_DEV_NONE;
		}
	}

	if (classify && nr_unknown) {
		if (try < max_tries) {
			ata_link_warn(link,
				      "link online but %d devices misclassified, retrying\n",
				      nr_unknown);
			failed_link = link;
			rc = -EAGAIN;
			goto fail;
		}
		ata_link_warn(link,
			      "link online but %d devices misclassified, "
			      "device detection might fail\n", nr_unknown);
	}

	/* reset successful, schedule revalidation */
	ata_eh_done(link, NULL, ATA_EH_RESET);
	if (slave)
		ata_eh_done(slave, NULL, ATA_EH_RESET);
	ehc->last_reset = jiffies;		/* update to completion time */
	ehc->i.action |= ATA_EH_REVALIDATE;
	link->lpm_policy = ATA_LPM_UNKNOWN;	/* reset LPM state */

	rc = 0;
 out:
	/* clear hotplug flag */
	ehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
	if (slave)
		sehc->i.flags &= ~ATA_EHI_HOTPLUGGED;

	spin_lock_irqsave(ap->lock, flags);
	ap->pflags &= ~ATA_PFLAG_RESETTING;
	spin_unlock_irqrestore(ap->lock, flags);

	return rc;

 fail:
	/* if SCR isn't accessible on a fan-out port, PMP needs to be reset */
	if (!ata_is_host_link(link) &&
	    sata_scr_read(link, SCR_STATUS, &sstatus))
		rc = -ERESTART;

	if (try >= max_tries) {
		/*
		 * Thaw host port even if reset failed, so that the port
		 * can be retried on the next phy event.  This risks
		 * repeated EH runs but seems to be a better tradeoff than
		 * shutting down a port after a botched hotplug attempt.
		 */
		if (ata_is_host_link(link))
			ata_eh_thaw_port(ap);
		goto out;
	}

	now = jiffies;
	if (time_before(now, deadline)) {
		unsigned long delta = deadline - now;

		ata_link_warn(failed_link,
			"reset failed (errno=%d), retrying in %u secs\n",
			rc, DIV_ROUND_UP(jiffies_to_msecs(delta), 1000));

		ata_eh_release(ap);
		while (delta)
			delta = schedule_timeout_uninterruptible(delta);
		ata_eh_acquire(ap);
	}

	/*
	 * While disks spinup behind PMP, some controllers fail sending SRST.
	 * They need to be reset - as well as the PMP - before retrying.
	 */
	if (rc == -ERESTART) {
		if (ata_is_host_link(link))
			ata_eh_thaw_port(ap);
		goto out;
	}

	if (try == max_tries - 1) {
		sata_down_spd_limit(link, 0);
		if (slave)
			sata_down_spd_limit(slave, 0);
	} else if (rc == -EPIPE)
		sata_down_spd_limit(failed_link, 0);

	if (hardreset)
		reset = hardreset;
	goto retry;
}

static inline void ata_eh_pull_park_action(struct ata_port *ap)
{
	struct ata_link *link;
	struct ata_device *dev;
	unsigned long flags;

	/*
	 * This function can be thought of as an extended version of
	 * ata_eh_about_to_do() specially crafted to accommodate the
	 * requirements of ATA_EH_PARK handling. Since the EH thread
	 * does not leave the do {} while () loop in ata_eh_recover as
	 * long as the timeout for a park request to *one* device on
	 * the port has not expired, and since we still want to pick
	 * up park requests to other devices on the same port or
	 * timeout updates for the same device, we have to pull
	 * ATA_EH_PARK actions from eh_info into eh_context.i
	 * ourselves at the beginning of each pass over the loop.
	 *
	 * Additionally, all write accesses to &ap->park_req_pending
	 * through reinit_completion() (see below) or complete_all()
	 * (see ata_scsi_park_store()) are protected by the host lock.
	 * As a result we have that park_req_pending.done is zero on
	 * exit from this function, i.e. when ATA_EH_PARK actions for
	 * *all* devices on port ap have been pulled into the
	 * respective eh_context structs. If, and only if,
	 * park_req_pending.done is non-zero by the time we reach
	 * wait_for_completion_timeout(), another ATA_EH_PARK action
	 * has been scheduled for at least one of the devices on port
	 * ap and we have to cycle over the do {} while () loop in
	 * ata_eh_recover() again.
	 */

	spin_lock_irqsave(ap->lock, flags);
	reinit_completion(&ap->park_req_pending);
	ata_for_each_link(link, ap, EDGE) {
		ata_for_each_dev(dev, link, ALL) {
			struct ata_eh_info *ehi = &link->eh_info;

			link->eh_context.i.dev_action[dev->devno] |=
				ehi->dev_action[dev->devno] & ATA_EH_PARK;
			ata_eh_clear_action(link, dev, ehi, ATA_EH_PARK);
		}
	}
	spin_unlock_irqrestore(ap->lock, flags);
}

static void ata_eh_park_issue_cmd(struct ata_device *dev, int park)
{
	struct ata_eh_context *ehc = &dev->link->eh_context;
	struct ata_taskfile tf;
	unsigned int err_mask;

	ata_tf_init(dev, &tf);
	if (park) {
		ehc->unloaded_mask |= 1 << dev->devno;
		tf.command = ATA_CMD_IDLEIMMEDIATE;
		tf.feature = 0x44;
		tf.lbal = 0x4c;
		tf.lbam = 0x4e;
		tf.lbah = 0x55;
	} else {
		ehc->unloaded_mask &= ~(1 << dev->devno);
		tf.command = ATA_CMD_CHK_POWER;
	}

	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
	tf.protocol = ATA_PROT_NODATA;
	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
	if (park && (err_mask || tf.lbal != 0xc4)) {
		ata_dev_err(dev, "head unload failed!\n");
		ehc->unloaded_mask &= ~(1 << dev->devno);
	}
}

static int ata_eh_revalidate_and_attach(struct ata_link *link,
					struct ata_device **r_failed_dev)
{
	struct ata_port *ap = link->ap;
	struct ata_eh_context *ehc = &link->eh_context;
	struct ata_device *dev;
	unsigned int new_mask = 0;
	unsigned long flags;
	int rc = 0;

	DPRINTK("ENTER\n");

	/* For PATA drive side cable detection to work, IDENTIFY must
	 * be done backwards such that PDIAG- is released by the slave
	 * device before the master device is identified.
	 */
	ata_for_each_dev(dev, link, ALL_REVERSE) {
		unsigned int action = ata_eh_dev_action(dev);
		unsigned int readid_flags = 0;

		if (ehc->i.flags & ATA_EHI_DID_RESET)
			readid_flags |= ATA_READID_POSTRESET;

		if ((action & ATA_EH_REVALIDATE) && ata_dev_enabled(dev)) {
			WARN_ON(dev->class == ATA_DEV_PMP);

			if (ata_phys_link_offline(ata_dev_phys_link(dev))) {
				rc = -EIO;
				goto err;
			}

			ata_eh_about_to_do(link, dev, ATA_EH_REVALIDATE);
			rc = ata_dev_revalidate(dev, ehc->classes[dev->devno],
						readid_flags);
			if (rc)
				goto err;

			ata_eh_done(link, dev, ATA_EH_REVALIDATE);

			/* Configuration may have changed, reconfigure
			 * transfer mode.
			 */
			ehc->i.flags |= ATA_EHI_SETMODE;

			/* schedule the scsi_rescan_device() here */
			schedule_work(&(ap->scsi_rescan_task));
		} else if (dev->class == ATA_DEV_UNKNOWN &&
			   ehc->tries[dev->devno] &&
			   ata_class_enabled(ehc->classes[dev->devno])) {
			/* Temporarily set dev->class, it will be
			 * permanently set once all configurations are
			 * complete.  This is necessary because new
			 * device configuration is done in two
			 * separate loops.
			 */
			dev->class = ehc->classes[dev->devno];

			if (dev->class == ATA_DEV_PMP)
				rc = sata_pmp_attach(dev);
			else
				rc = ata_dev_read_id(dev, &dev->class,
						     readid_flags, dev->id);

			/* read_id might have changed class, store and reset */
			ehc->classes[dev->devno] = dev->class;
			dev->class = ATA_DEV_UNKNOWN;

			switch (rc) {
			case 0:
				/* clear error info accumulated during probe */
				ata_ering_clear(&dev->ering);
				new_mask |= 1 << dev->devno;
				break;
			case -ENOENT:
				/* IDENTIFY was issued to non-existent
				 * device.  No need to reset.  Just
				 * thaw and ignore the device.
				 */
				ata_eh_thaw_port(ap);
				break;
			default:
				goto err;
			}
		}
	}

	/* PDIAG- should have been released, ask cable type if post-reset */
	if ((ehc->i.flags & ATA_EHI_DID_RESET) && ata_is_host_link(link)) {
		if (ap->ops->cable_detect)
			ap->cbl = ap->ops->cable_detect(ap);
		ata_force_cbl(ap);
	}

	/* Configure new devices forward such that user doesn't see
	 * device detection messages backwards.
	 */
	ata_for_each_dev(dev, link, ALL) {
		if (!(new_mask & (1 << dev->devno)))
			continue;

		dev->class = ehc->classes[dev->devno];

		if (dev->class == ATA_DEV_PMP)
			continue;

		ehc->i.flags |= ATA_EHI_PRINTINFO;
		rc = ata_dev_configure(dev);
		ehc->i.flags &= ~ATA_EHI_PRINTINFO;
		if (rc) {
			dev->class = ATA_DEV_UNKNOWN;
			goto err;
		}

		spin_lock_irqsave(ap->lock, flags);
		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
		spin_unlock_irqrestore(ap->lock, flags);

		/* new device discovered, configure xfermode */
		ehc->i.flags |= ATA_EHI_SETMODE;
	}

	return 0;

 err:
	*r_failed_dev = dev;
	DPRINTK("EXIT rc=%d\n", rc);
	return rc;
}

/**
 *	ata_set_mode - Program timings and issue SET FEATURES - XFER
 *	@link: link on which timings will be programmed
 *	@r_failed_dev: out parameter for failed device
 *
 *	Set ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
 *	ata_set_mode() fails, pointer to the failing device is
 *	returned in @r_failed_dev.
 *
 *	LOCKING:
 *	PCI/etc. bus probe sem.
 *
 *	RETURNS:
 *	0 on success, negative errno otherwise
 */
int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
{
	struct ata_port *ap = link->ap;
	struct ata_device *dev;
	int rc;

	/* if data transfer is verified, clear DUBIOUS_XFER on ering top */
	ata_for_each_dev(dev, link, ENABLED) {
		if (!(dev->flags & ATA_DFLAG_DUBIOUS_XFER)) {
			struct ata_ering_entry *ent;

			ent = ata_ering_top(&dev->ering);
			if (ent)
				ent->eflags &= ~ATA_EFLAG_DUBIOUS_XFER;
		}
	}

	/* has private set_mode? */
	if (ap->ops->set_mode)
		rc = ap->ops->set_mode(link, r_failed_dev);
	else
		rc = ata_do_set_mode(link, r_failed_dev);

	/* if transfer mode has changed, set DUBIOUS_XFER on device */
	ata_for_each_dev(dev, link, ENABLED) {
		struct ata_eh_context *ehc = &link->eh_context;
		u8 saved_xfer_mode = ehc->saved_xfer_mode[dev->devno];
		u8 saved_ncq = !!(ehc->saved_ncq_enabled & (1 << dev->devno));

		if (dev->xfer_mode != saved_xfer_mode ||
		    ata_ncq_enabled(dev) != saved_ncq)
			dev->flags |= ATA_DFLAG_DUBIOUS_XFER;
	}

	return rc;
}

/**
 *	atapi_eh_clear_ua - Clear ATAPI UNIT ATTENTION after reset
 *	@dev: ATAPI device to clear UA for
 *
 *	Resets and other operations can make an ATAPI device raise
 *	UNIT ATTENTION which causes the next operation to fail.  This
 *	function clears UA.
 *
 *	LOCKING:
 *	EH context (may sleep).
 *
 *	RETURNS:
 *	0 on success, -errno on failure.
 */
static int atapi_eh_clear_ua(struct ata_device *dev)
{
	int i;

	for (i = 0; i < ATA_EH_UA_TRIES; i++) {
		u8 *sense_buffer = dev->link->ap->sector_buf;
		u8 sense_key = 0;
		unsigned int err_mask;

		err_mask = atapi_eh_tur(dev, &sense_key);
		if (err_mask != 0 && err_mask != AC_ERR_DEV) {
			ata_dev_warn(dev,
				     "TEST_UNIT_READY failed (err_mask=0x%x)\n",
				     err_mask);
			return -EIO;
		}

		if (!err_mask || sense_key != UNIT_ATTENTION)
			return 0;

		err_mask = atapi_eh_request_sense(dev, sense_buffer, sense_key);
		if (err_mask) {
			ata_dev_warn(dev, "failed to clear "
				"UNIT ATTENTION (err_mask=0x%x)\n", err_mask);
			return -EIO;
		}
	}

	ata_dev_warn(dev, "UNIT ATTENTION persists after %d tries\n",
		     ATA_EH_UA_TRIES);

	return 0;
}

/**
 *	ata_eh_maybe_retry_flush - Retry FLUSH if necessary
 *	@dev: ATA device which may need FLUSH retry
 *
 *	If @dev failed FLUSH, it needs to be reported upper layer
 *	immediately as it means that @dev failed to remap and already
 *	lost at least a sector and further FLUSH retrials won't make
 *	any difference to the lost sector.  However, if FLUSH failed
 *	for other reasons, for example transmission error, FLUSH needs
 *	to be retried.
 *
 *	This function determines whether FLUSH failure retry is
 *	necessary and performs it if so.
 *
 *	RETURNS:
 *	0 if EH can continue, -errno if EH needs to be repeated.
 */
static int ata_eh_maybe_retry_flush(struct ata_device *dev)
{
	struct ata_link *link = dev->link;
	struct ata_port *ap = link->ap;
	struct ata_queued_cmd *qc;
	struct ata_taskfile tf;
	unsigned int err_mask;
	int rc = 0;

	/* did flush fail for this device? */
	if (!ata_tag_valid(link->active_tag))
		return 0;

	qc = __ata_qc_from_tag(ap, link->active_tag);
	if (qc->dev != dev || (qc->tf.command != ATA_CMD_FLUSH_EXT &&
			       qc->tf.command != ATA_CMD_FLUSH))
		return 0;

	/* if the device failed it, it should be reported to upper layers */
	if (qc->err_mask & AC_ERR_DEV)
		return 0;

	/* flush failed for some other reason, give it another shot */
	ata_tf_init(dev, &tf);

	tf.command = qc->tf.command;
	tf.flags |= ATA_TFLAG_DEVICE;
	tf.protocol = ATA_PROT_NODATA;

	ata_dev_warn(dev, "retrying FLUSH 0x%x Emask 0x%x\n",
		       tf.command, qc->err_mask);

	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
	if (!err_mask) {
		/*
		 * FLUSH is complete but there's no way to
		 * successfully complete a failed command from EH.
		 * Making sure retry is allowed at least once and
		 * retrying it should do the trick - whatever was in
		 * the cache is already on the platter and this won't
		 * cause infinite loop.
		 */
		qc->scsicmd->allowed = max(qc->scsicmd->allowed, 1);
	} else {
		ata_dev_warn(dev, "FLUSH failed Emask 0x%x\n",
			       err_mask);
		rc = -EIO;

		/* if device failed it, report it to upper layers */
		if (err_mask & AC_ERR_DEV) {
			qc->err_mask |= AC_ERR_DEV;
			qc->result_tf = tf;
			if (!(ap->pflags & ATA_PFLAG_FROZEN))
				rc = 0;
		}
	}
	return rc;
}

/**
 *	ata_eh_set_lpm - configure SATA interface power management
 *	@link: link to configure power management
 *	@policy: the link power management policy
 *	@r_failed_dev: out parameter for failed device
 *
 *	Enable SATA Interface power management.  This will enable
 *	Device Interface Power Management (DIPM) for min_power
 * 	policy, and then call driver specific callbacks for
 *	enabling Host Initiated Power management.
 *
 *	LOCKING:
 *	EH context.
 *
 *	RETURNS:
 *	0 on success, -errno on failure.
 */
static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
			  struct ata_device **r_failed_dev)
{
	struct ata_port *ap = ata_is_host_link(link) ? link->ap : NULL;
	struct ata_eh_context *ehc = &link->eh_context;
	struct ata_device *dev, *link_dev = NULL, *lpm_dev = NULL;
	enum ata_lpm_policy old_policy = link->lpm_policy;
	bool no_dipm = link->ap->flags & ATA_FLAG_NO_DIPM;
	unsigned int hints = ATA_LPM_EMPTY | ATA_LPM_HIPM;
	unsigned int err_mask;
	int rc;

	/* if the link or host doesn't do LPM, noop */
	if ((link->flags & ATA_LFLAG_NO_LPM) || (ap && !ap->ops->set_lpm))
		return 0;

	/*
	 * DIPM is enabled only for MIN_POWER as some devices
	 * misbehave when the host NACKs transition to SLUMBER.  Order
	 * device and link configurations such that the host always
	 * allows DIPM requests.
	 */
	ata_for_each_dev(dev, link, ENABLED) {
		bool hipm = ata_id_has_hipm(dev->id);
		bool dipm = ata_id_has_dipm(dev->id) && !no_dipm;

		/* find the first enabled and LPM enabled devices */
		if (!link_dev)
			link_dev = dev;

		if (!lpm_dev && (hipm || dipm))
			lpm_dev = dev;

		hints &= ~ATA_LPM_EMPTY;
		if (!hipm)
			hints &= ~ATA_LPM_HIPM;

		/* disable DIPM before changing link config */
		if (policy != ATA_LPM_MIN_POWER && dipm) {
			err_mask = ata_dev_set_feature(dev,
					SETFEATURES_SATA_DISABLE, SATA_DIPM);
			if (err_mask && err_mask != AC_ERR_DEV) {
				ata_dev_warn(dev,
					     "failed to disable DIPM, Emask 0x%x\n",
					     err_mask);
				rc = -EIO;
				goto fail;
			}
		}
	}

	if (ap) {
		rc = ap->ops->set_lpm(link, policy, hints);
		if (!rc && ap->slave_link)
			rc = ap->ops->set_lpm(ap->slave_link, policy, hints);
	} else
		rc = sata_pmp_set_lpm(link, policy, hints);

	/*
	 * Attribute link config failure to the first (LPM) enabled
	 * device on the link.
	 */
	if (rc) {
		if (rc == -EOPNOTSUPP) {
			link->flags |= ATA_LFLAG_NO_LPM;
			return 0;
		}
		dev = lpm_dev ? lpm_dev : link_dev;
		goto fail;
	}

	/*
	 * Low level driver acked the transition.  Issue DIPM command
	 * with the new policy set.
	 */
	link->lpm_policy = policy;
	if (ap && ap->slave_link)
		ap->slave_link->lpm_policy = policy;

	/* host config updated, enable DIPM if transitioning to MIN_POWER */
	ata_for_each_dev(dev, link, ENABLED) {
		if (policy == ATA_LPM_MIN_POWER && !no_dipm &&
		    ata_id_has_dipm(dev->id)) {
			err_mask = ata_dev_set_feature(dev,
					SETFEATURES_SATA_ENABLE, SATA_DIPM);
			if (err_mask && err_mask != AC_ERR_DEV) {
				ata_dev_warn(dev,
					"failed to enable DIPM, Emask 0x%x\n",
					err_mask);
				rc = -EIO;
				goto fail;
			}
		}
	}

	link->last_lpm_change = jiffies;
	link->flags |= ATA_LFLAG_CHANGED;

	return 0;

fail:
	/* restore the old policy */
	link->lpm_policy = old_policy;
	if (ap && ap->slave_link)
		ap->slave_link->lpm_policy = old_policy;

	/* if no device or only one more chance is left, disable LPM */
	if (!dev || ehc->tries[dev->devno] <= 2) {
		ata_link_warn(link, "disabling LPM on the link\n");
		link->flags |= ATA_LFLAG_NO_LPM;
	}
	if (r_failed_dev)
		*r_failed_dev = dev;
	return rc;
}

int ata_link_nr_enabled(struct ata_link *link)
{
	struct ata_device *dev;
	int cnt = 0;

	ata_for_each_dev(dev, link, ENABLED)
		cnt++;
	return cnt;
}

static int ata_link_nr_vacant(struct ata_link *link)
{
	struct ata_device *dev;
	int cnt = 0;

	ata_for_each_dev(dev, link, ALL)
		if (dev->class == ATA_DEV_UNKNOWN)
			cnt++;
	return cnt;
}

static int ata_eh_skip_recovery(struct ata_link *link)
{
	struct ata_port *ap = link->ap;
	struct ata_eh_context *ehc = &link->eh_context;
	struct ata_device *dev;

	/* skip disabled links */
	if (link->flags & ATA_LFLAG_DISABLED)
		return 1;

	/* skip if explicitly requested */
	if (ehc->i.flags & ATA_EHI_NO_RECOVERY)
		return 1;

	/* thaw frozen port and recover failed devices */
	if ((ap->pflags & ATA_PFLAG_FROZEN) || ata_link_nr_enabled(link))
		return 0;

	/* reset at least once if reset is requested */
	if ((ehc->i.action & ATA_EH_RESET) &&
	    !(ehc->i.flags & ATA_EHI_DID_RESET))
		return 0;

	/* skip if class codes for all vacant slots are ATA_DEV_NONE */
	ata_for_each_dev(dev, link, ALL) {
		if (dev->class == ATA_DEV_UNKNOWN &&
		    ehc->classes[dev->devno] != ATA_DEV_NONE)
			return 0;
	}

	return 1;
}

static int ata_count_probe_trials_cb(struct ata_ering_entry *ent, void *void_arg)
{
	u64 interval = msecs_to_jiffies(ATA_EH_PROBE_TRIAL_INTERVAL);
	u64 now = get_jiffies_64();
	int *trials = void_arg;

	if ((ent->eflags & ATA_EFLAG_OLD_ER) ||
	    (ent->timestamp < now - min(now, interval)))
		return -1;

	(*trials)++;
	return 0;
}

static int ata_eh_schedule_probe(struct ata_device *dev)
{
	struct ata_eh_context *ehc = &dev->link->eh_context;
	struct ata_link *link = ata_dev_phys_link(dev);
	int trials = 0;

	if (!(ehc->i.probe_mask & (1 << dev->devno)) ||
	    (ehc->did_probe_mask & (1 << dev->devno)))
		return 0;

	ata_eh_detach_dev(dev);
	ata_dev_init(dev);
	ehc->did_probe_mask |= (1 << dev->devno);
	ehc->i.action |= ATA_EH_RESET;
	ehc->saved_xfer_mode[dev->devno] = 0;
	ehc->saved_ncq_enabled &= ~(1 << dev->devno);

	/* the link maybe in a deep sleep, wake it up */
	if (link->lpm_policy > ATA_LPM_MAX_POWER) {
		if (ata_is_host_link(link))
			link->ap->ops->set_lpm(link, ATA_LPM_MAX_POWER,
					       ATA_LPM_EMPTY);
		else
			sata_pmp_set_lpm(link, ATA_LPM_MAX_POWER,
					 ATA_LPM_EMPTY);
	}

	/* Record and count probe trials on the ering.  The specific
	 * error mask used is irrelevant.  Because a successful device
	 * detection clears the ering, this count accumulates only if
	 * there are consecutive failed probes.
	 *
	 * If the count is equal to or higher than ATA_EH_PROBE_TRIALS
	 * in the last ATA_EH_PROBE_TRIAL_INTERVAL, link speed is
	 * forced to 1.5Gbps.
	 *
	 * This is to work around cases where failed link speed
	 * negotiation results in device misdetection leading to
	 * infinite DEVXCHG or PHRDY CHG events.
	 */
	ata_ering_record(&dev->ering, 0, AC_ERR_OTHER);
	ata_ering_map(&dev->ering, ata_count_probe_trials_cb, &trials);

	if (trials > ATA_EH_PROBE_TRIALS)
		sata_down_spd_limit(link, 1);

	return 1;
}

static int ata_eh_handle_dev_fail(struct ata_device *dev, int err)
{
	struct ata_eh_context *ehc = &dev->link->eh_context;

	/* -EAGAIN from EH routine indicates retry without prejudice.
	 * The requester is responsible for ensuring forward progress.
	 */
	if (err != -EAGAIN)
		ehc->tries[dev->devno]--;

	switch (err) {
	case -ENODEV:
		/* device missing or wrong IDENTIFY data, schedule probing */
		ehc->i.probe_mask |= (1 << dev->devno);
	case -EINVAL:
		/* give it just one more chance */
		ehc->tries[dev->devno] = min(ehc->tries[dev->devno], 1);
	case -EIO:
		if (ehc->tries[dev->devno] == 1) {
			/* This is the last chance, better to slow
			 * down than lose it.
			 */
			sata_down_spd_limit(ata_dev_phys_link(dev), 0);
			if (dev->pio_mode > XFER_PIO_0)
				ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
		}
	}

	if (ata_dev_enabled(dev) && !ehc->tries[dev->devno]) {
		/* disable device if it has used up all its chances */
		ata_dev_disable(dev);

		/* detach if offline */
		if (ata_phys_link_offline(ata_dev_phys_link(dev)))
			ata_eh_detach_dev(dev);

		/* schedule probe if necessary */
		if (ata_eh_schedule_probe(dev)) {
			ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
			memset(ehc->cmd_timeout_idx[dev->devno], 0,
			       sizeof(ehc->cmd_timeout_idx[dev->devno]));
		}

		return 1;
	} else {
		ehc->i.action |= ATA_EH_RESET;
		return 0;
	}
}

/**
 *	ata_eh_recover - recover host port after error
 *	@ap: host port to recover
 *	@prereset: prereset method (can be NULL)
 *	@softreset: softreset method (can be NULL)
 *	@hardreset: hardreset method (can be NULL)
 *	@postreset: postreset method (can be NULL)
 *	@r_failed_link: out parameter for failed link
 *
 *	This is the alpha and omega, eum and yang, heart and soul of
 *	libata exception handling.  On entry, actions required to
 *	recover each link and hotplug requests are recorded in the
 *	link's eh_context.  This function executes all the operations
 *	with appropriate retrials and fallbacks to resurrect failed
 *	devices, detach goners and greet newcomers.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	0 on success, -errno on failure.
 */
int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
		   ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
		   ata_postreset_fn_t postreset,
		   struct ata_link **r_failed_link)
{
	struct ata_link *link;
	struct ata_device *dev;
	int rc, nr_fails;
	unsigned long flags, deadline;

	DPRINTK("ENTER\n");

	/* prep for recovery */
	ata_for_each_link(link, ap, EDGE) {
		struct ata_eh_context *ehc = &link->eh_context;

		/* re-enable link? */
		if (ehc->i.action & ATA_EH_ENABLE_LINK) {
			ata_eh_about_to_do(link, NULL, ATA_EH_ENABLE_LINK);
			spin_lock_irqsave(ap->lock, flags);
			link->flags &= ~ATA_LFLAG_DISABLED;
			spin_unlock_irqrestore(ap->lock, flags);
			ata_eh_done(link, NULL, ATA_EH_ENABLE_LINK);
		}

		ata_for_each_dev(dev, link, ALL) {
			if (link->flags & ATA_LFLAG_NO_RETRY)
				ehc->tries[dev->devno] = 1;
			else
				ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;

			/* collect port action mask recorded in dev actions */
			ehc->i.action |= ehc->i.dev_action[dev->devno] &
					 ~ATA_EH_PERDEV_MASK;
			ehc->i.dev_action[dev->devno] &= ATA_EH_PERDEV_MASK;

			/* process hotplug request */
			if (dev->flags & ATA_DFLAG_DETACH)
				ata_eh_detach_dev(dev);

			/* schedule probe if necessary */
			if (!ata_dev_enabled(dev))
				ata_eh_schedule_probe(dev);
		}
	}

 retry:
	rc = 0;

	/* if UNLOADING, finish immediately */
	if (ap->pflags & ATA_PFLAG_UNLOADING)
		goto out;

	/* prep for EH */
	ata_for_each_link(link, ap, EDGE) {
		struct ata_eh_context *ehc = &link->eh_context;

		/* skip EH if possible. */
		if (ata_eh_skip_recovery(link))
			ehc->i.action = 0;

		ata_for_each_dev(dev, link, ALL)
			ehc->classes[dev->devno] = ATA_DEV_UNKNOWN;
	}

	/* reset */
	ata_for_each_link(link, ap, EDGE) {
		struct ata_eh_context *ehc = &link->eh_context;

		if (!(ehc->i.action & ATA_EH_RESET))
			continue;

		rc = ata_eh_reset(link, ata_link_nr_vacant(link),
				  prereset, softreset, hardreset, postreset);
		if (rc) {
			ata_link_err(link, "reset failed, giving up\n");
			goto out;
		}
	}

	do {
		unsigned long now;

		/*
		 * clears ATA_EH_PARK in eh_info and resets
		 * ap->park_req_pending
		 */
		ata_eh_pull_park_action(ap);

		deadline = jiffies;
		ata_for_each_link(link, ap, EDGE) {
			ata_for_each_dev(dev, link, ALL) {
				struct ata_eh_context *ehc = &link->eh_context;
				unsigned long tmp;

				if (dev->class != ATA_DEV_ATA &&
				    dev->class != ATA_DEV_ZAC)
					continue;
				if (!(ehc->i.dev_action[dev->devno] &
				      ATA_EH_PARK))
					continue;
				tmp = dev->unpark_deadline;
				if (time_before(deadline, tmp))
					deadline = tmp;
				else if (time_before_eq(tmp, jiffies))
					continue;
				if (ehc->unloaded_mask & (1 << dev->devno))
					continue;

				ata_eh_park_issue_cmd(dev, 1);
			}
		}

		now = jiffies;
		if (time_before_eq(deadline, now))
			break;

		ata_eh_release(ap);
		deadline = wait_for_completion_timeout(&ap->park_req_pending,
						       deadline - now);
		ata_eh_acquire(ap);
	} while (deadline);
	ata_for_each_link(link, ap, EDGE) {
		ata_for_each_dev(dev, link, ALL) {
			if (!(link->eh_context.unloaded_mask &
			      (1 << dev->devno)))
				continue;

			ata_eh_park_issue_cmd(dev, 0);
			ata_eh_done(link, dev, ATA_EH_PARK);
		}
	}

	/* the rest */
	nr_fails = 0;
	ata_for_each_link(link, ap, PMP_FIRST) {
		struct ata_eh_context *ehc = &link->eh_context;

		if (sata_pmp_attached(ap) && ata_is_host_link(link))
			goto config_lpm;

		/* revalidate existing devices and attach new ones */
		rc = ata_eh_revalidate_and_attach(link, &dev);
		if (rc)
			goto rest_fail;

		/* if PMP got attached, return, pmp EH will take care of it */
		if (link->device->class == ATA_DEV_PMP) {
			ehc->i.action = 0;
			return 0;
		}

		/* configure transfer mode if necessary */
		if (ehc->i.flags & ATA_EHI_SETMODE) {
			rc = ata_set_mode(link, &dev);
			if (rc)
				goto rest_fail;
			ehc->i.flags &= ~ATA_EHI_SETMODE;
		}

		/* If reset has been issued, clear UA to avoid
		 * disrupting the current users of the device.
		 */
		if (ehc->i.flags & ATA_EHI_DID_RESET) {
			ata_for_each_dev(dev, link, ALL) {
				if (dev->class != ATA_DEV_ATAPI)
					continue;
				rc = atapi_eh_clear_ua(dev);
				if (rc)
					goto rest_fail;
				if (zpodd_dev_enabled(dev))
					zpodd_post_poweron(dev);
			}
		}

		/* retry flush if necessary */
		ata_for_each_dev(dev, link, ALL) {
			if (dev->class != ATA_DEV_ATA &&
			    dev->class != ATA_DEV_ZAC)
				continue;
			rc = ata_eh_maybe_retry_flush(dev);
			if (rc)
				goto rest_fail;
		}

	config_lpm:
		/* configure link power saving */
		if (link->lpm_policy != ap->target_lpm_policy) {
			rc = ata_eh_set_lpm(link, ap->target_lpm_policy, &dev);
			if (rc)
				goto rest_fail;
		}

		/* this link is okay now */
		ehc->i.flags = 0;
		continue;

	rest_fail:
		nr_fails++;
		if (dev)
			ata_eh_handle_dev_fail(dev, rc);

		if (ap->pflags & ATA_PFLAG_FROZEN) {
			/* PMP reset requires working host port.
			 * Can't retry if it's frozen.
			 */
			if (sata_pmp_attached(ap))
				goto out;
			break;
		}
	}

	if (nr_fails)
		goto retry;

 out:
	if (rc && r_failed_link)
		*r_failed_link = link;

	DPRINTK("EXIT, rc=%d\n", rc);
	return rc;
}

/**
 *	ata_eh_finish - finish up EH
 *	@ap: host port to finish EH for
 *
 *	Recovery is complete.  Clean up EH states and retry or finish
 *	failed qcs.
 *
 *	LOCKING:
 *	None.
 */
void ata_eh_finish(struct ata_port *ap)
{
	int tag;

	/* retry or finish qcs */
	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);

		if (!(qc->flags & ATA_QCFLAG_FAILED))
			continue;

		if (qc->err_mask) {
			/* FIXME: Once EH migration is complete,
			 * generate sense data in this function,
			 * considering both err_mask and tf.
			 */
			if (qc->flags & ATA_QCFLAG_RETRY)
				ata_eh_qc_retry(qc);
			else
				ata_eh_qc_complete(qc);
		} else {
			if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
				ata_eh_qc_complete(qc);
			} else {
				/* feed zero TF to sense generation */
				memset(&qc->result_tf, 0, sizeof(qc->result_tf));
				ata_eh_qc_retry(qc);
			}
		}
	}

	/* make sure nr_active_links is zero after EH */
	WARN_ON(ap->nr_active_links);
	ap->nr_active_links = 0;
}

/**
 *	ata_do_eh - do standard error handling
 *	@ap: host port to handle error for
 *
 *	@prereset: prereset method (can be NULL)
 *	@softreset: softreset method (can be NULL)
 *	@hardreset: hardreset method (can be NULL)
 *	@postreset: postreset method (can be NULL)
 *
 *	Perform standard error handling sequence.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
	       ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
	       ata_postreset_fn_t postreset)
{
	struct ata_device *dev;
	int rc;

	ata_eh_autopsy(ap);
	ata_eh_report(ap);

	rc = ata_eh_recover(ap, prereset, softreset, hardreset, postreset,
			    NULL);
	if (rc) {
		ata_for_each_dev(dev, &ap->link, ALL)
			ata_dev_disable(dev);
	}

	ata_eh_finish(ap);
}

/**
 *	ata_std_error_handler - standard error handler
 *	@ap: host port to handle error for
 *
 *	Standard error handler
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
void ata_std_error_handler(struct ata_port *ap)
{
	struct ata_port_operations *ops = ap->ops;
	ata_reset_fn_t hardreset = ops->hardreset;

	/* ignore built-in hardreset if SCR access is not available */
	if (hardreset == sata_std_hardreset && !sata_scr_valid(&ap->link))
		hardreset = NULL;

	ata_do_eh(ap, ops->prereset, ops->softreset, hardreset, ops->postreset);
}

#ifdef CONFIG_PM
/**
 *	ata_eh_handle_port_suspend - perform port suspend operation
 *	@ap: port to suspend
 *
 *	Suspend @ap.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
static void ata_eh_handle_port_suspend(struct ata_port *ap)
{
	unsigned long flags;
	int rc = 0;
	struct ata_device *dev;

	/* are we suspending? */
	spin_lock_irqsave(ap->lock, flags);
	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
	    ap->pm_mesg.event & PM_EVENT_RESUME) {
		spin_unlock_irqrestore(ap->lock, flags);
		return;
	}
	spin_unlock_irqrestore(ap->lock, flags);

	WARN_ON(ap->pflags & ATA_PFLAG_SUSPENDED);

	/*
	 * If we have a ZPODD attached, check its zero
	 * power ready status before the port is frozen.
	 * Only needed for runtime suspend.
	 */
	if (PMSG_IS_AUTO(ap->pm_mesg)) {
		ata_for_each_dev(dev, &ap->link, ENABLED) {
			if (zpodd_dev_enabled(dev))
				zpodd_on_suspend(dev);
		}
	}

	/* tell ACPI we're suspending */
	rc = ata_acpi_on_suspend(ap);
	if (rc)
		goto out;

	/* suspend */
	ata_eh_freeze_port(ap);

	if (ap->ops->port_suspend)
		rc = ap->ops->port_suspend(ap, ap->pm_mesg);

	ata_acpi_set_state(ap, ap->pm_mesg);
 out:
	/* update the flags */
	spin_lock_irqsave(ap->lock, flags);

	ap->pflags &= ~ATA_PFLAG_PM_PENDING;
	if (rc == 0)
		ap->pflags |= ATA_PFLAG_SUSPENDED;
	else if (ap->pflags & ATA_PFLAG_FROZEN)
		ata_port_schedule_eh(ap);

	spin_unlock_irqrestore(ap->lock, flags);

	return;
}

/**
 *	ata_eh_handle_port_resume - perform port resume operation
 *	@ap: port to resume
 *
 *	Resume @ap.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
static void ata_eh_handle_port_resume(struct ata_port *ap)
{
	struct ata_link *link;
	struct ata_device *dev;
	unsigned long flags;
	int rc = 0;

	/* are we resuming? */
	spin_lock_irqsave(ap->lock, flags);
	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
	    !(ap->pm_mesg.event & PM_EVENT_RESUME)) {
		spin_unlock_irqrestore(ap->lock, flags);
		return;
	}
	spin_unlock_irqrestore(ap->lock, flags);

	WARN_ON(!(ap->pflags & ATA_PFLAG_SUSPENDED));

	/*
	 * Error timestamps are in jiffies which doesn't run while
	 * suspended and PHY events during resume isn't too uncommon.
	 * When the two are combined, it can lead to unnecessary speed
	 * downs if the machine is suspended and resumed repeatedly.
	 * Clear error history.
	 */
	ata_for_each_link(link, ap, HOST_FIRST)
		ata_for_each_dev(dev, link, ALL)
			ata_ering_clear(&dev->ering);

	ata_acpi_set_state(ap, ap->pm_mesg);

	if (ap->ops->port_resume)
		rc = ap->ops->port_resume(ap);

	/* tell ACPI that we're resuming */
	ata_acpi_on_resume(ap);

	/* update the flags */
	spin_lock_irqsave(ap->lock, flags);
	ap->pflags &= ~(ATA_PFLAG_PM_PENDING | ATA_PFLAG_SUSPENDED);
	spin_unlock_irqrestore(ap->lock, flags);
}
#endif /* CONFIG_PM */