Blackfin: nand: drain the write buffer before returning

The current Blackfin nand write function fills up the write buffer but returns before it has had a chance to drain. On faster systems, this isn't a problem as the operation finishes before the ECC registers are read, but on slower systems the ECC may be incomplete when the core tries to read it. So wait for the buffer to drain once we're done writing to it. Signed-off-by: Andrew Caldwell <Andrew.Caldwell@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Blackfin: nand: drain the write buffer before returning
The current Blackfin nand write function fills up the write buffer but returns before it has had a chance to drain. On faster systems, this isn't a problem as the operation finishes before the ECC registers are read, but on slower systems the ECC may be incomplete when the core tries to read it. So wait for the buffer to drain once we're done writing to it. Signed-off-by: Andrew Caldwell <Andrew.Caldwell@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Andrew Caldwell · Scott Wood
1 parent 01f03bda5b
Showing 1 changed file with 6 additions and 1 deletions Side-by-side Diff
drivers/mtd/nand/bfin_nand.c
@@ -75,7 +75,7 @@
 int bfin_nfc_devready(struct mtd_info *mtd)
 {
 	pr_stamp();
-	return (bfin_read_NFC_STAT() & NBUSY ? 1 : 0);
+	return (bfin_read_NFC_STAT() & NBUSY) ? 1 : 0;
 }
  
 /*
@@ -132,6 +132,11 @@
  
 		bfin_write_NFC_DATA_WR(buf[i]);
 	}
+
+	/* Wait for the buffer to drain before we return */
+	while (!(bfin_read_NFC_STAT() & WB_EMPTY))
+		if (ctrlc())
+			return;
 }
  
 /*
...	...	@@ -75,7 +75,7 @@
75	75	int bfin_nfc_devready(struct mtd_info *mtd)
76	76	{
77	77	pr_stamp();
78		- return (bfin_read_NFC_STAT() & NBUSY ? 1 : 0);
	78	+ return (bfin_read_NFC_STAT() & NBUSY) ? 1 : 0;
79	79	}
80	80
81	81	/*
...	...	@@ -132,6 +132,11 @@
132	132
133	133	bfin_write_NFC_DATA_WR(buf[i]);
134	134	}
	135	+
	136	+ /* Wait for the buffer to drain before we return */
	137	+ while (!(bfin_read_NFC_STAT() & WB_EMPTY))
	138	+ if (ctrlc())
	139	+ return;
135	140	}
136	141
137	142	/*