usb: ehci-omap: Reset the USB Host OMAP module

In commit bb1f327 we removed the UHH reset to fix NFS root (over usb ethernet) problems with Beagleboard (3530 ES1.0). However, this seems to cause USB detection problems for Pandaboard, about (3/8). On further investigation, it seems that doing the UHH reset is not the cause of the original Beagleboard problem, but in the way the reset was done. This patch adds proper UHH RESET mechanism for OMAP3 and OMAP4/5 based on the UHH_REVISION register. This should fix the Beagleboard NFS problem as well as the Pandaboard USB detection problem. Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com> CC: Stefan Roese <sr@denx.de> Reviewed-by: Stefan Roese <sr@denx.de> Signed-off-by: Roger Quadros <rogerq@ti.com>

usb: ehci-omap: Reset the USB Host OMAP module
In commit bb1f327 we removed the UHH reset to fix NFS root (over usb ethernet) problems with Beagleboard (3530 ES1.0). However, this seems to cause USB detection problems for Pandaboard, about (3/8). On further investigation, it seems that doing the UHH reset is not the cause of the original Beagleboard problem, but in the way the reset was done. This patch adds proper UHH RESET mechanism for OMAP3 and OMAP4/5 based on the UHH_REVISION register. This should fix the Beagleboard NFS problem as well as the Pandaboard USB detection problem. Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com> CC: Stefan Roese <sr@denx.de> Reviewed-by: Stefan Roese <sr@denx.de> Signed-off-by: Roger Quadros <rogerq@ti.com>
Roger Quadros · Tom Rini
1 parent f33b9bd398
Showing 1 changed file with 42 additions and 15 deletions Side-by-side Diff
drivers/usb/host/ehci-omap.c
@@ -28,21 +28,48 @@
  
 static int omap_uhh_reset(void)
 {
-/*
- * Soft resetting the UHH module causes instability issues on
- * all OMAPs so we just avoid it.
- *
- * See OMAP36xx Errata
- *  i571: USB host EHCI may stall when entering smart-standby mode
- *  i660: USBHOST Configured In Smart-Idle Can Lead To a Deadlock
- *
- * On OMAP4/5, soft-resetting the UHH module will put it into
- * Smart-Idle mode and lead to a deadlock.
- *
- * On OMAP3, this doesn't seem to be the case but still instabilities
- * are observed on beagle (3530 ES1.0) if soft-reset is used.
- * e.g. NFS root failures with Linux kernel.
- */
+	int timeout = 0;
+	u32 rev;
+
+	rev = readl(&uhh->rev);
+
+	/* Soft RESET */
+	writel(OMAP_UHH_SYSCONFIG_SOFTRESET, &uhh->sysc);
+
+	switch (rev) {
+	case OMAP_USBHS_REV1:
+		/* Wait for soft RESET to complete */
+		while (!(readl(&uhh->syss) & 0x1)) {
+			if (timeout > 100) {
+				printf("%s: RESET timeout\n", __func__);
+				return -1;
+			}
+			udelay(10);
+			timeout++;
+		}
+
+		/* Set No-Idle, No-Standby */
+		writel(OMAP_UHH_SYSCONFIG_VAL, &uhh->sysc);
+		break;
+
+	default:	/* Rev. 2 onwards */
+
+		udelay(2); /* Need to wait before accessing SYSCONFIG back */
+
+		/* Wait for soft RESET to complete */
+		while ((readl(&uhh->sysc) & 0x1)) {
+			if (timeout > 100) {
+				printf("%s: RESET timeout\n", __func__);
+				return -1;
+			}
+			udelay(10);
+			timeout++;
+		}
+
+		writel(OMAP_UHH_SYSCONFIG_VAL, &uhh->sysc);
+		break;
+	}
+
 	return 0;
 }
...	...	@@ -28,21 +28,48 @@
28	28
29	29	static int omap_uhh_reset(void)
30	30	{
31		-/*
32		- * Soft resetting the UHH module causes instability issues on
33		- * all OMAPs so we just avoid it.
34		- *
35		- * See OMAP36xx Errata
36		- * i571: USB host EHCI may stall when entering smart-standby mode
37		- * i660: USBHOST Configured In Smart-Idle Can Lead To a Deadlock
38		- *
39		- * On OMAP4/5, soft-resetting the UHH module will put it into
40		- * Smart-Idle mode and lead to a deadlock.
41		- *
42		- * On OMAP3, this doesn't seem to be the case but still instabilities
43		- * are observed on beagle (3530 ES1.0) if soft-reset is used.
44		- * e.g. NFS root failures with Linux kernel.
45		- */
	31	+ int timeout = 0;
	32	+ u32 rev;
	33	+
	34	+ rev = readl(&uhh->rev);
	35	+
	36	+ /* Soft RESET */
	37	+ writel(OMAP_UHH_SYSCONFIG_SOFTRESET, &uhh->sysc);
	38	+
	39	+ switch (rev) {
	40	+ case OMAP_USBHS_REV1:
	41	+ /* Wait for soft RESET to complete */
	42	+ while (!(readl(&uhh->syss) & 0x1)) {
	43	+ if (timeout > 100) {
	44	+ printf("%s: RESET timeout\n", __func__);
	45	+ return -1;
	46	+ }
	47	+ udelay(10);
	48	+ timeout++;
	49	+ }
	50	+
	51	+ /* Set No-Idle, No-Standby */
	52	+ writel(OMAP_UHH_SYSCONFIG_VAL, &uhh->sysc);
	53	+ break;
	54	+
	55	+ default: /* Rev. 2 onwards */
	56	+
	57	+ udelay(2); /* Need to wait before accessing SYSCONFIG back */
	58	+
	59	+ /* Wait for soft RESET to complete */
	60	+ while ((readl(&uhh->sysc) & 0x1)) {
	61	+ if (timeout > 100) {
	62	+ printf("%s: RESET timeout\n", __func__);
	63	+ return -1;
	64	+ }
	65	+ udelay(10);
	66	+ timeout++;
	67	+ }
	68	+
	69	+ writel(OMAP_UHH_SYSCONFIG_VAL, &uhh->sysc);
	70	+ break;
	71	+ }
	72	+
46	73	return 0;
47	74	}
48	75