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path: root/drivers/usb/host/ehci-omap.c
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Diffstat (limited to 'drivers/usb/host/ehci-omap.c')
-rw-r--r--drivers/usb/host/ehci-omap.c57
1 files changed, 42 insertions, 15 deletions
diff --git a/drivers/usb/host/ehci-omap.c b/drivers/usb/host/ehci-omap.c
index c4ce487087..1b215c25f6 100644
--- a/drivers/usb/host/ehci-omap.c
+++ b/drivers/usb/host/ehci-omap.c
@@ -28,21 +28,48 @@ static struct omap_ehci *const ehci = (struct omap_ehci *)OMAP_EHCI_BASE;
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;
}