This patch (as1549) fixes a rare problem affecting at least one OHCI
controller: The controller requires a delay of at least 1 microsecond
following a reset, even though it says that it is ready immediately.
The fix is to do the delay first, before checking whether the reset is
complete in the retry loop.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-by: Calin Demian <c.demian20@xxxxxxxxx>
CC: <stable@xxxxxxxxxxxxxxx>
---
drivers/usb/host/pci-quirks.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
Index: usb-3.4/drivers/usb/host/pci-quirks.c
===================================================================
--- usb-3.4.orig/drivers/usb/host/pci-quirks.c
+++ usb-3.4/drivers/usb/host/pci-quirks.c
@@ -520,9 +520,10 @@ static void __devinit quirk_usb_handoff_
/* reset requires max 10 us delay */
for (cnt = 30; cnt > 0; --cnt) { /* ... allow extra time */
+ /* Some controllers enable HCR too soon, so always delay some */
+ udelay(1);
if ((readl(base + OHCI_CMDSTATUS) & OHCI_HCR) == 0)
break;
- udelay(1);
}
writel(fminterval, base + OHCI_FMINTERVAL);
--
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