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Subject[PATCH] EHCI: add delay to bus_resume before accessing ports
This patch (as870) adds a delay to ehci-hcd's bus_resume routine.
Apparently there are controllers and/or BIOSes out there which need
such a delay to get the ports back into their correct state. This
fixes Bugzilla #8190.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>

---

This is for 2.6.20-stable. Earlier kernels aren't so eager to suspend
EHCI buses and so don't need this fix.


Index: 2.6.20/drivers/usb/host/ehci-hub.c
===================================================================
--- 2.6.20.orig/drivers/usb/host/ehci-hub.c
+++ 2.6.20/drivers/usb/host/ehci-hub.c
@@ -134,6 +134,10 @@ static int ehci_bus_resume (struct usb_h
/* restore CMD_RUN, framelist size, and irq threshold */
writel (ehci->command, &ehci->regs->command);

+ /* Some controller/firmware combinations need a delay during which
+ * they set up the port statuses. See Bugzilla #8190. */
+ mdelay(8);
+
/* manually resume the ports we suspended during bus_suspend() */
i = HCS_N_PORTS (ehci->hcs_params);
while (i--) {
-
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