On Wed, 12 Dec 2007, David Brownell wrote:
> On Tuesday 11 December 2007, Alan Stern wrote:
> > Dave:
> >
> > I just tried doing some hibernation testing, and my external high-speed
> > hub is behaving very strangely. The test is simple. First plug in the
> > hub, then plug a flash drive into the hub to keep it from
> > autosuspending. Then:
> >
> > echo test >/sys/power/disk
> > echo disk >/sys/power/state
> >
> > The first line causes the hibernation to stop after the PM_EVENT_FREEZE
> > message has been sent; after that everything is woken back up. There
> > are no bus-power-level changes since the EHCI controller remains in D0
> > throughout.
> >
> > This sequence causes the hub to disconnect and reconnect itself! When
> > khubd starts running again, it sees the port-connect-change event.
> This doesn't ring any bells with me. It seems buglike. :)
Well, I can't tell exactly what the cause is. But this patch fixes it.
Look okay to you?
Alan Stern
This patch (as1029) adds a short delay to the bus-suspend routine in
ehci-hcd. Without it some devices disconnect when they should
suspend.
The patch also moves a del_timer_sync() call outside the scope of a
spinlock, where it could cause a deadlock, and adds a new
del_timer_sync() call for the new IAA watchdog timer (it was omitted
by mistake).
Signed-off-by: Alan Stern <[EMAIL PROTECTED]>
---
Index: usb-2.6/drivers/usb/host/ehci-hub.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-hub.c
+++ usb-2.6/drivers/usb/host/ehci-hub.c
@@ -170,8 +170,11 @@ static int ehci_bus_suspend (struct usb_
}
}
+ /* Apparently some devices need a 1-uframe delay here */
+ if (ehci->bus_suspended)
+ udelay(125);
+
/* turn off now-idle HC */
- del_timer_sync (&ehci->watchdog);
ehci_halt (ehci);
hcd->state = HC_STATE_SUSPENDED;
@@ -184,6 +187,9 @@ static int ehci_bus_suspend (struct usb_
ehci->next_statechange = jiffies + msecs_to_jiffies(10);
spin_unlock_irq (&ehci->lock);
+
+ del_timer_sync(&ehci->watchdog);
+ del_timer_sync(&ehci->iaa_watchdog);
return 0;
}
-
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