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SubjectRe: WARNING: at drivers/usb/host/ehci-hcd.c:287
On Tue, 4 Mar 2008, David Brownell wrote:

> On Tuesday 04 March 2008, Alan Stern wrote:
> > Dave, it seems to me that this must be an example of a race between the
> > iaa watchdog timer expiring and end_unlink_async() running.  It's not
> > good enough for end_unlink_async() to call iaa_watchdog_done(), because
> > on an SMP system the timer may already have fired and the watchdog
> > routine may be spinning on ehci->lock.
>
> Right.
>
>
> > How about replacing the
> >
> >         WARN_ON(!ehci->reclaim);
>
> Or bettter yet, just removing it entirely. ISTR doing that in some
> patches I've not yet sent for merging, and expect that's what my
> preferred fix will be ...

But removing the WARN_ON won't fix the problem. The routine still
needs to exit immediately if ehci->reclaim isn't set, the root hub
isn't running, or the timer has been restarted.

Alan Stern

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