Re: [PATCH] usb ehci_iaa_watchdog fix

From: David Brownell
Date: Wed Apr 02 2008 - 16:43:37 EST


On Wednesday 02 April 2008, Alan Stern wrote:
> > -     if (ehci->reclaim
> > -                     && !timer_pending(&ehci->iaa_watchdog)
> > -                     && HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
> > +     if (ehci->reclaim && !timer_pending(&ehci->iaa_watchdog)) {
> >               u32 cmd, status;
> >  
> >               /* If we get here, IAA is *REALLY* late.  It's barely
>
> Okay, I'm puzzled.  How could this make any difference?

It's more like: what else in that patch could have had
any such effect? That HC_IS_RUNNING test was the only
candidate.

Those hcd->state tests have been getting more and more
dodgey as time goes by. At this point I hardly trust
any of them. There *IS* no clear state machine which
governs the usbcore/HCD interaction.

- Dave


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