Re: USB deadlock after resume

["Markus Rechberger" <mrechberger@gmail.com>]

On 11/21/07, Oliver Neukum <oliver@neukum.org> wrote:
> Am Mittwoch 21 November 2007 schrieb Markus Rechberger:
> > On 11/21/07, Markus Rechberger <mrechberger@gmail.com> wrote:
> > > On 11/21/07, Mark Lord <lkml@rtr.ca> wrote:
> > > > Markus Rechberger wrote:
> > > > > Hi,
> > > > >
> > > > > I'm looking at the linux uvc driver, and noticed after resuming my
> > > > ..
> > > >
> > > > Pardon me.. what is the "uvc" driver?  Which module/source file is
> that?
> > > >
> > >
> > > http://linux-uvc.berlios.de/ it's not yet included in the kernel
> > > sources although many distributions already ship it.
> > > A "dry" run putting the device into sleep mode works fine (I added a
> > > proc interface for calling those suspend/resume function).
> > >
> >
> > it's not just usb_set_interface that hangs actually.
> > It seems to hang at
> >
> > wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0);
> >
> > in drivers/usb/core/urb.c after resuming. I disabled access to the usb
> > subsystem in the uvc driver, although connecting any other usb storage
> > fails too, just at the same point.
>
> Which URB is usb_kill_urb() called for?
>

it's the usb_control_message which calls usb_kill_urb if I haven't got
it wrong. (if you're looking for some other information please let me
know)
Although, I got a bit further with it. The error seems to happen
earlier already.
If I load the driver, and do not access the device after suspending
all usb_control commands fail with -71 eproto.

Reloading the driver doesn't help at tht point, only reconnecting the
device does.

The data is transfered using bulk transfer.

Markus
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