[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <Pine.LNX.4.44L0.0711211128380.3226-100000@iolanthe.rowland.org>
Date: Wed, 21 Nov 2007 11:31:13 -0500 (EST)
From: Alan Stern <stern@...land.harvard.edu>
To: Markus Rechberger <mrechberger@...il.com>
cc: Oliver Neukum <oliver@...kum.org>,
Laurent Pinchart <laurentp@...-semaphore.com>,
Mark Lord <lkml@....ca>, <linux-kernel@...r.kernel.org>,
<linux-usb-devel@...ts.sourceforge.net>
Subject: Re: [linux-usb-devel] USB deadlock after resume
On Wed, 21 Nov 2007, Markus Rechberger wrote:
> > > 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.
That's very strange. Getting -71 errors is understandable; it
indicates that the device can't handle being suspended. But the
wait_event() line still shouldn't hang. If it does, it indicates that
there's something wrong with the USB host controller, not just the
device.
Can you try testing this on a different sort of computer?
Alan Stern
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists