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From: Pavel Machek <pavel@ucw.cz>
To: Philippe Troin <phil@fifi.org>
Cc: Mohamed Ikbel Boulabiar <boulabiar@gmail.com>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	linux-kernel@vger.kernel.org, linux-media@vger.kernel.org
Subject: Re: webcam problem after suspend/hibernate
Date: Sun, 4 Apr 2010 21:34:06 +0200	[thread overview]
Message-ID: <20100404193405.GA15065@elf.ucw.cz> (raw)
In-Reply-To: <87ljd3ujrp.fsf@old-tantale.fifi.org>

Hi!

> > If unload/reload of uvcvideo helps, it is most likely problem in that.
> > 
> > If unload/reload of ehci_hcd is needed, it is most likely ehci problem.
> 
> My testing shows that:
> 
>  1. If I remove uvcvideo BEFORE suspend and reinsert it after resume,
>     it works.  However, I cannot always rmmod uvcvideo before suspend
>     as it may be in use.
> 
>  2. As a work around, removing ehci_hcd and reinserting ehci_hcd upon
>     resume works as well.
> 
>  3. Since my distribution's kernels come with ehci_hcd built into the
>     kernel, and I cannot do #2 any more, I also found that unbinding
>     and rebinding the device (with the script I sent earlier on) works
>     as well.
> 
> I think uvcvideo is failing to reinitialize the camera on resume, and
> forcing an uvcvideo "reset" with either of these three methods kicks
> uvcvideo into working again.

Ok, that puts the problem firmly into uvcvideo area.

Try changing its _resume routine to whatever is done on device
unplug... it should be rather easy, and is quite close to "correct"
solution.


									Pavel 

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

  reply	other threads:[~2010-04-04 19:33 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-30 21:55 webcam problem after suspend/hibernate Mohamed Ikbel Boulabiar
2010-03-30 23:25 ` Laurent Pinchart
2010-03-31 19:51   ` Mohamed Ikbel Boulabiar
2010-04-01 16:56     ` Pavel Machek
2010-04-01 17:05       ` Philippe Troin
2010-04-04 13:22         ` Pavel Machek
2010-04-04 18:58           ` Philippe Troin
2010-04-04 19:34             ` Pavel Machek [this message]
2010-04-06  9:32               ` Mohamed Ikbel Boulabiar
2010-04-06 13:30                 ` Pavel Machek
2010-04-11 10:53               ` Laurent Pinchart
2010-04-11 15:44                 ` Pavel Machek

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