From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Daniel Ritz <daniel.ritz@gmx.ch>
Subject: Re: [PATCH] uvcvideo: add another YUYV format GUID
Date: Fri, 11 Dec 2009 02:21:30 +0100
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Cc: Mauro Carvalho Chehab <mchehab@infradead.org>, linux-media@vger.kernel.org,
       linux-kernel@vger.kernel.org
References: <1259711324.13720.20.camel@MacRitz2> <200912100246.27827.laurent.pinchart@ideasonboard.com> <1260462865.2138.8.camel@MacRitz2>
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On Thursday 10 December 2009 17:34:25 Daniel Ritz wrote:
> On Thu, 2009-12-10 at 02:46 +0100, Laurent Pinchart wrote:
> > Hi Daniel,
> >
> > On Friday 04 December 2009 03:05:37 Daniel Ritz wrote:
> > > Hi Laurent
> > >
> > > On Thu, 2009-12-03 at 21:15 +0100, Laurent Pinchart wrote:
> > > > Hi Daniel,
> > > >
> > > > On Wednesday 02 December 2009 00:48:44 Daniel Ritz wrote:
> > > > > For some unknown reason, on a MacBookPro5,3 the iSight
> > > >
> > > > Could you please send me the output of lsusb -v both with the correct
> > > > and wrong GUID ?
> > >
> > > sure. i attached three files:
> > >   isight-good.txt, isight-bad.txt, isight-good2.txt
> > >
> > > this is three reboots in a row from like 10 minutes ago. the first
> > > boot into linux was actually rebooting from OSX...first cold boot
> > > today directly into linux had the right GUID.
> >
> > Thanks. diff'ing the descriptors shows something interesting (from good
> > to good2):
> >
> > @@ -264,7 +264,7 @@
> >          dwMaxVideoFrameBufferSize      614400
> >          dwDefaultFrameInterval         333333
> >          bFrameIntervalType                 11
> > -        dwFrameInterval( 0)         3758429717
> > +        dwFrameInterval( 0)            333333
> >          dwFrameInterval( 1)            363636
> >          dwFrameInterval( 2)            400000
> >          dwFrameInterval( 3)            444444
> >
> > 3758429717 is 0xe0051615 in hex, and 333333 is 0x00051615.
> >
> > I wonder what other parts of the descriptors could get corrupted that
> > way.
> 
> hmm..dunno..but even with this it just worked.
> 
> > > > > _sometimes_ report a different video format GUID.
> > > >
> > > > Sometimes only ? Now that's weird. Is that completely random ?
> > >
> > > yes, sometimes only. it seems to be related to reboots, but i don't
> > > know what exactly triggers it. rmmod/modprobe doesn't trigger it.
> > > also, when the wrong GUID is reported, the only way of fixing it is
> > > to reboot. it really is just the GUID. even when the wrong one is
> > > reported, the device works just fine.
> > >
> > > i started with a plain ubuntu 9.10, kernel 2.6.31 which was supposed
> > > to fail, so i upgraded to a 2.6.32-rc8 to fix the iSight and some other
> > > things, just to see it fail again. a reboot later and it worked, some
> > > time and reboot later it failed again...
> >
> > All of those are warm reboots, and you don't boot any alternative OS in-
> > between, right ?
> 
> yes, linux only.
> 
> > Does Linux reload the iSight firmware at every boot ? If it does, could
> > you try to reload the firmware manually when you get a "bad" GUID to see
> > if it helps ? You will probably need to unload the uvcvideo driver before
> > reloading the firmware.
> 
> linux does not load isight firmware at all. the new macbooks don't
> require to load FW the device just "works".
> FW loading is only required for the devices with ID 0x05AC:0x8300,
> what i have is 05ac:8507....

Ok, thanks for the information.

I guess the camera is really broken. As MacOSX probably doesn't even try to 
parse the USB descriptors, the Apple developers never noticed.

Anyway, I'll apply your patch. Can I still keep your SoB line if I rename 
YUY2_2 to YUY2_ISIGHT ?

-- 
Regards,

Laurent Pinchart
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