Re: [PATCH] uvcvideo: add another YUYV format GUID

[Daniel Ritz <daniel.ritz@gmx.ch>]

On 11.12.2009 02:21, Laurent Pinchart wrote:
> 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 ?

sure.

thanks, rgds
-daniel