Re: 3.15.6 USB issue with pwc cam

[Hans Verkuil <hverkuil@xs4all.nl>]

On 08/12/2014 06:21 PM, Laurent Pinchart wrote:
> Hi Hans,
> 
> On Tuesday 12 August 2014 17:38:55 Hans Verkuil wrote:
>> On 08/12/2014 05:07 PM, Hans de Goede wrote:
>>> On 08/07/2014 04:49 PM, Udo van den Heuvel wrote:
>>>> On 2014-08-04 11:17, Laurent Pinchart wrote:
>>>>> (CC'ing Hans de Goede, the pwc maintainer, and the linux-media mailing
>>>>> list)
>>>
>>> Thanks for the bug report. I've been looking into this, and there
>>> seem to be 2 problems:
>>>
>>> 1: xhci_hcd 0000:02:00.0: ERROR: unexpected command completion code 0x11.
>>>
>>> This seems to be what is causing things to not work with a usb-3 port
>>> for you. Might be fixed by this commit:
>>> https://git.kernel.org/cgit/linux/kernel/git/gregkh/usb.git/commit/drivers
>>> /usb/host?h=usb-next&id=3213b151387df0b95f4eada104f68eb1c1409cb3
>>>
>>> Can you please do "lspci -nn", and then copy and paste the output here,
>>> so that we can see what sort of xhci controller you've (and try to
>>> reproduce the problem).
>>>
>>> 2: The triggering of a WARN_ON in __vb2_queue_cancel() when called on
>>> streamoff. I've been looking at the code and I cannot figure out why this
>>> is triggering I'm afraid.
>>
>> You can ignore this one.
>>
>> The uvc driver is doing messy things with vb2 which causes this warning.
>> That said, it will not break things for you. It is just a warning that the
>> driver needs to be improved.
> 
> I can certainly take the blame when my code needs to be improved, but in this 
> case the webcam is supported by the pwc driver, not the uvc driver :-)
> 

It was a bit confusing, but he has two problems: one pwc, one (the warning) for
uvc.

Regards,

	Hans