Re: 3.15.6 USB issue with pwc cam

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Tuesday 12 August 2014 18:27:03 Hans Verkuil wrote:
> 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/drive
> >>> rs/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.

Right, I've missed the second one, my bad. A similar issue was present with 
the pwc driver, which you have fixed in "[PATCH] pwc: fix WARN_ON" I believe.

I'll have a look at the uvcvideo issue. It can be ignored for now.

-- 
Regards,

Laurent Pinchart