Re: [PATCH v2] uvcvideo: Work around buggy Logitech C920 firmware

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

Hi William,

On Tuesday 25 March 2014 22:56:33 William Manley wrote:
> On 13/03/14 12:38, William Manley wrote:
> > The uvcvideo webcam driver exposes the v4l2 control "Exposure (Absolute)"
> > which allows the user to control the exposure time of the webcam,
> > essentially controlling the brightness of the received image.  By default
> > the webcam automatically adjusts the exposure time automatically but the
> > if you set the control "Exposure, Auto"="Manual Mode" the user can fix
> > the exposure time.
> > 
> > Unfortunately it seems that the Logitech C920 has a firmware bug where
> > it will forget that it's in manual mode temporarily during initialisation.
> > This means that the camera doesn't respect the exposure time that the user
> > requested if they request it before starting to stream video.  They end up
> > with a video stream which is either too bright or too dark and must reset
> > the controls after video starts streaming.
> > 
> > This patch introduces the quirk UVC_QUIRK_RESTORE_CTRLS_ON_INIT which
> > causes the cached controls to be re-uploaded to the camera immediately
> > after initialising the camera.  This quirk is applied to the C920 to work
> > around this camera bug.
> > 
> > Changes since patch v1:
> >  * Introduce quirk so workaround is only applied to the C920.
> > 
> > Signed-off-by: William Manley <will@williammanley.net>
> 
> Bump?

Sorry, I haven't had the time to handle your patch yet. I'll try to do so on 
Thursday or Friday.

-- 
Regards,

Laurent Pinchart