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@xxxxxxxxxxxxxxxxx> Bump? -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
