Re: [PATCH v2 2/3] usb: gadget/uvc: also handle v4l2 ioctl ENUM_FMT

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

Hi Hans and Michael,

On Wednesday 20 August 2014 02:06:54 Hans Verkuil wrote:
> On 08/19/2014 05:01 PM, Laurent Pinchart wrote:
> > Hi Michael,
> > 
> > Thank you for the patch.
> > 
> > (CC'ing Hans Verkuil and the linux-media mailing list)
> > 
> > On Friday 08 August 2014 17:38:58 Michael Grzeschik wrote:
> >> This patch adds ENUM_FMT as possible ioctl to the uvc v4l2 device.
> >> That makes userspace applications with a generic IOCTL calling
> >> convention make also use of it.
> >> 
> >> Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
> >> ---
> >> 
> >> v1 -> v2:
> >>  - changed first switch case to simple if
> >>  - added separate function
> >>  - added description field
> >>  - bail out on array boundaries
> >>  
> >>  drivers/usb/gadget/uvc_v4l2.c | 30 ++++++++++++++++++++++++++++--
> >>  1 file changed, 28 insertions(+), 2 deletions(-)
> >> 
> >> diff --git a/drivers/usb/gadget/uvc_v4l2.c
> >> b/drivers/usb/gadget/uvc_v4l2.c
> >> index ad48e81..58633bf 100644
> >> --- a/drivers/usb/gadget/uvc_v4l2.c
> >> +++ b/drivers/usb/gadget/uvc_v4l2.c
> >> @@ -55,14 +55,30 @@ struct uvc_format
> >>  {
> >>  	u8 bpp;
> >>  	u32 fcc;
> >> +	char *description;
> >>  };
> >>  
> >>  static struct uvc_format uvc_formats[] = {
> >> -	{ 16, V4L2_PIX_FMT_YUYV  },
> >> -	{ 0,  V4L2_PIX_FMT_MJPEG },
> >> +	{ 16, V4L2_PIX_FMT_YUYV, "YUV 4:2:2" },
> >> +	{ 0,  V4L2_PIX_FMT_MJPEG, "MJPEG" },
> > 
> > Format descriptions are currently duplicated in every driver, causing
> > higher memory usage and different descriptions for the same format
> > depending on the driver. Hans, should we try to fix this ?
> 
> Yes, we should. It's been on my todo list for ages, but at a very low
> priority. I'm not planning to work on this in the near future, but if
> someone else wants to work on this, then just go ahead.

Michael, would you like to give this a try, or should I do it ?

-- 
Regards,

Laurent Pinchart