omap3isp: isp_video_mbus_to_pix causes WARN_ON

omap3isp: isp_video_mbus_to_pix causes WARN_ON

[Chris Whittenburg]

I'm using a 3.0.17 kernel on a dm3730 with a custom 8-bit grayscale sensor.

When using a simple gstreamer pipeline to test:

gst-launch -v v4l2src device=/dev/video2 !
'video/x-raw-gray,bpp=(int)8,framerate=(fraction)10/1,width=640,height=480'
! fakesink

I get lots of calls to isp_video_try_format for unrelated formats like
YU12, YV12, BGR3, and RGB3.  I assume this is gstreamer's fault, since
I implemented isp_video_enum_format which only returns
V4L2_PIX_FMT_GREY.

Anyway, isp_video_try_format makes calls to isp_video_pix_to_mbus for
each of these formats, and since they aren't in the list of
isp_format_info formats, WARN_ON gets called.

Is this expected?  What would be the best way to resolve it?

Thanks.

Re: omap3isp: isp_video_mbus_to_pix causes WARN_ON

[Laurent Pinchart]

Hi Chris,

On Thursday 26 April 2012 10:54:58 Chris Whittenburg wrote:
> I'm using a 3.0.17 kernel on a dm3730 with a custom 8-bit grayscale sensor.
> 
> When using a simple gstreamer pipeline to test:
> 
> gst-launch -v v4l2src device=/dev/video2 !
> 'video/x-raw-gray,bpp=(int)8,framerate=(fraction)10/1,width=640,height=480'
> ! fakesink
> 
> I get lots of calls to isp_video_try_format for unrelated formats like
> YU12, YV12, BGR3, and RGB3.  I assume this is gstreamer's fault, since
> I implemented isp_video_enum_format which only returns
> V4L2_PIX_FMT_GREY.
> 
> Anyway, isp_video_try_format makes calls to isp_video_pix_to_mbus for
> each of these formats, and since they aren't in the list of
> isp_format_info formats, WARN_ON gets called.
> 
> Is this expected?  What would be the best way to resolve it?

This has been fixed in

commit c3cd257402fdcd650816ec25b83480a24912430a
Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date:   Mon Nov 28 08:25:30 2011 -0300

    [media] omap3isp: video: Don't WARN() on unknown pixel formats
    
    When mapping from a V4L2 pixel format to a media bus format in the
    VIDIOC_TRY_FMT and VIDIOC_S_FMT handlers, the requested format may be
    unsupported by the driver. Return a hardcoded format instead of
    WARN()ing in that case.
    
    Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
    Acked-by: Sakari Ailus <sakari.ailus@iki.fi>
    Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

-- 
Regards,

Laurent Pinchart