[PATCH v4 13/36] [media] v4l2: add a frame timeout event

Sakari Ailus
2017-03-02T15:53:45Z

Hi Steve,

On Wed, Feb 15, 2017 at 06:19:15PM -0800, Steve Longerbeam wrote:
> Add a new FRAME_TIMEOUT event to signal that a video capture or
> output device has timed out waiting for reception or transmit
> completion of a video frame.
>
> Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
> ---
> Documentation/media/uapi/v4l/vidioc-dqevent.rst | 5 +++++
> Documentation/media/videodev2.h.rst.exceptions | 1 +
> include/uapi/linux/videodev2.h | 1 +
> 3 files changed, 7 insertions(+)
>
> diff --git a/Documentation/media/uapi/v4l/vidioc-dqevent.rst b/Documentation/media/uapi/v4l/vidioc-dqevent.rst
> index 8d663a7..dd77d9b 100644
> --- a/Documentation/media/uapi/v4l/vidioc-dqevent.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-dqevent.rst
> @@ -197,6 +197,11 @@ call.
> the regions changes. This event has a struct
> :c:type:`v4l2_event_motion_det`
> associated with it.
> + * - ``V4L2_EVENT_FRAME_TIMEOUT``
> + - 7
> + - This event is triggered when the video capture or output device
> + has timed out waiting for the reception or transmit completion of
> + a frame of video.

As you're adding a new interface, I suppose you have an implementation
around. How do you determine what that timeout should be?

> * - ``V4L2_EVENT_PRIVATE_START``
> - 0x08000000
> - Base event number for driver-private events.
> diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions
> index e11a0d0..5b0f767 100644
> --- a/Documentation/media/videodev2.h.rst.exceptions
> +++ b/Documentation/media/videodev2.h.rst.exceptions
> @@ -459,6 +459,7 @@ replace define V4L2_EVENT_CTRL event-type
> replace define V4L2_EVENT_FRAME_SYNC event-type
> replace define V4L2_EVENT_SOURCE_CHANGE event-type
> replace define V4L2_EVENT_MOTION_DET event-type
> +replace define V4L2_EVENT_FRAME_TIMEOUT event-type
> replace define V4L2_EVENT_PRIVATE_START event-type
>
> replace define V4L2_EVENT_CTRL_CH_VALUE ctrl-changes-flags
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 46e8a2e3..e174c45 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -2132,6 +2132,7 @@ struct v4l2_streamparm {
> #define V4L2_EVENT_FRAME_SYNC 4
> #define V4L2_EVENT_SOURCE_CHANGE 5
> #define V4L2_EVENT_MOTION_DET 6
> +#define V4L2_EVENT_FRAME_TIMEOUT 7
> #define V4L2_EVENT_PRIVATE_START 0x08000000
>
> /* Payload for V4L2_EVENT_VSYNC */

--
Regards,

Sakari Ailus
e-mail: sakari.ailus at iki.fi XMPP: sailus at retiisi.org.uk