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

[Sakari Ailus]

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@xxxxxxxxxx>
> ---
>  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@xxxxxx	XMPP: sailus@xxxxxxxxxxxxxx