Re: [PATCH v4 23/29] media: Improve enable_streams and disable_streams documentation

Laurent Pinchart
2026-04-16T15:49:19Z

On Wed, Apr 08, 2026 at 06:39:32PM +0300, Sakari Ailus wrote:
> Document that enable_streams may start additional streams and
> disable_streams may not disable requested streams if other related streams
> are still enabled.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> Reviewed-by: Mirela Rabulea <mirela.rabulea@nxp.com>
> ---
> include/media/v4l2-subdev.h | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> index d256b7ec8f84..4588992b4417 100644
> --- a/include/media/v4l2-subdev.h
> +++ b/include/media/v4l2-subdev.h
> @@ -814,6 +814,10 @@ struct v4l2_subdev_state {
> * V4L2_SUBDEV_CAP_STREAMS sub-device capability flag can ignore the mask
> * argument.
> *
> + * Starting the requested streams may require starting additional
> + * streams. Streams that are started together due to hardware are called a
> + * stream group.
> + *
> * @disable_streams: Disable the streams defined in streams_mask on the given
> * source pad. Subdevs that implement this operation must use the active
> * state management provided by the subdev core (enabled through a call to
> @@ -823,6 +827,9 @@ struct v4l2_subdev_state {
> * Drivers that support only a single stream without setting the
> * V4L2_SUBDEV_CAP_STREAMS sub-device capability flag can ignore the mask
> * argument.
> + *
> + * A stream group is disabled when one or more streams in the stream
> + * group are disabled.

This contradicts the commit message. Did you mean that a stream group
will be disabled when all the streams it contains are disabled ?

> */
> struct v4l2_subdev_pad_ops {
> int (*enum_mbus_code)(struct v4l2_subdev *sd,

--
Regards,

Laurent Pinchart