Re: [PATCH v4 20/29] media: uapi: Bump the STREAMS bit a little

Jacopo Mondi
2026-04-10T09:31:11Z

Hi Sakari

On Wed, Apr 08, 2026 at 06:39:29PM +0300, Sakari Ailus wrote:
> Bump the V4L2_SUBDEV_CAP_STREAMS by one bit up, order to avoid confusing
> libcamera with streams that has moved forward from the original libcamera
> implementation. The bit can presumably be taken into use but only after
> the other free bits.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Thanks!
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

> ---
> include/uapi/linux/v4l2-subdev.h | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h
> index 2347e266cf75..6160c3e21436 100644
> --- a/include/uapi/linux/v4l2-subdev.h
> +++ b/include/uapi/linux/v4l2-subdev.h
> @@ -196,8 +196,11 @@ struct v4l2_subdev_capability {
> /* The v4l2 sub-device video device node is registered in read-only mode. */
> #define V4L2_SUBDEV_CAP_RO_SUBDEV 0x00000001
>
> +/* Reserved, old STREAMS bit libcamera used before API stabilisation. */
> +/* #define V4L2_SUBDEV_CAP_STREAMS_PRELIMINARY 0x00000002 */

This should make sure libcamera versions which support the new flag
won't match agains older kernel which use the old value!

> +
> /* The v4l2 sub-device supports routing and multiplexed streams. */
> -#define V4L2_SUBDEV_CAP_STREAMS 0x00000002
> +#define V4L2_SUBDEV_CAP_STREAMS 0x00000004
>
> /*
> * Is the route active? An active route will start when streaming is enabled
> --
> 2.47.3
>
>