On Mo, 2023-11-27 at 13:13 +0200, Laurent Pinchart wrote: > Due to a historical mishap, the v4l2_subdev_frame_interval structure > is the only part of the V4L2 subdev userspace API that doesn't contain a > 'which' field. This prevents trying frame intervals using the subdev > 'TRY' state mechanism. > > Adding a 'which' field is simple as the structure has 8 reserved fields. > This would however break userspace as the field is currently set to 0, > corresponding to V4L2_SUBDEV_FORMAT_TRY, while the corresponding ioctls > currently operate on the 'ACTIVE' state. We thus need to add a new > subdev client cap, V4L2_SUBDEV_CLIENT_CAP_WHICH_INTERVAL, to indicate > that userspace is aware of this new field. > > All drivers that implement the subdev .get_frame_interval() and > .set_frame_interval() operations are updated to return -EINVAL when > operating on the TRY state, preserving the current behaviour. > > While at it, fix a bad copy&paste in the documentation of the struct > v4l2_subdev_frame_interval_enum 'which' field. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> # for imx-media regards Philipp
