On 17/09/2024 16:00, Laurent Pinchart wrote:
On Tue, Sep 17, 2024 at 03:43:45PM +0300, Sakari Ailus wrote:Document the expected {enable,disable}_streams callback behaviour for drivers that are stream-unaware i.e. don't specify the V4L2_SUBDEV_CAP_STREAMS sub-device capability flat. In this specific case, the mask argument can be ignored.Wouldn't it be better to use BIT(0) in that case to simplifiy interoperability with stream-aware devices ?
The caller has to set BIT(0), but I think here the documentation is about the callee.
If the driver is not stream aware and implements the callbacks, it will get BIT(0) as the mask parameter (do we enforce this?), but as there's nothing it can do with the parameter it "does not need to be concerned with the mask argument".
Tomi
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> --- include/media/v4l2-subdev.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h index 3cc6b4a5935f..67a6e6ec58b8 100644 --- a/include/media/v4l2-subdev.h +++ b/include/media/v4l2-subdev.h @@ -834,11 +834,19 @@ struct v4l2_subdev_state { * v4l2_subdev_init_finalize() at initialization time). Do not call * directly, use v4l2_subdev_enable_streams() instead. * + * Drivers that support only a single stream without setting the + * V4L2_SUBDEV_CAP_STREAMS sub-device capatility flag do not need to + * be concerned with the mask argument. + * * @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 * v4l2_subdev_init_finalize() at initialization time). Do not call * directly, use v4l2_subdev_disable_streams() instead. + * + * Drivers that support only a single stream without setting the + * V4L2_SUBDEV_CAP_STREAMS sub-device capatility flag do not need to + * be concerned with the mask argument. */ struct v4l2_subdev_pad_ops { int (*enum_mbus_code)(struct v4l2_subdev *sd,
