Re: [PATCH v5 2/3] drm: Allow drivers to choose plane types to async flip

[Ville Syrjälä]

On Wed, Jun 12, 2024 at 04:37:12PM -0300, André Almeida wrote:
> Different planes may have different capabilities of doing async flips,
> so create a field to let drivers allow async flip per plane type.
> 
> Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/drm_atomic_uapi.c | 4 ++--
>  drivers/gpu/drm/drm_plane.c       | 3 +++
>  include/drm/drm_plane.h           | 5 +++++
>  3 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
> index 2e1d9391febe..dd4b1578f141 100644
> --- a/drivers/gpu/drm/drm_atomic_uapi.c
> +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> @@ -1079,9 +1079,9 @@ int drm_atomic_set_property(struct drm_atomic_state *state,
>  			break;
>  		}
>  
> -		if (async_flip && plane_state->plane->type != DRM_PLANE_TYPE_PRIMARY) {
> +		if (async_flip && !plane_state->plane->async_flip) {

You alreayd have 'plane', no need to dog it out again.

>  			drm_dbg_atomic(prop->dev,
> -				       "[OBJECT:%d] Only primary planes can be changed during async flip\n",
> +				       "[OBJECT:%d] This type of plane cannot be changed during async flip\n",
>  				       obj->id);

"[PLANE:%d:%s] does not support async flips"
or something like it would make more sense to me.

>  			ret = -EINVAL;
>  			break;
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index 57662a1fd345..bbcec3940636 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -385,6 +385,9 @@ static int __drm_universal_plane_init(struct drm_device *dev,
>  
>  	drm_modeset_lock_init(&plane->mutex);
>  
> +	if (type == DRM_PLANE_TYPE_PRIMARY)
> +		plane->async_flip = true;

Setting that would be the job of the driver.

You could probably just nuke mode_config.async_page_flip
and replace it fully with plane.async_flip checks.

> +
>  	plane->base.properties = &plane->properties;
>  	plane->dev = dev;
>  	plane->funcs = funcs;
> diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
> index 9507542121fa..0bebc72af5c3 100644
> --- a/include/drm/drm_plane.h
> +++ b/include/drm/drm_plane.h
> @@ -786,6 +786,11 @@ struct drm_plane {
>  	 * @kmsg_panic: Used to register a panic notifier for this plane
>  	 */
>  	struct kmsg_dumper kmsg_panic;
> +
> +	/**
> +	 * @async_flip: indicates if a plane can do async flips
> +	 */
> +	bool async_flip;
>  };
>  
>  #define obj_to_plane(x) container_of(x, struct drm_plane, base)
> -- 
> 2.45.2

-- 
Ville Syrjälä
Intel