Re: [PATCH 07/23] drm/object: Add default zpos value at reset

[Harry Wentland <harry.wentland@amd.com>]

On 2022-02-07 11:34, Maxime Ripard wrote:
> From: Dave Stevenson <dave.stevenson@raspberrypi.com>
> 
> The drm_plane_create_zpos_property() function asks for an initial value,
> and will set the associated plane state variable with that value if a
> state is present.
> 
> However, that function is usually called at a time where there's no
> state yet. Since the drm_plane_state reset helper doesn't take care of
> reading that value when it's called, it means that in most cases the
> initial value will be 0, or the drivers will have to work around it.
> 
> Let's add some code in __drm_atomic_helper_plane_state_reset() to get
> the initial zpos value if the property has been attached in order to fix
> this.
> 
> Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

> ---
>  drivers/gpu/drm/drm_atomic_state_helper.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
> index ddcf5c2c8e6a..1412cee404ca 100644
> --- a/drivers/gpu/drm/drm_atomic_state_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_state_helper.c
> @@ -243,11 +243,22 @@ EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);
>  void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *plane_state,
>  					   struct drm_plane *plane)
>  {
> +	u64 val;
> +
>  	plane_state->plane = plane;
>  	plane_state->rotation = DRM_MODE_ROTATE_0;
>  
>  	plane_state->alpha = DRM_BLEND_ALPHA_OPAQUE;
>  	plane_state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI;
> +
> +	if (plane->zpos_property) {
> +		if (!drm_object_property_get_default_value(&plane->base,
> +							   plane->zpos_property,
> +							   &val)) {
> +			plane_state->zpos = val;
> +			plane_state->normalized_zpos = val;
> +		}
> +	}
>  }
>  EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset);
>