[PATCH] drm/amd/display: fix cursor-plane-only atomic commits not triggering pageflips

[Harry Wentland]

On 2023-12-07 13:25, Xaver Hugl wrote:
> With VRR, every atomic commit affecting a given display must trigger
> a new scanout cycle, so that userspace is able to control the refresh
> rate of the display. Before this commit, this was not the case for
> atomic commits that only contain cursor plane properties.
> 
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3034
> Cc: stable at vger.kernel.org
> 
> Signed-off-by: Xaver Hugl <xaver.hugl at gmail.com>

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

Harry

> ---
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 ++++++++--
>   1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index b452796fc6d3..b379c859fbef 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -8149,9 +8149,15 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
>   		/* Cursor plane is handled after stream updates */
>   		if (plane->type == DRM_PLANE_TYPE_CURSOR) {
>   			if ((fb && crtc == pcrtc) ||
> -			    (old_plane_state->fb && old_plane_state->crtc == pcrtc))
> +			    (old_plane_state->fb && old_plane_state->crtc == pcrtc)) {
>   				cursor_update = true;
> -
> +				/*
> +				 * With atomic modesetting, cursor changes must
> +				 * also trigger a new refresh period with vrr
> +				 */
> +				if (!state->legacy_cursor_update)
> +					pflip_present = true;
> +			}
>   			continue;
>   		}
>