On Tue, Sep 12, 2023 at 6:22 AM Michel Dänzer <mic...@daenzer.net> wrote:
>
> From: Michel Dänzer <mdaen...@redhat.com>
>
> It was only checking planes which had any state changes in the same
> commit. However, it also needs to check other enabled planes.
>
> Not doing this meant that a commit might spuriously "succeed", resulting
> in the cursor plane displaying with incorrect scaling. See
> https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3177#note_1824263
> for an example.
This looks correct to me, but someone more familiar with this code
should probably double check me.
Reviewed-by: Alex Deucher <alexander.deuc...@amd.com>
>
> Fixes: d1bfbe8a3202 ("amd/display: check cursor plane matches underlying
> plane")
> Signed-off-by: Michel Dänzer <mdaen...@redhat.com>
> ---
> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 14 ++++++++++++--
> 1 file changed, 12 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 88ba8b66de1f..81c9d39567db 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -9836,14 +9836,24 @@ static int dm_check_crtc_cursor(struct
> drm_atomic_state *state,
> * blending properties match the underlying planes'.
> */
>
> - new_cursor_state = drm_atomic_get_new_plane_state(state, cursor);
> - if (!new_cursor_state || !new_cursor_state->fb)
> + new_cursor_state = drm_atomic_get_plane_state(state, cursor);
> + if (IS_ERR(new_cursor_state))
> + return PTR_ERR(new_cursor_state);
> +
> + if (!new_cursor_state->fb)
> return 0;
>
> dm_get_oriented_plane_size(new_cursor_state, &cursor_src_w,
> &cursor_src_h);
> cursor_scale_w = new_cursor_state->crtc_w * 1000 / cursor_src_w;
> cursor_scale_h = new_cursor_state->crtc_h * 1000 / cursor_src_h;
>
> + /* Need to check all enabled planes, even if this commit doesn't
> change
> + * their state
> + */
> + i = drm_atomic_add_affected_planes(state, crtc);
> + if (i)
> + return i;
> +
> for_each_new_plane_in_state_reverse(state, underlying,
> new_underlying_state, i) {
> /* Narrow down to non-cursor planes on the same CRTC as the
> cursor */
> if (new_underlying_state->crtc != crtc || underlying ==
> crtc->cursor)
> --
> 2.40.1
>
