[PATCH v4 4/4] drm/mediatek: Fix dereference before null check

[Jason-JH.Lin]

Null-checking state suggests that it may be null, but it has already
been dereferenced on drm_atomic_get_new_plane_state(state, plane).

The parameter state will never be NULL currently, so just remove the
state is NULL flow in this function.

Fixes: 5ddb0bd4ddc3 ("drm/atomic: Pass the full state to planes async atomic check and update")
Signed-off-by: Jason-JH.Lin <jason-jh.lin at mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
Reviewed-by: CK Hu <ck.hu at mediatek.com>
Reviewed-by: Alexandre Mergnat <amergnat at baylibre.com>
---
 drivers/gpu/drm/mediatek/mtk_drm_plane.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
index 1cd41454d545..4828ffa75467 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
@@ -122,11 +122,7 @@ static int mtk_plane_atomic_async_check(struct drm_plane *plane,
 	if (ret)
 		return ret;
 
-	if (state)
-		crtc_state = drm_atomic_get_existing_crtc_state(state,
-								new_plane_state->crtc);
-	else /* Special case for asynchronous cursor updates. */
-		crtc_state = new_plane_state->crtc->state;
+	crtc_state = drm_atomic_get_existing_crtc_state(state, new_plane_state->crtc);
 
 	return drm_atomic_helper_check_plane_state(plane->state, crtc_state,
 						   DRM_PLANE_NO_SCALING,
-- 
2.18.0