drm/mediatek: Check plane visibility in atomic_update

Disable the plane if it's not visible. Otherwise mtk_ovl_layer_config()
would proceed with invalid plane and we may see vblank timeout.

Fixes: 119f5173 ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_drm_plane.c

@@ -164,6 +164,16 @@ static int mtk_plane_atomic_check(struct drm_plane *plane,
 						   true, true);
 }
 
+static void mtk_plane_atomic_disable(struct drm_plane *plane,
+				     struct drm_plane_state *old_state)
+{
+	struct mtk_plane_state *state = to_mtk_plane_state(plane->state);
+
+	state->pending.enable = false;
+	wmb(); /* Make sure the above parameter is set before update */
+	state->pending.dirty = true;
+}
+
 static void mtk_plane_atomic_update(struct drm_plane *plane,
 				    struct drm_plane_state *old_state)
 {
@@ -178,6 +188,11 @@ static void mtk_plane_atomic_update(struct drm_plane *plane,
 	if (!crtc || WARN_ON(!fb))
 		return;
 
+	if (!plane->state->visible) {
+		mtk_plane_atomic_disable(plane, old_state);
+		return;
+	}
+
 	gem = fb->obj[0];
 	mtk_gem = to_mtk_gem_obj(gem);
 	addr = mtk_gem->dma_addr;
@@ -200,16 +215,6 @@ static void mtk_plane_atomic_update(struct drm_plane *plane,
 	state->pending.dirty = true;
 }
 
-static void mtk_plane_atomic_disable(struct drm_plane *plane,
-				     struct drm_plane_state *old_state)
-{
-	struct mtk_plane_state *state = to_mtk_plane_state(plane->state);
-
-	state->pending.enable = false;
-	wmb(); /* Make sure the above parameter is set before update */
-	state->pending.dirty = true;
-}
-
 static const struct drm_plane_helper_funcs mtk_plane_helper_funcs = {
 	.prepare_fb = drm_gem_fb_prepare_fb,
 	.atomic_check = mtk_plane_atomic_check,