[PATCH v4 3/5] drm/vmwgfx: Disable damage clipping if FB changed since last page-flip

[Javier Martinez Canillas]

The driver does per-buffer uploads and needs to force a full plane update
if the plane's attached framebuffer has change since the last page-flip.

Suggested-by: Sima Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Reviewed-by: Zack Rusin <zackr@xxxxxxxxxx>
Acked-by: Sima Vetter <daniel.vetter@xxxxxxxx>
---

(no changes since v2)

Changes in v2:
- Set struct drm_plane_state .ignore_damage_clips in vmwgfx plane's
  .atomic_check instead of using a different helpers (Thomas Zimmermann).

 drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index 818b7f109f53..f9364bf222e3 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -837,10 +837,21 @@ int vmw_du_primary_plane_atomic_check(struct drm_plane *plane,
 {
 	struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(state,
 									   plane);
+	struct drm_plane_state *old_state = drm_atomic_get_old_plane_state(state,
+									   plane);
 	struct drm_crtc_state *crtc_state = NULL;
 	struct drm_framebuffer *new_fb = new_state->fb;
+	struct drm_framebuffer *old_fb = old_state->fb;
 	int ret;
 
+	/*
+	 * Ignore damage clips if the framebuffer attached to the plane's state
+	 * has changed since the last plane update (page-flip). In this case, a
+	 * full plane update should happen because uploads are done per-buffer.
+	 */
+	if (old_fb != new_fb)
+		new_state->ignore_damage_clips = true;
+
 	if (new_state->crtc)
 		crtc_state = drm_atomic_get_new_crtc_state(state,
 							   new_state->crtc);
-- 
2.41.0