drm/virtio: Disable damage clipping if FB changed since last page-flip

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.

Fixes: 01f05940a9a7 ("drm/virtio: Enable fb damage clips property for the primary plane")
Cc: <stable@vger.kernel.org> # v6.4+
Reported-by: nerdopolis <bluescreen_avenger@verizon.net>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218115
Suggested-by: Sima Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Zack Rusin <zackr@vmware.com>
Acked-by: Sima Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20231123221315.3579454-3-javierm@redhat.com

diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 20de599658c1ff7b38f0d13a4a5c61f4d1181315..a72a2dbda031c220e62d018f3b77aab4bb0401d3 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -79,6 +79,8 @@ static int virtio_gpu_plane_atomic_check(struct drm_plane *plane,
 {
        struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
                                                                                 plane);
+       struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state,
+                                                                                plane);
        bool is_cursor = plane->type == DRM_PLANE_TYPE_CURSOR;
        struct drm_crtc_state *crtc_state;
        int ret;
@@ -86,6 +88,14 @@ static int virtio_gpu_plane_atomic_check(struct drm_plane *plane,
        if (!new_plane_state->fb || WARN_ON(!new_plane_state->crtc))
                return 0;
 
+       /*
+        * 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_plane_state->fb != new_plane_state->fb)
+               new_plane_state->ignore_damage_clips = true;
+
        crtc_state = drm_atomic_get_crtc_state(state,
                                               new_plane_state->crtc);
        if (IS_ERR(crtc_state))