backend/drm: check drm_surface_render_black_frame return value
This avoids hitting an assertion in drm_fb_lock_surface when
we failed to render a black frame.
@@ -681,7 +681,9 @@ static bool drm_connector_pageflip_renderer(struct wlr_drm_connector *conn) {
// drm_crtc_page_flip expects a FB to be available
struct wlr_drm_plane *plane = crtc->primary;
if (!plane_get_next_fb(plane)->bo) {
- drm_surface_render_black_frame(&plane->surf);
+ if (!drm_surface_render_black_frame(&plane->surf)) {
+ return false;
+ }
if (!drm_fb_lock_surface(&plane->pending_fb, &plane->surf)) {
return false;
}
