drm: clean up renderer texture cache

src/backend/drm/compositor/mod.rs

@@ -1952,6 +1952,13 @@ where
 
             match render_res {
                 Ok(render_output_result) => {
+                    if render_output_result.damage.is_none() {
+                        // if we receive no damage we can assume no rendering took place
+                        // and we should trigger a cleanup of the renderer texture cache
+                        // to prevent holding textures longer then necessary
+                        renderer.cleanup_texture_cache();
+                    }
+
                     for (id, state) in render_output_result.states.states.into_iter() {
                         // Skip the state for our fake elements
                         if self.overlay_plane_element_ids.contains_plane_id(&id) {
@@ -2037,6 +2044,11 @@ where
                     return Err(RenderFrameError::from(err));
                 }
             }
+        } else {
+            // if we are constantly doing direct scan-out on the primary plane
+            // we have to cleanup the renderer texture cache as this would
+            // only happen implicit during rendering otherwise
+            renderer.cleanup_texture_cache();
         }
 
         self.next_frame = Some(next_frame_state);