* Mode config
  */
 
+static const struct drm_mode_config_helper_funcs
+ast_mode_config_helper_funcs = {
+       .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
+};
+
 static const struct drm_mode_config_funcs ast_mode_config_funcs = {
        .fb_create = drm_gem_fb_create,
        .mode_valid = drm_vram_helper_mode_valid,
                dev->mode_config.max_height = 1200;
        }
 
+       dev->mode_config.helper_private = &ast_mode_config_helper_funcs;
+
        memset(&ast->primary_plane, 0, sizeof(ast->primary_plane));
        ret = drm_universal_plane_init(dev, &ast->primary_plane, 0x01,
                                       &ast_primary_plane_funcs,