static int ast_crtc_helper_atomic_check(struct drm_crtc *crtc,
                                        struct drm_atomic_state *state)
 {
-       struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
-                                                                         crtc);
+       struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
        struct drm_device *dev = crtc->dev;
        struct ast_crtc_state *ast_state;
        const struct drm_format_info *format;
        bool succ;
+       int ret;
+
+       ret = drm_atomic_helper_check_crtc_state(crtc_state, false);
+       if (ret)
+               return ret;
 
        if (!crtc_state->enable)
-               return 0; /* no mode checks if CRTC is being disabled */
+               goto out;
 
        ast_state = to_ast_crtc_state(crtc_state);
 
        if (!succ)
                return -EINVAL;
 
-       return 0;
+out:
+       return drm_atomic_add_affected_planes(state, crtc);
 }
 
 static void ast_crtc_helper_atomic_begin(struct drm_crtc *crtc, struct drm_atomic_state *state)