if (dev_priv->active_display_unit == vmw_du_screen_target &&
                    (drm_rect_width(&rects[i]) > dev_priv->stdu_max_width ||
                     drm_rect_height(&rects[i]) > dev_priv->stdu_max_height)) {
-                       DRM_ERROR("Screen size not supported.\n");
+                       VMW_DEBUG_KMS("Screen size not supported.\n");
                        return -EINVAL;
                }
 
         * limit on primary bounding box
         */
        if (pixel_mem > dev_priv->prim_bb_mem) {
-               DRM_ERROR("Combined output size too large.\n");
+               VMW_DEBUG_KMS("Combined output size too large.\n");
                return -EINVAL;
        }
 
                bb_mem = (u64) bounding_box.x2 * bounding_box.y2 * 4;
 
                if (bb_mem > dev_priv->prim_bb_mem) {
-                       DRM_ERROR("Topology is beyond supported limits.\n");
+                       VMW_DEBUG_KMS("Topology is beyond supported limits.\n");
                        return -EINVAL;
                }
        }
                struct vmw_connector_state *vmw_conn_state;
 
                if (!du->pref_active && new_crtc_state->enable) {
+                       VMW_DEBUG_KMS("Enabling a disabled display unit\n");
                        ret = -EINVAL;
                        goto clean;
                }
                return ret;
 
        ret = vmw_kms_check_implicit(dev, state);
-       if (ret)
+       if (ret) {
+               VMW_DEBUG_KMS("Invalid implicit state\n");
                return ret;
+       }
 
        for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
                if (drm_atomic_crtc_needs_modeset(crtc_state))
                if (drm_rects[i].x1 < 0 ||  drm_rects[i].y1 < 0 ||
                    drm_rects[i].x2 > mode_config->max_width ||
                    drm_rects[i].y2 > mode_config->max_height) {
-                       DRM_ERROR("Invalid GUI layout.\n");
+                       VMW_DEBUG_KMS("Invalid layout %d %d %d %d\n",
+                                     drm_rects[i].x1, drm_rects[i].y1,
+                                     drm_rects[i].x2, drm_rects[i].y2);
                        ret = -EINVAL;
                        goto out_free;
                }