diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index e2373d1cfebcf..e4c46a75af905 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -1265,8 +1265,10 @@ static int prepare_signaling(struct drm_device *dev,
 	 * Having this flag means user mode pends on event which will never
 	 * reach due to lack of at least one CRTC for signaling
 	 */
-	if (c == 0 && (arg->flags & DRM_MODE_PAGE_FLIP_EVENT))
+	if (c == 0 && (arg->flags & DRM_MODE_PAGE_FLIP_EVENT)) {
+		drm_dbg_atomic(dev, "need at least one CRTC for DRM_MODE_PAGE_FLIP_EVENT");
 		return -EINVAL;
+	}
 
 	return 0;
 }