[PATCH 6/7] drm/atomic: log when page-flip is requested without CRTCs

[Simon Ser <contact@xxxxxxxxxxx>]

Signed-off-by: Simon Ser <contact@xxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
---
 drivers/gpu/drm/drm_atomic_uapi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index 3df3f7ba0af3..b996351beb57 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -1261,8 +1261,10 @@ 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;
 }
-- 
2.38.0