diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
index 01939c57fc74..350f33206076 100644
--- a/drivers/gpu/drm/tegra/fb.c
+++ b/drivers/gpu/drm/tegra/fb.c
@@ -86,6 +86,7 @@ int tegra_fb_get_tiling(struct drm_framebuffer *framebuffer,
 		break;
 
 	default:
+		DRM_DEBUG_KMS("unknown format modifier: %llx\n", modifier);
 		return -EINVAL;
 	}