drm/tidss: Annotate dma-fence critical section in commit path

Ends right after hw_done(), totally standard case.
Acked-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jyri Sarha <jsarha@ti.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210121152959.1725404-12-daniel.vetter@ffwll.ch

drivers/gpu/drm/tidss/tidss_kms.c

@@ -4,6 +4,8 @@
  * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
  */
 
+#include <linux/dma-fence.h>
+
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
@@ -26,6 +28,7 @@ static void tidss_atomic_commit_tail(struct drm_atomic_state *old_state)
 {
 	struct drm_device *ddev = old_state->dev;
 	struct tidss_device *tidss = to_tidss(ddev);
+	bool fence_cookie = dma_fence_begin_signalling();
 
 	dev_dbg(ddev->dev, "%s\n", __func__);
 
@@ -36,6 +39,7 @@ static void tidss_atomic_commit_tail(struct drm_atomic_state *old_state)
 	drm_atomic_helper_commit_modeset_enables(ddev, old_state);
 
 	drm_atomic_helper_commit_hw_done(old_state);
+	dma_fence_end_signalling(fence_cookie);
 	drm_atomic_helper_wait_for_flip_done(ddev, old_state);
 
 	drm_atomic_helper_cleanup_planes(ddev, old_state);