drm: sti: clear all mixer control

Make sure that mixer control register is correctly reset
before use it.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/sti/sti_mixer.h b/drivers/gpu/drm/sti/sti_mixer.h
index 874372102e52..750e1fd5a8ce 100644
--- a/drivers/gpu/drm/sti/sti_mixer.h
+++ b/drivers/gpu/drm/sti/sti_mixer.h
@@ -39,6 +39,7 @@ struct sti_mixer *sti_mixer_create(struct device *dev, int id,
 
 int sti_mixer_set_layer_status(struct sti_mixer *mixer,
                 struct sti_layer *layer, bool status);
+void sti_mixer_clear_all_layers(struct sti_mixer *mixer);
 int sti_mixer_set_layer_depth(struct sti_mixer *mixer, struct sti_layer *layer);
 int sti_mixer_active_video_area(struct sti_mixer *mixer,
                 struct drm_display_mode *mode);