diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
index fbb8ae8be6ba..9e551ca3ef79 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
@@ -443,9 +443,9 @@ of_parse_display_resource(struct drm_device *drm_dev, struct device_node *route)
 	return set;
 }
 
-int setup_initial_state(struct drm_device *drm_dev,
-			struct drm_atomic_state *state,
-			struct rockchip_drm_mode_set *set)
+static int setup_initial_state(struct drm_device *drm_dev,
+			       struct drm_atomic_state *state,
+			       struct rockchip_drm_mode_set *set)
 {
 	struct rockchip_drm_private *priv = drm_dev->dev_private;
 	struct drm_connector *connector = set->connector;
@@ -1630,7 +1630,7 @@ static void rockchip_drm_postclose(struct drm_device *dev, struct drm_file *file
 	file->driver_priv = NULL;
 }
 
-void rockchip_drm_lastclose(struct drm_device *dev)
+static void rockchip_drm_lastclose(struct drm_device *dev)
 {
 	struct rockchip_drm_private *priv = dev->dev_private;
 
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
index a85d12eb98cc..b37eea0232a1 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
@@ -317,9 +317,9 @@ void rockchip_drm_atomic_work(struct work_struct *work)
 	private->commit = NULL;
 }
 
-int rockchip_drm_atomic_commit(struct drm_device *dev,
-			       struct drm_atomic_state *state,
-			       bool async)
+static int rockchip_drm_atomic_commit(struct drm_device *dev,
+				      struct drm_atomic_state *state,
+				      bool async)
 {
 	struct rockchip_drm_private *private = dev->dev_private;
 	struct rockchip_atomic_commit *commit;
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index df966d4b233a..71ed1c6e14fd 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1789,7 +1789,7 @@ static const struct drm_plane_helper_funcs plane_helper_funcs = {
 	.atomic_disable = vop_plane_atomic_disable,
 };
 
-void vop_atomic_plane_reset(struct drm_plane *plane)
+static void vop_atomic_plane_reset(struct drm_plane *plane)
 {
 	struct vop_win *win = to_vop_win(plane);
 	struct vop_plane_state *vop_plane_state =
@@ -1809,7 +1809,7 @@ void vop_atomic_plane_reset(struct drm_plane *plane)
 	plane->state->plane = plane;
 }
 
-struct drm_plane_state *
+static struct drm_plane_state *
 vop_atomic_plane_duplicate_state(struct drm_plane *plane)
 {
 	struct vop_plane_state *old_vop_plane_state;