diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c
index 8f2bc6a28482..3261f142baea 100644
--- a/drivers/gpu/drm/drm_encoder.c
+++ b/drivers/gpu/drm/drm_encoder.c
@@ -129,6 +129,7 @@ static int __drm_encoder_init(struct drm_device *dev,
 	}
 
 	INIT_LIST_HEAD(&encoder->bridge_chain);
+	mutex_init(&encoder->bridge_chain_mutex);
 	list_add_tail(&encoder->head, &dev->mode_config.encoder_list);
 	encoder->index = dev->mode_config.num_encoder++;
 
@@ -202,6 +203,7 @@ void drm_encoder_cleanup(struct drm_encoder *encoder)
 	kfree(encoder->name);
 	list_del(&encoder->head);
 	dev->mode_config.num_encoder--;
+	mutex_destroy(&encoder->bridge_chain_mutex);
 
 	memset(encoder, 0, sizeof(*encoder));
 }
diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h
index 977a9381c8ba..eded7c34481a 100644
--- a/include/drm/drm_encoder.h
+++ b/include/drm/drm_encoder.h
@@ -25,6 +25,7 @@
 
 #include <linux/list.h>
 #include <linux/ctype.h>
+#include <linux/mutex.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_mode.h>
 #include <drm/drm_mode_object.h>
@@ -189,6 +190,9 @@ struct drm_encoder {
 	 */
 	struct list_head bridge_chain;
 
+	/** @bridge_chain_mutex: protect bridge_chain from changes while iterating */
+	struct mutex bridge_chain_mutex;
+
 	const struct drm_encoder_funcs *funcs;
 	const struct drm_encoder_helper_funcs *helper_private;