diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 87876198801d405bbb61301c698bc69a6e16e415..16f271e21b9ce1c8005ce20028fa8877bf4eddf0 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1536,9 +1536,11 @@ bool drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
 
 	drm_fb_helper_parse_command_line(fb_helper);
 
+	mutex_lock(&dev->mode_config.mutex);
 	count = drm_fb_helper_probe_connector_modes(fb_helper,
 						    dev->mode_config.max_width,
 						    dev->mode_config.max_height);
+	mutex_unlock(&dev->mode_config.mutex);
 	/*
 	 * we shouldn't end up with no modes here.
 	 */