diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index c084cad..aca2bc5 100644
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -102,11 +102,12 @@ static void radeon_dp_work_func(struct work_struct *work)
 	struct drm_mode_config *mode_config = &dev->mode_config;
 	struct drm_connector *connector;
 
-	/* this should take a mutex */
+       mutex_lock(&mode_config->mutex);
 	if (mode_config->num_connector) {
 		list_for_each_entry(connector, &mode_config->connector_list, head)
 			radeon_connector_hotplug(connector);
 	}
+       mutex_unlock(&mode_config->mutex);
 }
 /**
  * radeon_driver_irq_preinstall_kms - drm irq preinstall callback