--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -531,8 +531,8 @@
 	tasklet_schedule(&acm->urb_task);
 
 done:
-err_out:
 	mutex_unlock(&acm->mutex);
+err_out:
 	mutex_unlock(&open_mutex);
 	return rv;