diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 08b8aa5299b5..32da5a4182ac 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -558,10 +558,8 @@ static void acm_softint(struct work_struct *work)
 		clear_bit(EVENT_RX_STALL, &acm->flags);
 	}
 
-	if (test_bit(EVENT_TTY_WAKEUP, &acm->flags)) {
+	if (test_and_clear_bit(EVENT_TTY_WAKEUP, &acm->flags))
 		tty_port_tty_wakeup(&acm->port);
-		clear_bit(EVENT_TTY_WAKEUP, &acm->flags);
-	}
 }
 
 /*