diff --git a/[refs] b/[refs]
index a1115ace638b..f58a08a23f8d 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b342dd512f7af0e0e14e29c3e1f863150cfc46ff
+refs/heads/master: bd5d7ce9afdd0cddc5ab65e20d1134ccad824418
diff --git a/trunk/drivers/tty/tty_ldisc.c b/trunk/drivers/tty/tty_ldisc.c
index c5782294e532..e96d1876bd62 100644
--- a/trunk/drivers/tty/tty_ldisc.c
+++ b/trunk/drivers/tty/tty_ldisc.c
@@ -64,7 +64,9 @@ static void put_ldisc(struct tty_ldisc *ld)
 		return;
 	}
 	raw_spin_unlock_irqrestore(&tty_ldisc_lock, flags);
-	wake_up(&ld->wq_idle);
+
+	if (waitqueue_active(&ld->wq_idle))
+		wake_up(&ld->wq_idle);
 }
 
 /**