diff --git a/[refs] b/[refs]
index b53103ab97c2..bdbcea341933 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6683549e4ba050cddd8fa88c3f1e53b825fdcb6d
+refs/heads/master: e9490e93c1978b6669f3e993caa3189be13ce459
diff --git a/trunk/drivers/tty/n_tty.c b/trunk/drivers/tty/n_tty.c
index 6259242b7858..8c0b7b42319c 100644
--- a/trunk/drivers/tty/n_tty.c
+++ b/trunk/drivers/tty/n_tty.c
@@ -1742,7 +1742,8 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 
 do_it_again:
 
-	BUG_ON(!tty->read_buf);
+	if (WARN_ON(!tty->read_buf))
+		return -EAGAIN;
 
 	c = job_control(tty, file);
 	if (c < 0)