diff --git a/[refs] b/[refs]
index 755b673fdb96..ca7658cd227b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 63d486964cbd0d8556f28bf215c37b0d63f6bbba
+refs/heads/master: 5d4121c04b3577e37e389b3553d442f44bb346d7
diff --git a/trunk/drivers/tty/tty_io.c b/trunk/drivers/tty/tty_io.c
index 28c3e869ebba..41e42f13a214 100644
--- a/trunk/drivers/tty/tty_io.c
+++ b/trunk/drivers/tty/tty_io.c
@@ -1415,6 +1415,10 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
 	if (!tty->port)
 		tty->port = driver->ports[idx];
 
+	WARN_RATELIMIT(!tty->port,
+			"%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
+			__func__, tty->driver->name);
+
 	/*
 	 * Structures all installed ... call the ldisc open routines.
 	 * If we fail here just call release_tty to clean up.  No need