diff --git a/[refs] b/[refs]
index 093b42614027..69c0cb986287 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 42dd2aa6496a2e87e496aac5494d2e1d6096c85b
+refs/heads/master: 922b13565b6a826a925f9f91f053dc9cb0d6210e
diff --git a/trunk/drivers/usb/class/cdc-acm.c b/trunk/drivers/usb/class/cdc-acm.c
index 02eb60bb6795..3f1045993474 100644
--- a/trunk/drivers/usb/class/cdc-acm.c
+++ b/trunk/drivers/usb/class/cdc-acm.c
@@ -677,7 +677,7 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
 
 	/* Perform the closing process and see if we need to do the hardware
 	   shutdown */
-	if (tty_port_close_start(&acm->port, tty, filp) == 0)
+	if (!acm || tty_port_close_start(&acm->port, tty, filp) == 0)
 		return;
 	acm_port_down(acm, 0);
 	tty_port_close_end(&acm->port, tty);