diff --git a/[refs] b/[refs]
index fba09b76a52b..a7497bddb274 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 354ab8567ae3107a8cbe7228c3181990ba598aac
+refs/heads/master: 6c4707f3f8c44ec18282e1c014c80e1c257042f9
diff --git a/trunk/drivers/usb/class/cdc-acm.c b/trunk/drivers/usb/class/cdc-acm.c
index f2a120eea9d4..36a2a0b7b82c 100644
--- a/trunk/drivers/usb/class/cdc-acm.c
+++ b/trunk/drivers/usb/class/cdc-acm.c
@@ -567,6 +567,14 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
 
 	usb_autopm_put_interface(acm->control);
 
+	/*
+	 * Unthrottle device in case the TTY was closed while throttled.
+	 */
+	spin_lock_irq(&acm->read_lock);
+	acm->throttled = 0;
+	acm->throttle_req = 0;
+	spin_unlock_irq(&acm->read_lock);
+
 	if (acm_submit_read_urbs(acm, GFP_KERNEL))
 		goto error_submit_read_urbs;