1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 8bbd8e29e60d..7b2e2420ecae 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -340,6 +340,9 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf)
 			acm->iocount.overrun++;
 		spin_unlock_irqrestore(&acm->read_lock, flags);
 
+		if (newctrl & ACM_CTRL_BRK)
+			tty_flip_buffer_push(&acm->port);
+
 		if (difference)
 			wake_up_all(&acm->wioctl);
 
@@ -475,11 +478,16 @@ static int acm_submit_read_urbs(struct acm *acm, gfp_t mem_flags)
 
 static void acm_process_read_urb(struct acm *acm, struct urb *urb)
 {
+	unsigned long flags;
+
 	if (!urb->actual_length)
 		return;
 
+	spin_lock_irqsave(&acm->read_lock, flags);
 	tty_insert_flip_string(&acm->port, urb->transfer_buffer,
 			urb->actual_length);
+	spin_unlock_irqrestore(&acm->read_lock, flags);
+
 	tty_flip_buffer_push(&acm->port);
 }
 
@@ -726,7 +734,8 @@ static void acm_port_destruct(struct tty_port *port)
 {
 	struct acm *acm = container_of(port, struct acm, port);
 
-	acm_release_minor(acm);
+	if (acm->minor != ACM_MINOR_INVALID)
+		acm_release_minor(acm);
 	usb_put_intf(acm->control);
 	kfree(acm->country_codes);
 	kfree(acm);
@@ -1323,8 +1332,10 @@ made_compressed_probe:
 	usb_get_intf(acm->control); /* undone in destruct() */
 
 	minor = acm_alloc_minor(acm);
-	if (minor < 0)
+	if (minor < 0) {
+		acm->minor = ACM_MINOR_INVALID;
 		goto err_put_port;
+	}
 
 	acm->minor = minor;
 	acm->dev = usb_dev;