diff --git a/[refs] b/[refs]
index aaf01618fc2c..b0c079fe5518 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 454459b02ea9c8e850fd0b4e770037daf9a7b758
+refs/heads/master: 28d1dfadd3ca07e7ec1c3de4f82ac2b8ece4be91
diff --git a/trunk/drivers/usb/class/cdc-acm.c b/trunk/drivers/usb/class/cdc-acm.c
index 0147ea39340e..1ded83b66af0 100644
--- a/trunk/drivers/usb/class/cdc-acm.c
+++ b/trunk/drivers/usb/class/cdc-acm.c
@@ -489,6 +489,7 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
 	else
 		rv = 0;
 
+	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
 	tty->driver_data = acm;
 	acm->tty = tty;