USB: cdc-acm tell tty layer not to split things up.

It ensures that the tty level do not split
the send buffer into 2KB blocks.


Signed-off-by: David Engraf <david.engraf@netcom.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 0147ea3..1ded83b 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -489,6 +489,7 @@
 	else
 		rv = 0;
 
+	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
 	tty->driver_data = acm;
 	acm->tty = tty;