[PATCH 2/2] Add kref to fake tty used by USB console

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

From: Kevin Hao <kexin.hao@windriver.com>

We alloc a fake tty in usb serial console setup function. we should
init the tty's kref otherwise we will face WARN_ON after following
invoke of tty_port_tty_set --> tty_kref_get.

Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
Signed-off-by: Alan Cox <alan@redhat.com>
---

 drivers/usb/serial/console.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)


diff --git a/drivers/usb/serial/console.c b/drivers/usb/serial/console.c
index 5b20de1..5b95009 100644
--- a/drivers/usb/serial/console.c
+++ b/drivers/usb/serial/console.c
@@ -135,6 +135,7 @@ static int usb_console_setup(struct console *co, char *options)
 				err("no more memory");
 				goto reset_open_count;
 			}
+			kref_init(&tty->kref);
 			termios = kzalloc(sizeof(*termios), GFP_KERNEL);
 			if (!termios) {
 				retval = -ENOMEM;