From c93f09402106f22601838ee2bb0d02bae934b5e5 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 7 Apr 2010 16:49:31 -0700 Subject: caif: check write operations write is optional for a tty device. Check that we have a write op rather than calling NULL. Signed-off-by: Alan Cox Signed-off-by: David S. Miller --- drivers/net/caif/caif_serial.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c index 3502f607117f..c669ec37483b 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -312,6 +312,10 @@ static int ldisc_open(struct tty_struct *tty) char name[64]; int result; + /* No write no play */ + if (tty->ops->write == NULL) + return -EOPNOTSUPP; + sprintf(name, "cf%s", tty->name); dev = alloc_netdev(sizeof(*ser), name, caifdev_setup); ser = netdev_priv(dev); -- cgit v1.2.3