serdev: ttyport: ignore carrier detect to avoid hangups

Serdev currently does not support hangups so make sure to set CLOCAL to
prevent loss of carrier from triggering one.

Note however that not all tty drivers honour CLOCAL.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index f76a8e044e4ef3b10e121b56de32726b3856926a..75f312ed96e8493cd986e89386d12d671f526128 100644 (file)
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -115,6 +115,8 @@ static int ttyport_open(struct serdev_controller *ctrl)
        ktermios.c_cflag &= ~(CSIZE | PARENB);
        ktermios.c_cflag |= CS8;
        ktermios.c_cflag |= CRTSCTS;
+       /* Hangups are not supported so make sure to ignore carrier detect. */
+       ktermios.c_cflag |= CLOCAL;
        tty_set_termios(tty, &ktermios);
 
        set_bit(SERPORT_ACTIVE, &serport->flags);