TTY: fix DTR being raised on hang up

Make sure to check ASYNC_INITIALISED before raising DTR when waking up
from blocked open in tty_port_block_til_ready.

Currently DTR could get raised at hang up as a blocked process would
raise DTR unconditionally before checking for hang up and returning.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 73bc1d9..7e3eaf4 100644 (file)
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -388,7 +388,7 @@ int tty_port_block_til_ready(struct tty_port *port,
 
        while (1) {
                /* Indicate we are open */
-               if (tty->termios.c_cflag & CBAUD)
+               if (C_BAUD(tty) && test_bit(ASYNCB_INITIALIZED, &port->flags))
                        tty_port_raise_dtr_rts(port);
 
                prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);