tty: tty port zero baud open

If we have no speed set at some point then we should not raise DTR/RTS at
that point when opening as the tty is not ready

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index ff94182b3813..0723664fe0ab 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -216,7 +216,8 @@ int tty_port_block_til_ready(struct tty_port *port,
 
         while (1) {
                 /* Indicate we are open */
-                tty_port_raise_dtr_rts(port);
+                if (tty->termios->c_cflag & CBAUD)
+                        tty_port_raise_dtr_rts(port);
 
                 set_current_state(TASK_INTERRUPTIBLE);
                 /* Check for a hangup or uninitialised port. Return accordingly */