serial: fix termios settings in open

Move termios initialization in open into uart_dtr_rts to make sure
it always gets called when necessary. Based on a suggestion from
Alan Cox.

Alan writes:
Ok this sort of makes sense. Something isn't getting initialised and both
getty and minicom will do a termios set which is sorting it out.
This is occurring because the generic block_til_ready sets
ASYNCB_NORMAL_ACTIVE so the termios updating gets skipped.

This patch should cure it and then we can think about doing it more
elegantly by getting the serial layer to use tty_port_open, kfifo and
the like and removing the tons of repeated crap in all the drivers.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Tony Luck <tony.luck@intel.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 9 insertions, 10 deletions

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index a55751a12c38..3d2acc2265f7 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1520,8 +1520,16 @@ static void uart_dtr_rts(struct tty_port *port, int onoff)
         struct uart_state *state = container_of(port, struct uart_state, port);
         struct uart_port *uport = state->uart_port;
 
-        if (onoff)
+        if (onoff) {
                 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+
+                /*
+                 * If this is the first open to succeed,
+                 * adjust things to suit.
+                 */
+                if (!test_and_set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags))
+                        uart_update_termios(port->tty, state);
+        }
         else
                 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
 }
@@ -1636,15 +1644,6 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
         if (retval == 0)
                 retval = tty_port_block_til_ready(port, tty, filp);
 
-        /*
-         * If this is the first open to succeed, adjust things to suit.
-         */
-        if (retval == 0 && !(port->flags & ASYNC_NORMAL_ACTIVE)) {
-                set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
-
-                uart_update_termios(tty, state);
-        }
-
 fail:
         return retval;
 }