[SERIAL] Fix serial console resume

Don't use uart_change_speed() when trying to restore the serial
console settings - the port may not have a tty associated with
it.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>

1 files changed, 15 insertions, 1 deletions

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 5ed45a7cbdda..16c227d30016 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1877,7 +1877,21 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
 	 * Re-enable the console device after suspending.
 	 */
 	if (uart_console(port)) {
-		uart_change_speed(state, NULL);
+		struct termios termios;
+
+		/*
+		 * First try to use the console cflag setting.
+		 */
+		memset(&termios, 0, sizeof(struct termios));
+		termios.c_cflag = port->cons->cflag;
+
+		/*
+		 * If that's unset, use the tty termios setting.
+		 */
+		if (state->info && state->info->tty && termios.c_cflag == 0)
+			termios = *state->info->tty->termios;
+
+		port->ops->set_termios(port, &termios, NULL);
 		console_start(port->cons);
 	}