serial: bfin_5xx: grab port lock before making port termios changes

The port lock exists to protect these resources, so we need to grab it
before making changes.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/serial/bfin_5xx.c

@@ -849,6 +849,8 @@ bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (termios->c_cflag & CMSPAR)
 		lcr |= STP;
 
+	spin_lock_irqsave(&uart->port.lock, flags);
+
 	port->read_status_mask = OE;
 	if (termios->c_iflag & INPCK)
 		port->read_status_mask |= (FE | PE);
@@ -878,8 +880,6 @@ bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (termios->c_line != N_IRDA)
 		quot -= ANOMALY_05000230;
 
-	spin_lock_irqsave(&uart->port.lock, flags);
-
 	UART_SET_ANOMALY_THRESHOLD(uart, USEC_PER_SEC / baud * 15);
 
 	/* Disable UART */