diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
index 6eac26649009d74afe077a392eb427f5dd81733d..f27c621a9297f3c896b84c9ea700d6285ef6b94f 100644
--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -1629,7 +1629,7 @@ static void change_port_settings(struct tty_struct *tty,
 		mos7720_port->shadowMCR |= (UART_MCR_XONANY);
 		/* To set hardware flow control to the specified *
 		 * serial port, in SP1/2_CONTROL_REG             */
-		if (port->number)
+		if (port_number)
 			write_mos_reg(serial, dummy, SP_CONTROL_REG, 0x01);
 		else
 			write_mos_reg(serial, dummy, SP_CONTROL_REG, 0x02);