diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index e9b15c3746fa..a81ff7bc5fa1 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -1217,12 +1217,6 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
 	}
 #endif
 
-#ifdef CONFIG_SERIAL_8250_AU1X00
-	/* if access method is AU, it is a 16550 with a quirk */
-	if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU)
-		up->bugs |= UART_BUG_NOMSR;
-#endif
-
 	serial_outp(up, UART_LCR, save_lcr);
 
 	if (up->capabilities != uart_config[up->port.type].flags) {
@@ -2428,7 +2422,7 @@ serial8250_pm(struct uart_port *port, unsigned int state,
 static unsigned int serial8250_port_size(struct uart_8250_port *pt)
 {
 	if (pt->port.iotype == UPIO_AU)
-		return 0x100000;
+		return 0x1000;
 #ifdef CONFIG_ARCH_OMAP
 	if (is_omap_port(pt))
 		return 0x16 << pt->port.regshift;
@@ -2585,6 +2579,13 @@ static void serial8250_config_port(struct uart_port *port, int flags)
 
 	if (flags & UART_CONFIG_TYPE)
 		autoconfig(up, probeflags);
+
+#ifdef CONFIG_SERIAL_8250_AU1X00
+	/* if access method is AU, it is a 16550 with a quirk */
+	if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU)
+		up->bugs |= UART_BUG_NOMSR;
+#endif
+
 	if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
 		autoconfig_irq(up);