diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
index 251f0018ae8c..dba5950b8d0e 100644
--- a/drivers/tty/serial/8250/8250_fintek.c
+++ b/drivers/tty/serial/8250/8250_fintek.c
@@ -200,12 +200,12 @@ static int fintek_8250_rs485_config(struct uart_port *port,
 	if (!pdata)
 		return -EINVAL;
 
-	/* Hardware do not support same RTS level on send and receive */
-	if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
-			!(rs485->flags & SER_RS485_RTS_AFTER_SEND))
-		return -EINVAL;
 
 	if (rs485->flags & SER_RS485_ENABLED) {
+		/* Hardware do not support same RTS level on send and receive */
+		if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
+		    !(rs485->flags & SER_RS485_RTS_AFTER_SEND))
+			return -EINVAL;
 		memset(rs485->padding, 0, sizeof(rs485->padding));
 		config |= RS485_URA;
 	} else {