diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index f64c475a1379..ba053a68529f 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1582,13 +1582,6 @@ static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
 	    container_of(port, struct uart_amba_port, port);
 	unsigned int cr;
 
-	if (port->rs485.flags & SER_RS485_ENABLED) {
-		if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
-			mctrl &= ~TIOCM_RTS;
-		else
-			mctrl |= TIOCM_RTS;
-	}
-
 	cr = pl011_read(uap, REG_CR);
 
 #define	TIOCMBIT(tiocmbit, uartbit)		\
@@ -1812,14 +1805,8 @@ static int pl011_startup(struct uart_port *port)
 	cr &= UART011_CR_RTS | UART011_CR_DTR;
 	cr |= UART01x_CR_UARTEN | UART011_CR_RXE;
 
-	if (port->rs485.flags & SER_RS485_ENABLED) {
-		if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
-			cr &= ~UART011_CR_RTS;
-		else
-			cr |= UART011_CR_RTS;
-	} else {
+	if (!(port->rs485.flags & SER_RS485_ENABLED))
 		cr |= UART011_CR_TXE;
-	}
 
 	pl011_write(cr, uap, REG_CR);
 
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index dc40c4155356..0db90be4c3bc 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -144,6 +144,11 @@ uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
 	unsigned long flags;
 	unsigned int old;
 
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		set &= ~TIOCM_RTS;
+		clear &= ~TIOCM_RTS;
+	}
+
 	spin_lock_irqsave(&port->lock, flags);
 	old = port->mctrl;
 	port->mctrl = (old & ~clear) | set;
@@ -157,23 +162,10 @@ uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
 
 static void uart_port_dtr_rts(struct uart_port *uport, int raise)
 {
-	int rs485_on = uport->rs485_config &&
-		(uport->rs485.flags & SER_RS485_ENABLED);
-	int RTS_after_send = !!(uport->rs485.flags & SER_RS485_RTS_AFTER_SEND);
-
-	if (raise) {
-		if (rs485_on && RTS_after_send) {
-			uart_set_mctrl(uport, TIOCM_DTR);
-			uart_clear_mctrl(uport, TIOCM_RTS);
-		} else {
-			uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
-		}
-	} else {
-		unsigned int clear = TIOCM_DTR;
-
-		clear |= (!rs485_on || RTS_after_send) ? TIOCM_RTS : 0;
-		uart_clear_mctrl(uport, clear);
-	}
+	if (raise)
+		uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+	else
+		uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
 }
 
 /*
@@ -1075,11 +1067,6 @@ uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
 		goto out;
 
 	if (!tty_io_error(tty)) {
-		if (uport->rs485.flags & SER_RS485_ENABLED) {
-			set &= ~TIOCM_RTS;
-			clear &= ~TIOCM_RTS;
-		}
-
 		uart_update_mctrl(uport, set, clear);
 		ret = 0;
 	}
@@ -2390,6 +2377,9 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 		 */
 		spin_lock_irqsave(&port->lock, flags);
 		port->mctrl &= TIOCM_DTR;
+		if (port->rs485.flags & SER_RS485_ENABLED &&
+		    !(port->rs485.flags & SER_RS485_RTS_AFTER_SEND))
+			port->mctrl |= TIOCM_RTS;
 		port->ops->set_mctrl(port, port->mctrl);
 		spin_unlock_irqrestore(&port->lock, flags);