diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index bd85e32521d2..10605ecc99ab 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -212,8 +212,9 @@ void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
 {
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 	unsigned int mode;
+	unsigned long flags;
 
-	spin_lock(&port->lock);
+	spin_lock_irqsave(&port->lock, flags);
 
 	/* Disable interrupts */
 	UART_PUT_IDR(port, atmel_port->tx_done_mask);
@@ -244,7 +245,7 @@ void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf)
 	/* Enable interrupts */
 	UART_PUT_IER(port, atmel_port->tx_done_mask);
 
-	spin_unlock(&port->lock);
+	spin_unlock_irqrestore(&port->lock, flags);
 
 }