s/barrier/cpu_relax/

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/serial/atmel_serial.c

@@ -1217,7 +1217,7 @@ static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser)
 static int atmel_poll_get_char(struct uart_port *port)
 {
 	while (!(UART_GET_CSR(port) & ATMEL_US_RXRDY))
-		barrier();
+		cpu_relax();
 
 	return UART_GET_CHAR(port);
 }
@@ -1225,7 +1225,7 @@ static int atmel_poll_get_char(struct uart_port *port)
 static void atmel_poll_put_char(struct uart_port *port, unsigned char ch)
 {
 	while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))
-		barrier();
+		cpu_relax();
 
 	UART_PUT_CHAR(port, ch);
 }