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Commit 829dd811 authored by Haavard Skinnemoen's avatar Haavard Skinnemoen Committed by Linus Torvalds
Browse files

atmel_serial: use cpu_relax() when busy-waiting 



Replace two instances of barrier() with cpu_relax() since that's the right
thing to do when busy-waiting.  This does not actually change anything since
cpu_relax() is defined as barrier() on both ARM and AVR32.

Signed-off-by: default avatarHaavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: default avatarAndrew Victor <linux@maxim.org.za>
Tested-by: default avatarMarc Pignat <marc.pignat@hevs.ch>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b843aa21

drivers/serial/atmel_serial.c

+2 −2
Original line number Diff line number Diff line
@@ -615,7 +615,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, 
	imr = UART_GET_IMR(port);

	UART_PUT_IDR(port, -1);

	while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY))

		barrier();

		cpu_relax();



	/* disable receiver and transmitter */

	UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
@@ -794,7 +794,7 @@ void __init atmel_register_uart_fns(struct atmel_port_fns *fns) 
static void atmel_console_putchar(struct uart_port *port, int ch)

{

	while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))

		barrier();

		cpu_relax();

	UART_PUT_CHAR(port, ch);

}