Commit 19386b32 authored by Russell King - ARM Linux's avatar Russell King - ARM Linux Committed by Dan Williams
Browse files

ARM: PL08x: ensure loops use cpu_relax() 



Tight loops should use cpu_relax() to allow CPUs to reduce power
consumption while waiting for events.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: default avatarLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 8c8cc2b1

drivers/dma/amba-pl08x.c

+3 −3
Original line number Diff line number Diff line
@@ -191,7 +191,7 @@ static void pl08x_set_cregs(struct pl08x_driver_data *pl08x, 
{

	/* Wait for channel inactive */

	while (pl08x_phy_channel_busy(ch))

		;

		cpu_relax();



	dev_vdbg(&pl08x->adev->dev,

		"WRITE channel %d: csrc=0x%08x, cdst=0x%08x, "
@@ -255,7 +255,7 @@ static void pl08x_enable_phy_chan(struct pl08x_driver_data *pl08x, 
	 * Do not access config register until channel shows as disabled

	 */

	while (readl(pl08x->base + PL080_EN_CHAN) & (1 << ch->id))

		;

		cpu_relax();



	/*

	 * Do not access config register until channel shows as inactive
@@ -288,7 +288,7 @@ static void pl08x_pause_phy_chan(struct pl08x_phy_chan *ch) 


	/* Wait for channel inactive */

	while (pl08x_phy_channel_busy(ch))

		;

		cpu_relax();

}



static void pl08x_resume_phy_chan(struct pl08x_phy_chan *ch)