Re: [PATCH 6/7] ARM: EXYNOS: PM: fix register setup on EXYNOS4x12 for AFTR mode code

From: Daniel Lezcano
Date: Fri May 16 2014 - 05:03:11 EST


On 05/05/2014 12:57 PM, Bartlomiej Zolnierkiewicz wrote:
Add S5P_CENTRAL_SEQ_OPTION register setup for EXYNOS4x12 to AFTR
mode code. Without this setup AFTR mode doesn't show any benefit
over WFI one. When this setup is applied AFTR mode reduces power
consumption by ~12% (as measured on Trats2 board).

This change is a preparation for adding secure firmware support to
EXYNOS cpuidle driver.

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
---
arch/arm/mach-exynos/pm.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
index 18f6bf8..3922968 100644
--- a/arch/arm/mach-exynos/pm.c
+++ b/arch/arm/mach-exynos/pm.c
@@ -391,6 +391,10 @@ static int exynos_cpu_pm_notifier(struct notifier_block *self,
case CPU_PM_ENTER:
if (cpu == 0) {
exynos_pm_central_suspend();
+ if (soc_is_exynos4212() || soc_is_exynos4412())
+ __raw_writel(S5P_USE_STANDBY_WFI0 |
+ S5P_USE_STANDBY_WFE0,
+ S5P_CENTRAL_SEQ_OPTION);

Why not put this code in the exynos_enter_aftr() ?

exynos_cpu_save_register();
}
break;



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