Hi,
On 02.06.2014 14:35, 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@samsung.com Acked-by: Kyungmin Park kyungmin.park@samsung.com
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 aeff99e..0fb9a5a 100644 --- a/arch/arm/mach-exynos/pm.c +++ b/arch/arm/mach-exynos/pm.c @@ -456,6 +456,10 @@ 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);
I wonder whether this isn't required on any Exynos SoC in general, as this mask decides which STANDBY_WFI/WFE signals are considered before entering the lower power state.
Also you should check the behavior with Krzysztof's patch adding support for delayed reset assertion, which should cause WFI/WFE signals of CPUs powered down to be kept asserted.
Best regards, Tomasz