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

[Daniel Lezcano]

On 06/02/2014 02:08 PM, Bartlomiej Zolnierkiewicz wrote:
> Hi,
>
> On Friday, May 16, 2014 11:03:11 AM Daniel Lezcano wrote:
> > 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() ?
>
> I would prefer to keep this code close to exynos_pm_central_suspend()
> because exynos_pm_suspend() (which calls exynos_pm_central_suspend()
> too) also contains S5P_USE_STANDBY_WF[I,E]0 setting code (done for all
> SoCs).  If possible I would like to make this code common for AFTR &
> suspend in the future (once it is tested on Exynos4210 and Exynos5250)
> by moving S5P_USE_STANDBY_WF[I,E]0 setting to exynos_pm_central_suspend()
> and doing it for all SoCs.  Are you okay with this?

Yeah, no problem.


> > >    			exynos_cpu_save_register();
> > >    		}
> > >    		break;
>
> Best regards,
> --
> Bartlomiej Zolnierkiewicz
> Samsung R&D Institute Poland
> Samsung Electronics


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