Re: [PATCH v3 14/25] openrisc: Initial support for the idle state

From: Stafford Horne
Date: Wed Feb 22 2017 - 09:19:24 EST


On Tue, Feb 21, 2017 at 12:24:41PM -0800, Joe Perches wrote:
> On Wed, 2017-02-22 at 04:11 +0900, Stafford Horne wrote:
> > From: Sebastian Macke <sebastian@xxxxxxxx>
> >
> > This patch adds basic support for the idle state of the cpu.
> > The patch overrides the regular idle function, enables the interupts,
> > checks for the power management unit and enables the cpu doze mode
> > if available.
>
> trivia:
>
> > diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
> []
> > @@ -75,6 +75,20 @@ void machine_power_off(void)
> > __asm__("l.nop 1");
> > }
> >
> > +/*
> > + * Send the doze signal to the cpu if available.
> > + * Make sure, that all interrupts are enabled
> > + */
> > +void arch_cpu_idle(void)
> > +{
> > + unsigned long upr;
> > +
> > + local_irq_enable();
> > + upr = mfspr(SPR_UPR);
> > + if (upr & SPR_UPR_PMP)
> > + mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME);
> > +}
>
> Perhaps this would be easier to read without the automatic
>
> void arch_cpu_idle(void)
> {
> local_irq_enable();
> if (mfspr(SPR_UPR) & SPR_UPR_PMP)
> mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME);
> }

Yeah, that looks better. I made the change. Will post another series.