Re: [PATCH 03/14] powerpc/64s: idle provide a default idle for POWER9

[Nicholas Piggin <npiggin@gmail.com>]

On Mon, 12 Jun 2017 14:23:16 +0530
Gautham R Shenoy <ego@linux.vnet.ibm.com> wrote:

> Hi Nick,
> 
> On Mon, Jun 12, 2017 at 09:58:24AM +1000, Nicholas Piggin wrote:
> > Before the cpuidle driver is enabled, provide a default idle
> > function similarly to POWER7/8.
> > 
> > This should not have much effect, because the cpuidle driver
> > for powernv is mandatory, but if that changes we should have
> > a fallback.
> > 
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > ---
> >  arch/powerpc/platforms/powernv/idle.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
> > index f188d84d9c59..e327e1585ddc 100644
> > --- a/arch/powerpc/platforms/powernv/idle.c
> > +++ b/arch/powerpc/platforms/powernv/idle.c
> > @@ -677,6 +677,8 @@ static int __init pnv_init_idle_states(void)
> > 
> >  	if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED)
> >  		ppc_md.power_save = power7_idle;
> > +	else if (supported_cpuidle_states & OPAL_PM_STOP_INST_FAST)
> > +		ppc_md.power_save = power9_idle;  
> 
> We are already initializing this in pnv_power9_idle_init() depending
> on whether the device tree has exposed at least one INST_FAST idle
> state. Else this should be NULL, because the firmware doesn't want us
> to use a platform idle state!

Ah I missed that, thanks. Will drop this one.

Thanks,
Nick