Re: [PATCH v6 4/5] arm64: add support for ACPI Low Power Idle(LPI)

[Sudeep Holla]

Hi, Daniel,

On 24/06/16 22:04, Daniel Lezcano wrote:

[...]

> > > +
> > > +    psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
> > > +    if (!psci_states)
> > > +        return -ENOMEM;
> > > +
> > > +    for (i = 0; i < count; i++) {
> > > +        u32 state;
> > > +
> > > +        lpi = &pr->power.lpi_states[i + 1];
> > > +        state = lpi->address & 0xFFFFFFFF;
>
> Why is needed to mask 'address' ?

This is as per Section 3.1.1 FFH Usage in LPI state entry methods in [1]

[...]

> > >   int psci_cpu_init_idle(unsigned int cpu)
> > >   {
> > >       struct device_node *cpu_node;
> > >       int ret;
> > >
> > > +    if (!acpi_disabled)
> > > +        return psci_acpi_cpu_init_idle(cpu);
>
> Is it possible the case where there is information in both the DT and in
> ACPI ? So ACPI is enabled without idle information which is in the DT ?

No, as Rafael mentioned aready.

> > Either you do this, or we have to add it somehow somewhere in
> > drivers/cpuidle to avoid duplicating it.
> >
> > @Daniel: do you have an opinion on this please ?
>
> Yes, this function should be added to avoid duplication.

So, I assume you are happy with the way it's handled in this patch ?
(I will rename the file as suggested by Lorenzo)

--
Regards,
Sudeep

[1] 
http://infocenter.arm.com/help/topic/com.arm.doc.den0048a/DEN0048A_ARM_FFH_Specification.pdf