Re: [PATCH] ACPI / LPIT: Add Low Power Idle Table (LPIT) support

From: Srinivas Pandruvada
Date: Wed Oct 04 2017 - 21:27:22 EST


On Thu, 2017-10-05 at 02:51 +0200, Rafael J. Wysocki wrote:
> On Thu, Oct 5, 2017 at 2:39 AM, Srinivas Pandruvada
> <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote:
> >
> > On Thu, 2017-10-05 at 02:10 +0200, Rafael J. Wysocki wrote:
> > >
> > > On Thu, Oct 5, 2017 at 1:43 AM, Srinivas Pandruvada
> > > <srinivas.pandruvada@xxxxxxxxxxxxxxx> wrote:
> > > >
> > > >
> > > > Added functionality to read LPIT table, which provides:
> > > >
> > > > - Sysfs interface to read residency counters via
> > > > /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us
> > > > /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency
> > > > _us
> > > >
> > > >
> > [...]
> >
> > >
> > > >
> > > > +int lpit_read_residency_count_address(u64 *address)
> > > > +{
> > > > +ÂÂÂÂÂÂÂif (!residency_info_mem.gaddr.address)
> > > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂreturn -EINVAL;
> > > > +
> > > > +ÂÂÂÂÂÂÂ*address = residency_info_mem.gaddr.address;
> > > > +
> > > > +ÂÂÂÂÂÂÂreturn 0;
> > > > +}
> > > I don't see users of this.ÂÂAre there any?
> > The user will be pmc_core_driver which will go through platform x86
> > drivers tree.
> OK
>
> >
> > Also some mei drivers will also need.
> What for?
They also need to get the PMC base address.

[...]
> > > > +
> > > > +#endif
> > > > +#endif
> > > The above can go into internal.h or sleep.h in drivers/acpi/ IMO.
> > > There's not need to export it.
> > The pmc core driver is in drivers/platform/x86. Do you want to
> > include
> > a local file from there?
> So the _init() thing can go to internal.h and the one-line header of
> the other one can go to include/linux/acpi.h just fine.
OK.

>
> And it would be good to mention what is going to use it in the
> changelog.
It is already described in the change log for pmc core driver.

Thanks,
Srinivas