Re: [PATCH v4] cpufreq / CPPC: Add cpuinfo_cur_freq support for CPPC
From: Rafael J. Wysocki
Date: Thu Jul 19 2018 - 06:48:01 EST
On Saturday, July 14, 2018 12:20:43 AM CEST Prakash, Prashanth wrote:
> Hi George,
>
> This version looks good. Thanks!
>
> On 7/12/2018 12:07 AM, George Cherian wrote:
> > Per Section 8.4.7.1.3 of ACPI 6.2, The platform provides performance
> > feedback via set of performance counters. To determine the actual
> > performance level delivered over time, OSPM may read a set of
> > performance counters from the Reference Performance Counter Register
> > and the Delivered Performance Counter Register.
> >
> > OSPM calculates the delivered performance over a given time period by
> > taking a beginning and ending snapshot of both the reference and
> > delivered performance counters, and calculating:
> >
> > delivered_perf = reference_perf X (delta of delivered_perf counter / delta of reference_perf counter).
> >
> > Implement the above and hook this to the cpufreq->get method.
> >
> > Signed-off-by: George Cherian <george.cherian@xxxxxxxxxx>
> > Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> Acked-by: Prashanth Prakash <pprakash@xxxxxxxxxxxxxx>
>
Patch applied, thanks!