linux-kernel - Re: [PATCH] cpufreq / CPPC: Add cpuinfo_cur

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Date:   Wed, 23 May 2018 10:32:08 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     George Cherian <george.cherian@...ium.com>
Cc:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        rjw@...ysocki.net
Subject: Re: [PATCH] cpufreq / CPPC: Add cpuinfo_cur_freq support for CPPC

On 22-05-18, 04:42, 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@...ium.com>
> ---
>  drivers/cpufreq/cppc_cpufreq.c | 44 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 44 insertions(+)

Acked-by: Viresh Kumar <viresh.kumar@...aro.org>

-- 
viresh