From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Prakash, Prashanth" Subject: Re: [PATCH v4] cpufreq / CPPC: Add cpuinfo_cur_freq support for CPPC Date: Fri, 13 Jul 2018 16:20:43 -0600 Message-ID: <41a6e3c7-db85-9ff1-daf4-07569c11fc8c@codeaurora.org> References: <1531375675-52623-1-git-send-email-george.cherian@cavium.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1531375675-52623-1-git-send-email-george.cherian@cavium.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: George Cherian , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Cc: viresh.kumar@linaro.org, rjw@rjwysocki.net List-Id: linux-pm@vger.kernel.org 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 > Acked-by: Viresh Kumar Acked-by: Prashanth Prakash