From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Brandewie Subject: Re: [PATCH v3 1/2] CPPC as a PID controller backend Date: Mon, 01 Dec 2014 06:56:17 -0800 Message-ID: <547C8191.4030002@gmail.com> References: <1416429381-3839-1-git-send-email-ashwin.chaugule@linaro.org> <1416429381-3839-2-git-send-email-ashwin.chaugule@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pa0-f43.google.com ([209.85.220.43]:57592 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753744AbaLAO4P (ORCPT ); Mon, 1 Dec 2014 09:56:15 -0500 Received: by mail-pa0-f43.google.com with SMTP id kx10so11271020pab.30 for ; Mon, 01 Dec 2014 06:56:14 -0800 (PST) In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar , Ashwin Chaugule , "Rafael J. Wysocki" Cc: dirk.brandewie@gmail.com, "rwells@codeaurora.org" , Linda Knippers , "linux-pm@vger.kernel.org" , Catalin Marinas , Patch Tracking , "linaro-acpi@lists.linaro.org" On 11/30/2014 10:26 PM, Viresh Kumar wrote: > On 1 December 2014 at 11:53, Ashwin Chaugule wrote: >> On 19 November 2014 at 15:36, Ashwin Chaugule >> wrote: >>> CPPC (Collaborative Processor Performance Control) is defined >>> in the ACPI 5.0+ spec. It is a method for controlling CPU >>> performance on a continuous scale using performance feedback >>> registers. In contrast to the legacy "pstate" scale which is >>> discretized, and tied to CPU frequency, CPPC works off of an >>> abstract continuous scale. This lets the platforms freely interpret >>> the abstract unit and optimize it for power and performance given >>> its knowledge of thermal budgets and other constraints. >>> >>> The PID governor operates on similar concepts and can use CPPC >>> semantics to acquire the information it needs. This information >>> may be provided by various platforms via MSRs, CP15s or memory >>> mapped registers. CPPC helps to wrap all these variations into a >>> common framework. >>> >>> This patch introduces CPPC using PID as its governor for CPU >>> performance management. >>> >>> Signed-off-by: Ashwin Chaugule >>> --- >>> drivers/cpufreq/Kconfig | 12 + >>> drivers/cpufreq/Makefile | 1 + >>> drivers/cpufreq/acpi_pid.c | 1156 ++++++++++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 1169 insertions(+) >>> create mode 100644 drivers/cpufreq/acpi_pid.c >> >> >> Ping. >> >> Any comments on these patches? > > Redirecting the Ping to Rafael/Dirk :) > Ashwin has incorporated my feedback. I have no issues --Dirk