From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751471AbWINI2b (ORCPT ); Thu, 14 Sep 2006 04:28:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751475AbWINI2b (ORCPT ); Thu, 14 Sep 2006 04:28:31 -0400 Received: from smtp103.biz.mail.mud.yahoo.com ([68.142.200.238]:46699 "HELO smtp103.biz.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1751471AbWINI2a (ORCPT ); Thu, 14 Sep 2006 04:28:30 -0400 Mime-Version: 1.0 (Apple Message framework v624) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <330177f4f8f83d0d39034c8f05d4b1f7@nomadgs.com> Content-Transfer-Encoding: 7bit Cc: kernel list From: Matthew Locke Subject: PowerOP summary Date: Thu, 14 Sep 2006 01:28:25 -0700 To: Greg KH , pm list X-Mailer: Apple Mail (2.624) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org As a result of some discussion during the Linux PM summit between myself, Todd Poynor, Dominik Brodowski, Mark Gross, Amit Kucheria and a few others, Eugeny and I have been working on getting a power management interface called PowerOP accepted. A good bit of discussion has occurred on linux-pm over the last couple months about PowerOP interfaces and why its needed. Here is a short summary requested by Greg: Summary PowerOP is an interface to create and select operating points. Operating points are a collection of platform specific system parameters (ie not i/o devices) that affect power consumption. These parameters include cpu frequency, voltages, clock sources and dividers and others. PowerOP provides a platform independent interface to control these platform specific parameters. This interface is a basic building block of a power management stack for advanced power management on embedded mobile devices. For those familiar with cpufreq, it can be viewed as a redesign of the cpufreq_driver layer to be platform independent and enable more advanced governors and policies on hardware with lots of power parameters. Developers Matthew Locke and Eugeny Mints are the main guys behind PowerOP now but many have contributed to get to this point. A few key points - PowerOP does not replace cpufreq - PowerOP authors and advocates are not suggesting to replace cpufreq - PowerOP is required for doing power management on embedded mobile devices - PowerOP patches are standalone and do not require integration with cpufreq or suspend/resume subsystems - PowerOP does not break anything including existing userspace interface and centrino code. We will resend the patches again for review and discussion. Each patch contains more detailed description. Matt and Eugeny