From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932407AbVI3A3H (ORCPT ); Thu, 29 Sep 2005 20:29:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932410AbVI3A3H (ORCPT ); Thu, 29 Sep 2005 20:29:07 -0400 Received: from gate.crashing.org ([63.228.1.57]:33921 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S932407AbVI3A3F (ORCPT ); Thu, 29 Sep 2005 20:29:05 -0400 Subject: Re: iMac G5: experimental thermal & cpufreq support From: Benjamin Herrenschmidt To: Geoff Levand Cc: linuxppc64-dev@ozlabs.org, linuxppc-dev list , "debian-powerpc@lists.debian.org" , Linux Kernel list In-Reply-To: <433C7882.20000@am.sony.com> References: <1127978432.6102.53.camel@gaston> <433C7882.20000@am.sony.com> Content-Type: text/plain Date: Fri, 30 Sep 2005 10:26:59 +1000 Message-Id: <1128040019.31197.3.camel@gaston> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2005-09-29 at 16:28 -0700, Geoff Levand wrote: > Benjamin Herrenschmidt wrote: > > The algorithm itself is extracted from darwin. However, it's a rather > > complex modified version of the PID algorithm, and thus it could use > > some review to make sure I got everything right. > > > > As we are already in the digital domain, I would think it would be > more savvy to use a digital controller than try to simulate an > analog controller... Why don't you abstract the control algorithm > such that you can plug in others as they are developed. Because I don't know much about those control algorithms, and all the calibration data provided by the firmware is in the form of factors for these algorithms, I wouldn't know how to "unmangle" them to use with different ones. Actually, the control algorithms (PID and modified PID) are in a "helper", so it's fairly easy for the platform module to use whatever it wants, feel free to submit other algorithms :) But for Apple machines, I'd rather use what I have calibration data for, unless you can produce something that works without any... Ben.