Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964987AbWILD5R (ORCPT ); Mon, 11 Sep 2006 23:57:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964993AbWILD5R (ORCPT ); Mon, 11 Sep 2006 23:57:17 -0400 Received: from mail.kroah.org ([69.55.234.183]:41179 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S964987AbWILD5R (ORCPT ); Mon, 11 Sep 2006 23:57:17 -0400 Date: Mon, 11 Sep 2006 20:37:00 -0700 From: Greg KH To: Mark Gross Cc: Pavel Machek , kernel list , "Eugeny S. Mints" , Matthew Locke , Amit Kucheria , pm list , Preece Scott-PREECE , Igor Stoppa Subject: Re: cpufreq terminally broken [was Re: community PM requirements/issues and PowerOP] Message-ID: <20060912033700.GD27397@kroah.com> References: <450516E8.9010403@gmail.com> <20060911082025.GD1898@elf.ucw.cz> <20060911195546.GB11901@elf.ucw.cz> <4505CCDA.8020501@gmail.com> <20060911210026.GG11901@elf.ucw.cz> <4505DDA6.8080603@gmail.com> <20060911225617.GB13474@elf.ucw.cz> <20060912001701.GC14234@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060912001701.GC14234@linux.intel.com> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1407 Lines: 32 On Mon, Sep 11, 2006 at 05:17:01PM -0700, Mark Gross wrote: > > cpufreq is broken at the cpufreq_driver interface for embedded > applications needing control over more than one control variable at a > time. > > That interface only supports setting target frequencies, and expanding it > to set target frequencies and voltages is not possible without something > like PowerOP. Adding the types of parameters to cpufreq would likely > make cpufreq a mess. I think we would be better off with something that > coexists with cpufreq, like the powerop patch from Eugeny. > > God help you if you try to use cpufreq on a complex non-PC platform with > multiple power and clock domains that need to be tweaked to squeeze out > competitive battery life. > > Because of the existing user base of cpufreq removing cpufreq will never > happen. No one supporting the PowerOP patch has never recommended > such a thing. However; holding back innovation because of an existing > solution that doesn't support a large class of users seems dumb. But you can't break the existing stuff, and it seems that some of these proposals are doing just that. :( thanks, greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/