Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760366Ab3CHEUo (ORCPT ); Thu, 7 Mar 2013 23:20:44 -0500 Received: from mail-oa0-f50.google.com ([209.85.219.50]:52963 "EHLO mail-oa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756010Ab3CHEUn (ORCPT ); Thu, 7 Mar 2013 23:20:43 -0500 MIME-Version: 1.0 In-Reply-To: References: <6cba8f153cfd4b0d3075a34a6dfe287bdec2eb06.1362676407.git.viresh.kumar@linaro.org> Date: Fri, 8 Mar 2013 12:20:42 +0800 Message-ID: Subject: Re: [PATCH V2] cpufreq: ARM big LITTLE: Add generic cpufreq driver and its DT glue From: Viresh Kumar To: Guennadi Liakhovetski Cc: rjw@sisk.pl, Steve.Bannister@arm.com, linux@arm.linux.org.uk, linux-pm@vger.kernel.org, Sudeep KarkadaNagesha , devicetree-discuss@lists.ozlabs.org, Liviu.Dudau@arm.com, linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, robin.randhawa@arm.com, linux-arm-kernel@lists.infradead.org, mark.hambleton@broadcom.com, linaro-kernel@lists.linaro.org, charles.garcia-tobin@arm.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1365 Lines: 32 On 8 March 2013 05:56, Guennadi Liakhovetski wrote: > I like generic drivers :) Me too :) > cpufreq-cpu0 is yet another such generic > (cpufreq) driver. Now, comparing the functionality of the two: Great!! > we see, that this driver "only" switches CPU clock frequencies. Whereas > the cpufreq-cpu0 driver also manipulates a regulator (if available) > directly. I understand, power-saving is also an important consideration > for big.LITTLE systems. So, I presume, you plan to implement voltage > switching in cpufreq notifiers? So the platform on which we are currently testing these is ARM TC2 Soc and this switching is done by the firmware instead. And so didn't went for regulator hookups initially.. Obviously in future regulator hookups would find some space in this driver but not required for now. > Now, my question is: is this (notifier) > actually the preferred method and the cpufreq-cpu0 driver is doing it > "wrongly?" What notifiers are you talking about? I believe using the regulator framework is the right way of doing this. And that would be part of this code later on. -- 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/