From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leo Yan Subject: Re: [PATCH 1/2] cpufreq: hisilicon: add acpu driver Date: Mon, 2 Mar 2015 19:14:07 +0800 Message-ID: <20150302111406.GA18498@leoy-linaro> References: <1424956899-8891-1-git-send-email-leo.yan@linaro.org> <1424956899-8891-2-git-send-email-leo.yan@linaro.org> <20150302105025.GA8702@leoy-linaro> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pd0-f177.google.com ([209.85.192.177]:33486 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751258AbbCBLON (ORCPT ); Mon, 2 Mar 2015 06:14:13 -0500 Received: by pdjz10 with SMTP id z10so38943412pdj.0 for ; Mon, 02 Mar 2015 03:14:13 -0800 (PST) Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar Cc: "Rafael J . Wysocki" , "linux-pm@vger.kernel.org" , Linux Kernel Mailing List , "linux-arm-kernel@lists.infradead.org" , Dan Zhao , zhenwei.wang@hisilicon.com, mohaoju@hisilicon.com On Mon, Mar 02, 2015 at 04:34:34PM +0530, Viresh Kumar wrote: > On 2 March 2015 at 16:20, Leo Yan wrote: > > i'm glad to use more general method, let me give more input so that we > > can see if can figure out a better way. ;) > > And I am glad to hear that :) > > > 1. From hardware design, during the initialization phase, it will > > bind every opps with its corresponding voltage, and pass these related > > info to power controller. So later, in kernel the cpufreq driver don't > > need manually change the voltage, it will only change the cpu clock > > frequency and power controller will automatically handle voltage > > related operations. This is similar with TC's SPC implementation. > > > > So looks likely the cpufreq-dt driver's voltage related ops are > > redundant for this case. > > Its okay, they wouldn't harm. You don't have to specify any regulator > in CPUs DT node and the code will not try any fancy stuff :) If so, it's make sense to directly use cpufreq-dt driver; i will try it firstly. Appreciate for suggestion :) Thanks, Leo Yan