From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751944Ab3CBC62 (ORCPT ); Fri, 1 Mar 2013 21:58:28 -0500 Received: from hqemgate03.nvidia.com ([216.228.121.140]:12733 "EHLO hqemgate03.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751367Ab3CBC61 (ORCPT ); Fri, 1 Mar 2013 21:58:27 -0500 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Fri, 01 Mar 2013 18:58:21 -0800 Message-ID: <1362193098.2407.27.camel@bilhuang-vm1> Subject: Re: [PATCH 2/5] clk: notifier handler for dynamic voltage scaling From: Bill Huang To: Stephen Warren CC: Mike Turquette , "linaro-dev@lists.linaro.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "patches@linaro.org" Date: Fri, 1 Mar 2013 18:58:18 -0800 In-Reply-To: <5131143D.2060904@wwwdotorg.org> References: <1362026969-11457-1-git-send-email-mturquette@linaro.org> <1362026969-11457-3-git-send-email-mturquette@linaro.org> <1362130891.19498.12.camel@bilhuang-vm1> <5131143D.2060904@wwwdotorg.org> X-Mailer: Evolution 3.2.3-0ubuntu6 MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-9" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2013-03-02 at 04:49 +0800, Stephen Warren wrote: > On 03/01/2013 02:41 AM, Bill Huang wrote: > > On Thu, 2013-02-28 at 12:49 +0800, Mike Turquette wrote: > >> There are three prerequisites to using this feature: > >> > >> 1) the affected clocks must be using the common clk framework > >> 2) voltage must be scaled using the regulator framework > >> 3) clock frequency and regulator voltage values must be paired via the > >> OPP library > > > > Just a note, Tegra Core won't meet prerequisite #3 since each regulator > > voltage values is associated with clocks driving those many sub-HW > > blocks in it. > > Perhaps that "just" means extending the dvfs.c code here to iterate over > each clock consumer (rather than each clock provider), and having each > set a minimum voltage (rather than a specific voltage), and having the > regulator core apply the maximum of those minimum constraints? > > Or something like that anyway. Thanks, I'll think about this or maybe study a bit, it sounds like we can leverage existing api in regulator framework (which I don't know) to do what you've proposed, please clarify if I misunderstand. > -- > 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/ From mboxrd@z Thu Jan 1 00:00:00 1970 From: bilhuang@nvidia.com (Bill Huang) Date: Fri, 1 Mar 2013 18:58:18 -0800 Subject: [PATCH 2/5] clk: notifier handler for dynamic voltage scaling In-Reply-To: <5131143D.2060904@wwwdotorg.org> References: <1362026969-11457-1-git-send-email-mturquette@linaro.org> <1362026969-11457-3-git-send-email-mturquette@linaro.org> <1362130891.19498.12.camel@bilhuang-vm1> <5131143D.2060904@wwwdotorg.org> Message-ID: <1362193098.2407.27.camel@bilhuang-vm1> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, 2013-03-02 at 04:49 +0800, Stephen Warren wrote: > On 03/01/2013 02:41 AM, Bill Huang wrote: > > On Thu, 2013-02-28 at 12:49 +0800, Mike Turquette wrote: > >> There are three prerequisites to using this feature: > >> > >> 1) the affected clocks must be using the common clk framework > >> 2) voltage must be scaled using the regulator framework > >> 3) clock frequency and regulator voltage values must be paired via the > >> OPP library > > > > Just a note, Tegra Core won't meet prerequisite #3 since each regulator > > voltage values is associated with clocks driving those many sub-HW > > blocks in it. > > Perhaps that "just" means extending the dvfs.c code here to iterate over > each clock consumer (rather than each clock provider), and having each > set a minimum voltage (rather than a specific voltage), and having the > regulator core apply the maximum of those minimum constraints? > > Or something like that anyway. Thanks, I'll think about this or maybe study a bit, it sounds like we can leverage existing api in regulator framework (which I don't know) to do what you've proposed, please clarify if I misunderstand. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/