From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB2AAC76191 for ; Thu, 18 Jul 2019 13:36:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4D0320880 for ; Thu, 18 Jul 2019 13:36:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727687AbfGRNgk (ORCPT ); Thu, 18 Jul 2019 09:36:40 -0400 Received: from foss.arm.com ([217.140.110.172]:58504 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726715AbfGRNgk (ORCPT ); Thu, 18 Jul 2019 09:36:40 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0C67D344; Thu, 18 Jul 2019 06:36:39 -0700 (PDT) Received: from e121166-lin.cambridge.arm.com (unknown [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 754163F71F; Thu, 18 Jul 2019 06:36:36 -0700 (PDT) Date: Thu, 18 Jul 2019 14:36:30 +0100 From: Lorenzo Pieralisi To: Ulf Hansson Cc: Sudeep Holla , Mark Rutland , Linux ARM , "Rafael J . Wysocki" , Daniel Lezcano , "Raju P . L . S . S . S . N" , Amit Kucheria , Bjorn Andersson , Stephen Boyd , Niklas Cassel , Tony Lindgren , Kevin Hilman , Lina Iyer , Viresh Kumar , Vincent Guittot , Geert Uytterhoeven , Souvik Chakravarty , Linux PM , linux-arm-msm , Linux Kernel Mailing List Subject: Re: [PATCH 10/18] drivers: firmware: psci: Add hierarchical domain idle states converter Message-ID: <20190718133630.GB27222@e121166-lin.cambridge.arm.com> References: <20190513192300.653-1-ulf.hansson@linaro.org> <20190513192300.653-11-ulf.hansson@linaro.org> <20190709153138.GA22871@e121166-lin.cambridge.arm.com> <20190716145121.GA32490@e121166-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Thu, Jul 18, 2019 at 01:43:44PM +0200, Ulf Hansson wrote: [...] > > > Anyway, as a suggestion to address your concern, how about this: > > > > > > 1. Move some things out to a PSCI cpuidle driver. We need to decide > > > more exactly on what to move and find the right level for the > > > interfaces. > > > > I will do it and post patches asap. > > Okay, so I will wait for you to converting the cpuidle-arm driver into > a cpuidle-psci driver (and all the changes that comes with it) and > then base my re-base my series on top. > > Then, would you mind sharing (even in an early phase) a > branch/git-tree so I can start re-basing my series on top? Sure, I should be able to post at -rc1 and will publish a branch here [1]. > > > 2. Don't attach the CPU to the PM domain topology in case the PSCI PC > > > mode is used. I think this makes it easier, at least as a first step, > > > to understand when runtime PM needs to be used/enabled. > > > > In the PSCI CPUidle driver we can have two distinct struct > > cpuidle_state->enter functions for PC and OSI, no overhead > > for PC, runtime PM for OSI, decoupling done. > > Good idea! > > > > > We can choose one or the other depending on whether: > > > > OSI iff: > > - OSI is available > > - hierarchical idle states are present in DT > > > > otherwise PC. > > > > That's what this patch does but we will do it in a unified file. > > Sure, it makes sense. > > > > > > 3. Would it help if I volunteer to help you guys as a maintainer for > > > PSCI. At least for the part of the new code that becomes introduced? > > > > We will do as described above if that makes sense. > > Yep, I am okay with your suggestions, assuming I have understood them correctly. > > BTW, have you considered to host a git tree for PSCI so we can have > changes pre-integrated and tested in Stephen Rothwell's linux-next > tree? I will ask Stephen to pull when needed a branch in the tree below[1] [1] https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git/