From mboxrd@z Thu Jan 1 00:00:00 1970 From: Quentin Perret Subject: Re: [PATCH 3/3] thermal: cpu_cooling: Migrate to using the EM framework Date: Wed, 10 Apr 2019 09:57:04 +0100 Message-ID: <20190410085702.nll6spd565oio3ds@queper01-lin> References: <20190328101352.25657-1-quentin.perret@arm.com> <20190328101352.25657-4-quentin.perret@arm.com> <20190410054449.zwmemg7vza557gue@vireshk-i7> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190410054449.zwmemg7vza557gue@vireshk-i7> Sender: linux-kernel-owner@vger.kernel.org To: Viresh Kumar Cc: edubezval@gmail.com, rui.zhang@intel.com, javi.merino@kernel.org, amit.kachhap@gmail.com, rjw@rjwysocki.net, will.deacon@arm.com, catalin.marinas@arm.com, daniel.lezcano@linaro.org, dietmar.eggemann@arm.com, ionela.voinescu@arm.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-pm@vger.kernel.org On Wednesday 10 Apr 2019 at 11:14:49 (+0530), Viresh Kumar wrote: > On 28-03-19, 10:13, Quentin Perret wrote: > > +static unsigned int get_state_freq(struct cpufreq_cooling_device *cpufreq_cdev, > > + unsigned long state) > > +{ > > + struct cpufreq_policy *policy; > > + unsigned long idx; > > + > > + /* Use the Energy Model table if available */ > > + if (cpufreq_cdev->em) { > > + idx = cpufreq_cdev->max_level - state; > > + return cpufreq_cdev->em->table[idx].frequency; > > + } > > + > > + /* Otherwise, fallback on the CPUFreq table */ > > + policy = cpufreq_cdev->policy; > > + if (policy->freq_table_sorted == CPUFREQ_TABLE_SORTED_ASCENDING) > > It is not guaranteed that the frequency table is sorted in any order, isn't it ? Hmm, indeed... I thought cpufreq_table_validate_and_sort() was actively sorting the table but it seems I was wrong. But I _think_ in practice the freq table actually happens to be sorted for the upstream cpufreq drivers with the CPUFREQ_IS_COOLING_DEV flag set. Most of them use dev_pm_opp_init_cpufreq_table() which guarantees the table is sorted and qoriq-cpufreq explicitly sorts the table. But I'm not sure about qcom-cpufreq-hw ... So, if the above is true, perhaps I could simply add a check to mandate that policy->freq_table_sorted != CPUFREQ_TABLE_SORTED_UNSORTED for cpu_cooling ? That shouldn't harm the existing users. Do you happen to know a board where the table is unsorted ? Is it a common use-case ? If yes, then I'll probably need to drop the dependency on cpufreq's freq_table and use something else to convert indexes into frequencies (PM_OPP ?). Unless we can force-sort the table in the cpufreq core, but that might require lots of changes to lots of drivers too. > > > + idx = cpufreq_cdev->max_level - state; > > + else > > + idx = state; > > -- > viresh Thanks, Quentin 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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_NEOMUTT autolearn=unavailable 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 26CFAC10F11 for ; Wed, 10 Apr 2019 08:57:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF601217D9 for ; Wed, 10 Apr 2019 08:57:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727602AbfDJI5J (ORCPT ); Wed, 10 Apr 2019 04:57:09 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:50286 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727057AbfDJI5J (ORCPT ); Wed, 10 Apr 2019 04:57:09 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 55BC5374; Wed, 10 Apr 2019 01:57:08 -0700 (PDT) Received: from queper01-lin (queper01-lin.cambridge.arm.com [10.1.195.48]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id ED1D73F59C; Wed, 10 Apr 2019 01:57:05 -0700 (PDT) Date: Wed, 10 Apr 2019 09:57:04 +0100 From: Quentin Perret To: Viresh Kumar Cc: edubezval@gmail.com, rui.zhang@intel.com, javi.merino@kernel.org, amit.kachhap@gmail.com, rjw@rjwysocki.net, will.deacon@arm.com, catalin.marinas@arm.com, daniel.lezcano@linaro.org, dietmar.eggemann@arm.com, ionela.voinescu@arm.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 3/3] thermal: cpu_cooling: Migrate to using the EM framework Message-ID: <20190410085702.nll6spd565oio3ds@queper01-lin> References: <20190328101352.25657-1-quentin.perret@arm.com> <20190328101352.25657-4-quentin.perret@arm.com> <20190410054449.zwmemg7vza557gue@vireshk-i7> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: <20190410054449.zwmemg7vza557gue@vireshk-i7> User-Agent: NeoMutt/20171215 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Message-ID: <20190410085704.FqjkTHwlubt_RWiSgh0h7-S0S5w5CMh-iXZsW6NIOVA@z> On Wednesday 10 Apr 2019 at 11:14:49 (+0530), Viresh Kumar wrote: > On 28-03-19, 10:13, Quentin Perret wrote: > > +static unsigned int get_state_freq(struct cpufreq_cooling_device *cpufreq_cdev, > > + unsigned long state) > > +{ > > + struct cpufreq_policy *policy; > > + unsigned long idx; > > + > > + /* Use the Energy Model table if available */ > > + if (cpufreq_cdev->em) { > > + idx = cpufreq_cdev->max_level - state; > > + return cpufreq_cdev->em->table[idx].frequency; > > + } > > + > > + /* Otherwise, fallback on the CPUFreq table */ > > + policy = cpufreq_cdev->policy; > > + if (policy->freq_table_sorted == CPUFREQ_TABLE_SORTED_ASCENDING) > > It is not guaranteed that the frequency table is sorted in any order, isn't it ? Hmm, indeed... I thought cpufreq_table_validate_and_sort() was actively sorting the table but it seems I was wrong. But I _think_ in practice the freq table actually happens to be sorted for the upstream cpufreq drivers with the CPUFREQ_IS_COOLING_DEV flag set. Most of them use dev_pm_opp_init_cpufreq_table() which guarantees the table is sorted and qoriq-cpufreq explicitly sorts the table. But I'm not sure about qcom-cpufreq-hw ... So, if the above is true, perhaps I could simply add a check to mandate that policy->freq_table_sorted != CPUFREQ_TABLE_SORTED_UNSORTED for cpu_cooling ? That shouldn't harm the existing users. Do you happen to know a board where the table is unsorted ? Is it a common use-case ? If yes, then I'll probably need to drop the dependency on cpufreq's freq_table and use something else to convert indexes into frequencies (PM_OPP ?). Unless we can force-sort the table in the cpufreq core, but that might require lots of changes to lots of drivers too. > > > + idx = cpufreq_cdev->max_level - state; > > + else > > + idx = state; > > -- > viresh Thanks, Quentin