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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 7829FC5517A for ; Fri, 30 Oct 2020 09:52:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1062420825 for ; Fri, 30 Oct 2020 09:52:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="aJO1l8mh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726061AbgJ3Jwx (ORCPT ); Fri, 30 Oct 2020 05:52:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726112AbgJ3Jww (ORCPT ); Fri, 30 Oct 2020 05:52:52 -0400 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C9B8C0613D2 for ; Fri, 30 Oct 2020 02:52:52 -0700 (PDT) Received: by mail-pf1-x443.google.com with SMTP id 13so4804121pfy.4 for ; Fri, 30 Oct 2020 02:52:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=LouD1D0I3seOHVdhKfAMAsty+PIB9yldQNSOZd2AunQ=; b=aJO1l8mh4uw/GnTl5HY0NA+dwk++sWXQuGfLTVtl533+jm1Ua8w+Wey6I5HA7kFbT7 /OrX0mM9SkI3hgIomS6aGj1VoU84VFIs/KngRRZZlv0eqFfA7QHc/dPusglaVUaZEHeS bCc9UMq+1p3c5eBbePMJ1pnm9gmaKjIDe4AC9KLBvDw5vX1+/4iEjastJbhBYdAuq8NU d07nCQ+GQrNbl7sOdhngJ4LJvFcudsJLAECxVwtud5DIg1uzO4jtHeIZh9B9LwUghSZU FLeKjsbeoTK+tXDKFmhuXDgzbY/mAj5g/zqtQEJDat2mO1fqz9eBhdPk7zGyQs1YRdhL 4Xwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=LouD1D0I3seOHVdhKfAMAsty+PIB9yldQNSOZd2AunQ=; b=bDpDyBQ1CkuTaX23VJWPZtRp7AJfCt3sWFUCmohzTvH9ojONd/La/QXy75mHQ7uazZ UI8wkszSWD5JTZ4yigkZmulOdEp8lqTQXFBnURYEtEVwpjrN5V+OAFz9/HMlzXfrvX1C jX44XuwEd1fJpRdz/YmA0Fj8sTGOzzZiBOElTjCXOnYAvOWz7SlIa1o9JmrRu07sf1Bt Oq/8ZRajEiwaugQd6dRCRHlMUZFtpTzKMwZtoo0ORV3kLLNo4XTkXJFkBRFKT/sW11TP a+FBlnZlH4Ip75xrKuM8n/AyGqDHWpQdtTHbItQ/GqlDEZeQreasfhhpgiTZkshgxPnt rETg== X-Gm-Message-State: AOAM530/ZiNVBbFzpLBlwO0kltrLOzKtXvCfDA71970fHAuFpV2UO1uu 5JAbTC+pn6YbUBzonD/onZ/FrA== X-Google-Smtp-Source: ABdhPJwg8INqFRnK0JxdmUemZAqhRWMZQOBYvn0HloepQQgK4PC8ob7yeNm/niQ1Z7nrQd17NwIeSg== X-Received: by 2002:a17:90a:2ec1:: with SMTP id h1mr1894047pjs.51.1604051571650; Fri, 30 Oct 2020 02:52:51 -0700 (PDT) Received: from localhost ([122.181.54.133]) by smtp.gmail.com with ESMTPSA id z10sm5422539pff.218.2020.10.30.02.52.50 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 30 Oct 2020 02:52:50 -0700 (PDT) Date: Fri, 30 Oct 2020 15:22:48 +0530 From: Viresh Kumar To: Lukasz Luba Cc: vincent.guittot@linaro.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, vireshk@kernel.org, robh+dt@kernel.org, sboyd@kernel.org, nm@ti.com, rafael@kernel.org, sudeep.holla@arm.com, daniel.lezcano@linaro.org, Dietmar.Eggemann@arm.com Subject: Re: [PATCH 0/4] Add sustainable OPP concept Message-ID: <20201030095248.abej6h5wphud2ihb@vireshk-i7> References: <20201028140847.1018-1-lukasz.luba@arm.com> <20201029074057.6ugmwyzna52x3oli@vireshk-i7> <20201029075356.rruej6jlerhfa4oy@vireshk-i7> <228fa1b3-bbd3-6941-fd4b-06581016d839@arm.com> <20201030082937.xgjmko2ohwhkt6f5@vireshk-i7> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716-391-311a52 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 30-10-20, 09:19, Lukasz Luba wrote: > How about dropping the DT binding, but just adding this new field into > dev_pm_opp? There will be no DT parsing code, just the get/set > functions, which will be used in SCMI patch 4/4 and in IPA? > That would not require to change any DT bindings. > I see. Just for your information SCMI supports 'Sustained Performance' > expressed in kHz. Even that doesn't sound great (but then I don't have any background of why that was added there). The problem is not about how do we get this data into the kernel (from DT or firmware), but why is it even required. I really feel that software can find the sustainable OPP by itself (which can keep changing). About moving it into the OPP core, I am open to getting something added there if it is really useful and if the OPP core is the best suited place to keep such data. Though I am not sure of that for this field right now. Is it ever going to be used by anyone else apart from IPA ? If not, what about adding a helper in IPA to set sustainable-freq for a device ? So only SCMI based platforms will be able to use this stuff ? That's very limited, isn't it ? I think we should still try to make it better for everyone by making the software smarter. It has so much data, the OPPs, the power it will consume (based on microvolt property?), the heat we produce from that (from thermal framework), etc. Perhaps building this information continuously at runtime based on when and how we hit the trip points ? So we know which is the right frequency where we can refrain from hitting the trip points. But may be I am asking too much :( -- viresh