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=-11.4 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 7129BC43457 for ; Fri, 16 Oct 2020 13:09:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BD892071A for ; Fri, 16 Oct 2020 13:09:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="E9r8pmWq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406741AbgJPNJx (ORCPT ); Fri, 16 Oct 2020 09:09:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408200AbgJPNJO (ORCPT ); Fri, 16 Oct 2020 09:09:14 -0400 Received: from mail-wr1-x444.google.com (mail-wr1-x444.google.com [IPv6:2a00:1450:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A7DCC0613D6 for ; Fri, 16 Oct 2020 06:09:13 -0700 (PDT) Received: by mail-wr1-x444.google.com with SMTP id e17so2805945wru.12 for ; Fri, 16 Oct 2020 06:09:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=eyHBJddDTbNPFeEpW+RroYrsG4+cEx3Q/2uix0wzOfQ=; b=E9r8pmWqGNv7QdV+tX6/6JYGehMkG0K7T0kEJ6WtZgJWRJGjrtTAnbe+IP3139FQH1 pmStuVpaB0g1MaCmOFsN2UclDZMzpUN1tLt007fD0IBnDezvtqaxabzZiZZMzs0yVnSM FmkAiigUXgmK177YJvOq0/1sTmPbB5JGk7r2uS4VsZmrvD2ZEznJD1d+mBStQF9yEOtZ kVCFpsoXd8gBvmVXB8ePrHyT0A0uyg+Cs/FghA+LZslDdJYh+CrAyjIqh502bf1MzRKP vHgve0jdyaKaeSgyGmyy+KTwwCqmBVZ9QLb9yI737edsqY+8oe7a5k0jYY5peDSuBXRT AfVw== 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; bh=eyHBJddDTbNPFeEpW+RroYrsG4+cEx3Q/2uix0wzOfQ=; b=VcRBZBO0i2B3/Zt5mGTNrZl3jUDUMpMv/TUX6e7glRs37+dnGuEsHwgt+3z6m+VwYe EvpAEaMbai/0SrNmn5Mnp3GcqFP8GEKjYeKDXR5x9bb4aany61WR+TLWrhXHNPmFvmZg 4aSLy/IVOcDScCOfXP99Hok7WR6zq3lv8QNPmjGssQIYg4m/+W7XLu6m5M8bLG4zws2a nQLPpMlIGJ+vAtIri4GIxBo/1ImIEAqeL3qLkomcilzOKk+PXMkly66xLMeakpJ0/P8c QGH1cP9F4CZcARRMcAZH9WBAXR6Cx/INJB/+vM7poE5KoVeRVwvPoN/D9iUtPFcF1qqJ 6WLA== X-Gm-Message-State: AOAM533gJzme4/c3xEoW/7sSWyMyE69WQinVOnicJ+EYzVh7d7h2MKFu lEOtav/BNJMLCXakF8aM2vgxvQ== X-Google-Smtp-Source: ABdhPJyJx2ziKX8CMV9mtHGWssCPDzWgGWdhDq5rg06Ua4cfCHB0ZtCFKPT068dgSrnPDzX14r37mQ== X-Received: by 2002:a5d:5090:: with SMTP id a16mr3713627wrt.281.1602853749936; Fri, 16 Oct 2020 06:09:09 -0700 (PDT) Received: from google.com ([2a00:79e0:d:110:f693:9fff:fef4:a7ef]) by smtp.gmail.com with ESMTPSA id s1sm2694735wmh.22.2020.10.16.06.09.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 16 Oct 2020 06:09:09 -0700 (PDT) Date: Fri, 16 Oct 2020 14:09:05 +0100 From: Quentin Perret To: Daniel Lezcano Cc: "Rafael J. Wysocki" , Lukasz Luba , "Rafael J. Wysocki" , Linux Kernel Mailing List , Linux PM , "open list:DOCUMENTATION" , "devicetree@vger.kernel.org" , Rob Herring , Amit Kucheria , Jonathan Corbet , Dietmar Eggemann , Doug Anderson , Matthias Kaehlcke , "Nayak, Rajendra" Subject: Re: [PATCH v2 0/3] Clarify abstract scale usage for power values in Energy Model, EAS and IPA Message-ID: <20201016130905.GA2426638@google.com> References: <55d3fb0f-f7d8-63c5-2bdb-53eaa62380e0@linaro.org> <3e3dd42c-48ac-7267-45c5-ca88205611bd@arm.com> <00ceec64-3273-bb4a-6f38-22de8d877ab5@linaro.org> <20201016121844.GA2420691@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 16 Oct 2020 at 14:50:29 (+0200), Daniel Lezcano wrote: > On 16/10/2020 14:18, Quentin Perret wrote: > > On Friday 16 Oct 2020 at 13:48:33 (+0200), Daniel Lezcano wrote: > >> If the SCMI is returning abstract numbers, the thermal IPA governor will > >> use these numbers as a reference to mitigate the temperature at the > >> specified sustainable power which is expressed in mW in the DT. So it > >> does not work and we can not detect such conflict. > >> > >> That is why I'm advocating to keep mW for the energy model and make the > >> SCMI and DT power numbers incompatible. > > > > I think it's fair to say SCMI-provided number should only be compared to > > other SCMI-provided numbers, so +1 on that. But what I don't understand > > is why specifying the EM in mW helps with that? > > It is already specified in mW. I'm just saying to not add the > 'scale'/'abstract'/'bogoWatt' in the documentation. > > > Can we not let the providers specify the unit? > > Yes, it is possible but the provider must give the 'unit' and the energy > model must store this information along with the "power" numbers, so we > can compare apple with apple. > > Today, the energy model is using the mW unit only and the providers are > not telling the 'unit', so both are missing. > > Because both are missing, it does not make sense to talk about > 'abstract' values in the energy model documentation until the above is > fixed. Right, so that sounds like a reasonable way forward with this series. Lukasz would you be able to re-spin this with a first patch that allows the EM provider to specify a unit? And perhaps we could use Doug's idea for the sustained power DT binding and allow specifying a unit explicitly there too, so we're sure to compare apples with apples. Thanks, Quentin