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=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 8978AC31E44 for ; Mon, 17 Jun 2019 04:25:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DB5D2182B for ; Mon, 17 Jun 2019 04:25:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="kQVJ9Osh"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="G3dth9pB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726029AbfFQEZI (ORCPT ); Mon, 17 Jun 2019 00:25:08 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:53192 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725989AbfFQEZI (ORCPT ); Mon, 17 Jun 2019 00:25:08 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 7616160735; Mon, 17 Jun 2019 04:25:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1560745506; bh=5HZNkcP2zjhga4bMIOWXDoG0/nXxrlZAjw0ECMvGYK8=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=kQVJ9Osh3eNJuFAi59AX3O0oOU/n2R1TLKeFsvszpLQZT49bJMj86kNYSvp7k6e+J 5RPT6GNe3kh9dMasg/eJlxZnFiHsAI9fTu/bzk9oq1kQaQ2tikD3pkVWsd3LaXag9a hTlnLJOVQjC7nbGJBX0MOWdSTiKTWm5+JadThbZ8= Received: from [10.131.117.43] (blr-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.18.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: rnayak@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id D977860735; Mon, 17 Jun 2019 04:25:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1560745505; bh=5HZNkcP2zjhga4bMIOWXDoG0/nXxrlZAjw0ECMvGYK8=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=G3dth9pBIldbPRyid5w1N1yL/bTUx8NuG1TbpDv3Y2g4jKBqOHr9ICd/Ucdl2ISGf zpAQa/+hK2ijNE1odvZQHhIT8OEW/U9CuNLp5iSChIt6UAp8Sz4aHfprpBQPeE1gcH FgAekDIFTXanc5VeqZtXhzbOybouHaMjoY15PVN8= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D977860735 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=rnayak@codeaurora.org Subject: Re: [RFC v2 01/11] OPP: Don't overwrite rounded clk rate To: Viresh Kumar Cc: swboyd@chromium.org, vincent.guittot@linaro.org, mturquette@baylibre.com, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-pm@vger.kernel.org, linux-serial@vger.kernel.org, linux-spi@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-scsi@vger.kernel.org, ulf.hansson@linaro.org, dianders@chromium.org, rafael@kernel.org References: <20190320094918.20234-1-rnayak@codeaurora.org> <20190320094918.20234-2-rnayak@codeaurora.org> <20190611105432.x3nzqiib35t6mvyg@vireshk-i7> <20190612082506.m735bsk7bjijf2yg@vireshk-i7> <20190613095419.lfjeko7nmxtix2n4@vireshk-i7> <20190614052732.4w6vvwwich2h4cgu@vireshk-i7> <20190617035058.veo7uwqjrpa6kykt@vireshk-i7> <20190617041721.5xdr3kl4xxe6gy4m@vireshk-i7> From: Rajendra Nayak Message-ID: Date: Mon, 17 Jun 2019 09:55:00 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.1 MIME-Version: 1.0 In-Reply-To: <20190617041721.5xdr3kl4xxe6gy4m@vireshk-i7> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 6/17/2019 9:47 AM, Viresh Kumar wrote: > On 17-06-19, 09:37, Rajendra Nayak wrote: >> >> >> On 6/17/2019 9:20 AM, Viresh Kumar wrote: >>> On 14-06-19, 10:57, Viresh Kumar wrote: >>>> Hmm, so this patch won't break anything and I am inclined to apply it again :) >>>> >>>> Does anyone see any other issues with it, which I might be missing ? >>> >>> I have updated the commit log a bit more to clarify on things, please let me >>> know if it looks okay. >>> >>> opp: Don't overwrite rounded clk rate >>> The OPP table normally contains 'fmax' values corresponding to the >>> voltage or performance levels of each OPP, but we don't necessarily want >>> all the devices to run at fmax all the time. Running at fmax makes sense >>> for devices like CPU/GPU, which have a finite amount of work to do and >>> since a specific amount of energy is consumed at an OPP, its better to >>> run at the highest possible frequency for that voltage value. >>> On the other hand, we have IO devices which need to run at specific >>> frequencies only for their proper functioning, instead of maximum >>> possible frequency. >>> The OPP core currently roundup to the next possible OPP for a frequency >>> and select the fmax value. To support the IO devices by the OPP core, >>> lets do the roundup to fetch the voltage or performance state values, >>> but not use the OPP frequency value. Rather use the value returned by >>> clk_round_rate(). >>> The current user, cpufreq, of dev_pm_opp_set_rate() already does the >>> rounding to the next OPP before calling this routine and it won't >>> have any side affects because of this change. >> >> Looks good to me. Should this also be documented someplace that dev_pm_opp_set_rate() >> would not be able to distinguish between its users trying to scale CPU/GPU's vs IO >> devices, so its the callers responsibility to round it accordingly before calling the >> API? > > diff --git a/drivers/opp/core.c b/drivers/opp/core.c > index 0fbc77f05048..bae94bfa1e96 100644 > --- a/drivers/opp/core.c > +++ b/drivers/opp/core.c > @@ -751,8 +751,11 @@ static int _set_required_opps(struct device *dev, > * @dev: device for which we do this operation > * @target_freq: frequency to achieve > * > - * This configures the power-supplies and clock source to the levels specified > - * by the OPP corresponding to the target_freq. > + * This configures the power-supplies to the levels specified by the OPP > + * corresponding to the target_freq, and programs the clock to a value <= > + * target_freq, as rounded by clk_round_rate(). Device wanting to run at fmax > + * provided by the opp, should have already rounded to the target OPP's > + * frequency. > */ Perfect, thanks. -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation