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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 4876BC169C4 for ; Fri, 8 Feb 2019 10:52:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 17F4C21919 for ; Fri, 8 Feb 2019 10:52:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549623173; bh=klCbsfpMHNFcsyMTTbCCCssHSbItEI00WZA7nu9V+OU=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=CcgOhyLeLeHLD0UwNHYvw68tsgZE8422h2MiAz3Dr89PRoSL1ZZUn6VfbpWURUv9c 9EXpaI1ahWgLRdJ65wDY9QzzzJVfV+DnfHoZbUIq5LNd2fB3Y5mUf0HHf2X6nl/Duu ybexv0yI0w2/Lg9lTKT9FqXoPeDGx8gnYGqFK/wI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727660AbfBHKwv (ORCPT ); Fri, 8 Feb 2019 05:52:51 -0500 Received: from mail-ot1-f67.google.com ([209.85.210.67]:43779 "EHLO mail-ot1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726068AbfBHKwu (ORCPT ); Fri, 8 Feb 2019 05:52:50 -0500 Received: by mail-ot1-f67.google.com with SMTP id a11so5069728otr.10; Fri, 08 Feb 2019 02:52:50 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=gaqXY24CoPBcisgxoA2Xzo8Hq8vVjMfrseZDD3ry7d4=; b=jwaxjSxZzKahSheVo+vuS5bhefUAoMRmNgd7/1bFIM2m7d1e+Zz9V9GNmPpFne7vVY fzNoXRK8yjv6LTcvlkwcciWUmf7qt0MHg4kMsQYJOBavUtJDNJNsgQpDZgMfuSuztM3U 9ZB6HKsiYVN5Dp49n8AXDxtXOVArEz0TiAAhwXDDmBEUtngqYzFA3peysXh5+dovcQz4 zxo7bN39kuh1UDaXh8yYSrb0cgbqEEmRs+tqAC47HKuUxkelSwyNjIf2FkOlfTbmrWZO 7SapN7lkMTPyK/5joyzJ083DEDT+md2wIfJyBvq7HhKUgqFL1rj4YURINYyjhXaNfboB 5n8w== X-Gm-Message-State: AHQUAuZ4JH3Cf3OsTeSe9RD6VuuCi+T0jHqhzuoNLbXCRWjrMO6QqbGl WlbbZ7SdgMGqR5Dv77E29vWi/Y9c4TT1x32e8yw= X-Google-Smtp-Source: AHgI3IZhIpjUh7Dw0Nx+aum8zHYQBye3aUdVSQEiS2y2A5OI+7zhVpY4xiuj/I9qPMSmMhRhuwz2K16F/jpL8j7+Ctw= X-Received: by 2002:a9d:5f06:: with SMTP id f6mr12680524oti.258.1549623169842; Fri, 08 Feb 2019 02:52:49 -0800 (PST) MIME-Version: 1.0 References: <20190207122227.19873-1-m.szyprowski@samsung.com> <20190208064957.zhyue42kpgaoslwm@vireshk-i7> <20190208103133.ysvaroyniuc3k4i5@vireshk-i7> In-Reply-To: From: "Rafael J. Wysocki" Date: Fri, 8 Feb 2019 11:52:38 +0100 Message-ID: Subject: Re: [PATCH 0/2] cpufreq/opp: rework regulator initialization To: Viresh Kumar Cc: "Rafael J. Wysocki" , Marek Szyprowski , Linux Kernel Mailing List , Linux PM , Linux Samsung SoC , "Rafael J . Wysocki" , Nishanth Menon , Stephen Boyd , Bartlomiej Zolnierkiewicz , Dave Gerlach , Wolfram Sang Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 8, 2019 at 11:42 AM Rafael J. Wysocki wrote: > > On Fri, Feb 8, 2019 at 11:31 AM Viresh Kumar wrote: > > > > On 08-02-19, 11:22, Rafael J. Wysocki wrote: > > > There are cpufreq driver suspend and resume callbacks, maybe use them? > > > > > > The driver could do the I2C transactions in its suspend/resume > > > callbacks and do nothing in online/offline if those are part of > > > system-wide suspend/resume. > > > > These are per-policy things that we need to do, not sure if driver > > suspend/resume is a good place for that. It is more for a case where > > CPU 0-3 are in one policy and 4-7 in another. Now 1-7 are > > hot-unplugged during system suspend and hotplugged later on. This is > > more like complete removal/addition of devices instead of > > suspend/resume. > > No, it isn't. We don't remove devices on offline. We migrate stuff > away from them and (opportunistically) power them down. > > If this is system suspend, the driver kind of knows that offline will > take place, so it can prepare for it. Likewise, when online takes > place during system-wide resume, it generally is known that this is > system-wide resume (there is a flag to indicate that in CPU hotplug), > it can be "smart" and avoid accessing suspended devices. Deferring > the frequency set up until the driver resume time should do the trick > I suppose. BTW, do transitions to idle states involve I2C transactions on the systems in question?