Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DF955C05027 for ; Wed, 8 Feb 2023 15:20:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229837AbjBHPTv (ORCPT ); Wed, 8 Feb 2023 10:19:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231451AbjBHPTp (ORCPT ); Wed, 8 Feb 2023 10:19:45 -0500 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30DA14ABD4; Wed, 8 Feb 2023 07:19:45 -0800 (PST) Received: by mail-pj1-x102d.google.com with SMTP id j1so12817227pjd.0; Wed, 08 Feb 2023 07:19:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=xAQNOEz10pxYOiqzmdo+aFdBHrodKxaja7D61VZvZKE=; b=oqqNObI/+zH/weckd22QIJi/PdQzGXPqbnwY4J9NNpBNndsiw16oTiWxgpwIdTYWqd Ag/szpXZVx9hMihQ/QMqMdTU1Tu+0o8s6va66pQiqFDy3Y1XOCcvXHSsIuj77HfhnKMR mTy1+IQdRMdorJSmG2kmbPHhhUU30VPDBDEjxWdpenk5vgFkpA2VrsnklAzByPenOSvq 2RDwIjR4Skx7EmtrmEbW7eR1hLq41tuAGdvkgqwqi3FhY7Vhen311EE0mR8xvsdYpHjv /0mt7GffAJVmoktocxQ1MXhXBinUtNpokjEBnyGrEgutXCC+FgKSgKDG2HJyj593LOox PbUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=xAQNOEz10pxYOiqzmdo+aFdBHrodKxaja7D61VZvZKE=; b=4UNGlk2EDV3UBu7yFlPijf54+TsiFhAbonjyWPyqtmLr9aON6cVebguWMvJkDcGuhZ 1GIAq6uQ/Ls4FdqtF0pzkeJczMbPD7wOSqcZpo8/jxpX7Rf87uZwIe9+GyRywaJFlE8d 9NoksgJzOLNRQFDfz1DPCaMwCnYgjQgpHP5teIVmfyvlmJ2rLw4scUvLeviXwQhoC/sc 3EDdk30WqavMi2QeMcEi8YceNBSdbE0B78AanwCoj3ABGCLYaGSTuuz0eIYuerlN2sap rOLFbCCJV7ooQ8g9k52FzwzvnblVVohHgYWSnsVswybOsgxWafUKE5ZcLSG+c0KeM6EP NvcQ== X-Gm-Message-State: AO0yUKXFOU92Tbd7/PnktsYGgFrnkhv0Of2hdJjIFcgRUvSAFzlO+C0y wKfZ+1EXxKPb1KPB+eAEeA0gis4VMOxjGg== X-Google-Smtp-Source: AK7set9V9PKCVFfuxJLJob6eUGmN7YBPAEC6D+gaORlW+/r0IjinF8MZNXvfykcPKXrdgnmXcaU5OA== X-Received: by 2002:a05:6a20:6901:b0:b8:8a94:5bf with SMTP id q1-20020a056a20690100b000b88a9405bfmr8472613pzj.21.1675869584507; Wed, 08 Feb 2023 07:19:44 -0800 (PST) Received: from kazuki-mac ([2400:4051:ea3:5910::19a]) by smtp.gmail.com with ESMTPSA id io20-20020a17090312d400b0019934030f46sm3317995plb.132.2023.02.08.07.19.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Feb 2023 07:19:44 -0800 (PST) From: Kazuki X-Google-Original-From: Kazuki Date: Thu, 9 Feb 2023 00:19:39 +0900 To: Sudeep Holla Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, "Rafael J. Wysocki" , Daniel Lezcano , Lorenzo Pieralisi , Hector Martin , Sven Peter , Len Brown , Pavel Machek Subject: Re: s2idle breaks on machines without cpuidle support Message-ID: <20230208151939.meya6c5gayspvmtr@kazuki-mac> References: <20230204152747.drte4uitljzngdt6@kazuki-mac> <20230206101239.dret3fv65cnzpken@bogus> <20230207194818.exskn3dhyzqwr32v@kazuki-mac> <20230208103511.w7jzxw6spy6humdn@bogus> <20230208112031.sdfuluajjerf4wwp@kazuki-mac> <20230208141658.kede5ylqk4zqvrnj@bogus> <20230208144327.3ftjxnquwhsdykfc@kazuki-mac> <20230208150306.ve2pnt3pvlmf5wbu@bogus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230208150306.ve2pnt3pvlmf5wbu@bogus> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 08, 2023 at 03:03:06PM +0000, Sudeep Holla wrote: > On Wed, Feb 08, 2023 at 11:43:27PM +0900, Kazuki wrote: > > On Wed, Feb 08, 2023 at 02:16:58PM +0000, Sudeep Holla wrote: > > [...] > > > > I was about ask you earlier as why can't you implement just system > > > suspend in PSCI where the last cpu just calls WFI if you are interested > > > in system sleep state. Or you can implement CPU_SUSPEND with an additional > > > retention state which enters PSCI implementation just to make sure there is > > > an active cpuidle driver and the s2idle state machinery works as expected. > > > > The machine I have (Macbook with Apple M1) doesn't have PSCI. > > Well, if we are allowing to boot on such a system, then we must allow > adding a platform specific idle driver. It may be useful once we info > to add deeper than WFI states. Hmmm, I thought for arm64, non-PSCI idle drivers were prohibited? Or am I mistaken here? > > > I guess we should ensure that systems without a cpuidle driver > > will not suspend maybe around here then. > > > > Are we ? I thought were making changes to enable it. Or are you saying > we allow to enter into such a state and render the system unusable, if > so we need to fix it. Both as I mentioned in my first email. Apologies if it turned out to be confusing. Thanks, Kazuki