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=-11.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 07549C433E2 for ; Tue, 1 Sep 2020 09:06:54 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ADC872071B for ; Tue, 1 Sep 2020 09:06:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="n4RyaB8c" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ADC872071B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=pZ1ZD0sliL6syFfluu7eLworvquRk1L2NoNnJZaFgrs=; b=n4RyaB8cOds7SHKiCkE/KbpTx Cdto4zQdI7iJ9Dt8Ty7cuoTbpDWUixPASNyMrIc1UTajBwDiJ7rpjN9dpwhfsz49ZJtTUQTlTPPQK IJ9blbK0XlXUirZxyzrwM3/RmzxeELcF/v2l//fHcTSCQES4xr5q+Q4cTNmGpCnlcREUFY0r+1S+r z5uCnUit+LysRKlkNH+niBTBBEe2VioP+ytJ7zzHSg+92RKK41kds/U9OZ/FlTUl4gLgAgNk4vYvb TZHdkaoXadmmcCLjQBkyiuNoFM7wjCHKLyAwE/I2+kjsKLuG1DJINU4wPZ8XyAK7osRoH1WpK01HX ozFknL8dw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kD2E4-0001Bw-JG; Tue, 01 Sep 2020 09:05:12 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kD2Ad-0008U0-C9 for linux-arm-kernel@lists.infradead.org; Tue, 01 Sep 2020 09:01:40 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9ADA730E; Tue, 1 Sep 2020 02:01:34 -0700 (PDT) Received: from bogus (unknown [10.57.5.92]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D6DB83F71F; Tue, 1 Sep 2020 02:01:31 -0700 (PDT) Date: Tue, 1 Sep 2020 10:01:25 +0100 From: Sudeep Holla To: Ulf Hansson Subject: Re: [PATCH] cpuidle: psci: Allow PM domain to be initialized even if no OSI mode Message-ID: <20200901090125.GA14397@bogus> References: <20200814123436.61851-1-ulf.hansson@linaro.org> <20200818123507.GD6873@bogus> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200901_050139_632348_E72B54C2 X-CRM114-Status: GOOD ( 41.32 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lorenzo Pieralisi , Vincent Guittot , Benjamin Gaignard , Linux PM , Stephen Boyd , Daniel Lezcano , "Rafael J . Wysocki" , Lina Iyer , Bjorn Andersson , Linux ARM , Lukasz Luba Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Aug 19, 2020 at 10:20:52AM +0200, Ulf Hansson wrote: > On Tue, 18 Aug 2020 at 14:35, Sudeep Holla wrote: > > > > On Fri, Aug 14, 2020 at 02:34:36PM +0200, Ulf Hansson wrote: > > > If the PSCI OSI mode isn't supported or fails to be enabled, the PM domain > > > topology with the genpd providers isn't initialized. This is perfectly fine > > > from cpuidle-psci point of view. > > > > > > > Indeed. > > > > > However, since the PM domain topology in the DTS files is a description of > > > the HW, no matter of whether the PSCI OSI mode is supported or not, other > > > consumers besides the CPUs may rely on it. > > > > > > > And why are they even registered as part of cpuidle-psci-domain ? > > If they have to be, can be decouple it completely from cpuidle then ? > > These devices can't be decoupled as they are a part of the CPU cluster > PM domain. > > This is for example the case RPMH (rsc) device for Qcom platforms, but > there are other platforms that need this too. > > > > > > Therefore, let's always allow the initialization of the PM domain topology > > > to succeed, independently of whether the PSCI OSI mode is supported. > > > Consequentially we need to track if we succeed to enable the OSI mode, as > > > to know when a domain idlestate can be selected. > > > > > > > I thought we had discussed this in past, why are we back to the same > > discussion ? I may need to read those again to get the context. > > That discussion was according to my understanding about whether we > should allow CPU devices to be managed by runtime PM and the CPU PM > domains, if OSI was *not* supported. > > We concluded that we didn't want to allow that, which makes sense - > and I am not changing that in $subject patch. > > > > > > Note that, CPU devices are still not being attached to the PM domain > > > topology, unless the PSCI OSI mode is supported. > > > > > > Signed-off-by: Ulf Hansson > > > --- > > > drivers/cpuidle/cpuidle-psci-domain.c | 49 +++++++++++++-------------- > > > 1 file changed, 24 insertions(+), 25 deletions(-) > > > > > > diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c > > > index b6e9649ab0da..55653c110e3a 100644 > > > --- a/drivers/cpuidle/cpuidle-psci-domain.c > > > +++ b/drivers/cpuidle/cpuidle-psci-domain.c > > > @@ -28,6 +28,7 @@ struct psci_pd_provider { > > > > > > static LIST_HEAD(psci_pd_providers); > > > static bool psci_pd_allow_domain_state; > > > +static bool psci_osi_mode_enabled; > > > > > > static int psci_pd_power_off(struct generic_pm_domain *pd) > > > { > > > @@ -37,7 +38,7 @@ static int psci_pd_power_off(struct generic_pm_domain *pd) > > > if (!state->data) > > > return 0; > > > > > > - if (!psci_pd_allow_domain_state) > > > + if (!psci_pd_allow_domain_state || !psci_osi_mode_enabled) > > > > I really don't like this check. Why do we have to keep checking > > psci_osi_mode_enabled every single time and that is the reason IIRC > > I was against this and just don't add the domains. > > You have a point about the check, it's not very nice - but from an > execution point of view, I don't think it's the end of the world. > > Note that, when not using OSI, then the ->power_off() callback will > not be invoked in the cpuidle path. > Then drop the check. I am confused as why we need that runtime check if we get the setup right. > Anyway, if you like, I can try to rework the code, so that the > ->power_off() callback doesn't get assigned, if we are not using OSI. +1 for sure. > Although, I am not sure the trouble is worth it, as I probably need to > try to enable OSI before initializing the genpd data structures. Then, > if failing with genpd initializations, I need to revert back to PC > mode. > Just to clarify, you can use psci_osi_mode_enabled anytime during initialisation and get the setup right so that we can drop unnecessary runtime check every single poweroff call. I prefer to remove that. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel