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=-2.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_MUTT 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 7C218C2BCA1 for ; Fri, 7 Jun 2019 15:31:24 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 536972089E for ; Fri, 7 Jun 2019 15:31:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="nMU/0eN9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 536972089E 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+infradead-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=bombadil.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=kG25Rry59kXkhpsSvmgjcgBaQna/q9rYCJRxrn0NMP0=; b=nMU/0eN96pNSMj Ukhf0ZMJT7QOA7HUNpDWeujSA4ZEFOq5oAwvegBPk2dKEUwtw2l6s00i6xnGNOp7eshvZe9oiebsL 4/5Aio4F0nEdgZAP5/KuW2rYxll+pll/v3ChnJ4FmqOEjYBcq8eqo4CrKfaHumqZRPqaEsXIN1NSY ZMx2e/rxaOlS8YzRe//ZnlLE6az5rImIcn3ukCIrDJk9hVSGpDbX1n1Z2Tsj59U6nzcP1pUWRflMZ 5F6qebJdtYgiDO4espiY0klLQqWJ+reitv6pVCusAyzyiI2bfNn2hFMg+ijOYVIsYUjXWpO5Vdosk YWSYWqaa/oKMteyKF44Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hZGpu-0000lz-Sy; Fri, 07 Jun 2019 15:31:22 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hZGpr-0000kl-P6 for linux-arm-kernel@lists.infradead.org; Fri, 07 Jun 2019 15:31:21 +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 069B2499; Fri, 7 Jun 2019 08:31:19 -0700 (PDT) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 55FE43F718; Fri, 7 Jun 2019 08:31:16 -0700 (PDT) Date: Fri, 7 Jun 2019 16:31:14 +0100 From: Sudeep Holla To: Ulf Hansson Subject: Re: [PATCH 15/18] drivers: firmware: psci: Support CPU hotplug for the hierarchical model Message-ID: <20190607153114.GI15577@e107155-lin> References: <20190513192300.653-1-ulf.hansson@linaro.org> <20190513192300.653-16-ulf.hansson@linaro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190513192300.653-16-ulf.hansson@linaro.org> 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-20190607_083119_856615_F124EF68 X-CRM114-Status: GOOD ( 12.14 ) 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: Mark Rutland , Lorenzo Pieralisi , Geert Uytterhoeven , Kevin Hilman , Stephen Boyd , Viresh Kumar , linux-pm@vger.kernel.org, Daniel Lezcano , "Rafael J . Wysocki" , linux-kernel@vger.kernel.org, Amit Kucheria , Bjorn Andersson , Tony Lindgren , linux-arm-msm@vger.kernel.org, Lina Iyer , Sudeep Holla , Niklas Cassel , Souvik Chakravarty , "Raju P . L . S . S . S . N" , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, May 13, 2019 at 09:22:57PM +0200, Ulf Hansson wrote: > When the hierarchical CPU topology is used and when a CPU has been put > offline (hotplug), that same CPU prevents its PM domain and thus also > potential master PM domains, from being powered off. This is because genpd > observes the CPU's attached device as being active from a runtime PM point > of view. > > To deal with this, let's decrease the runtime PM usage count by calling > pm_runtime_put_sync_suspend() of the attached struct device when putting > the CPU offline. Consequentially, we must then increase the runtime PM > usage count, while putting the CPU online again. > Why is this firmware/driver specific ? Why can't this be dealt in core pm-domain ? I am concerned that if any other architectures or firmware method decides to use this feature, this need to be duplicated there. The way I see this is pure reference counting and is hardware/firmware/ driver agnostic and can be made generic. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel