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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 8C627E7717F for ; Mon, 16 Dec 2024 16:23:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=u0UNzOfWZeJRJ1OOlRdob0AkneS1135Q5X3pszp7vpk=; b=nVeAMRksGfYxMZQ6XUVnn4V2hZ dJAcWqB7Dwo8cbMdHXQ8QsjcN3qkLKs7zFjL3eID04eqv1jgJT3OPQc+wstary1cCPScp14vNzhOJ LvMSH8TESYEwoBfrOASnwbIDcNPrBxiGXVDOoG1PNcQEgrsSvHxz2l8qA1iKM51qXsMUtQoQOQH1l 85/rAdZdCrXFgMWvgqnsVarAyXG27+gHwzeXTwQXniNPUBg1jGM7ykmGac8oMZj97DlWuGp63mgCY xbi3dAXL4Ba5TMHNMtsVvSM9xQlgHwrRha6K6Q4fMaK1g2GVQE16jDHvJDts7KzOgLTis0q8DYVoi Kc1NrCSA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tNDsF-0000000AZDx-0miy; Mon, 16 Dec 2024 16:23:11 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tNDsD-0000000AZDK-1dnL for linux-nvme@lists.infradead.org; Mon, 16 Dec 2024 16:23:10 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id B958768C4E; Mon, 16 Dec 2024 17:23:03 +0100 (CET) Date: Mon, 16 Dec 2024 17:23:03 +0100 From: Christoph Hellwig To: Manivannan Sadhasivam Cc: "Rafael J. Wysocki" , Christoph Hellwig , Ulf Hansson , "Rafael J. Wysocki" , Bjorn Helgaas , kbusch@kernel.org, axboe@kernel.dk, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, andersson@kernel.org, konradybcio@kernel.org, Len Brown , linux-pm@vger.kernel.org Subject: Re: [PATCH] nvme-pci: Shutdown the device if D3Cold is allowed by the user Message-ID: <20241216162303.GA26434@lst.de> References: <20241205232900.GA3072557@bhelgaas> <20241209143821.m4dahsaqeydluyf3@thinkpad> <20241212055920.GB4825@lst.de> <13662231.uLZWGnKmhe@rjwysocki.net> <20241212151354.GA7708@lst.de> <20241214063023.4tdvjbqd2lrylb7o@thinkpad> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241214063023.4tdvjbqd2lrylb7o@thinkpad> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241216_082309_573251_A66B6E32 X-CRM114-Status: GOOD ( 13.46 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Sat, Dec 14, 2024 at 12:00:23PM +0530, Manivannan Sadhasivam wrote: > We need a PM core API that tells the device drivers when it is safe to powerdown > the devices. The usecase here is with PCIe based NVMe devices but the problem is > applicable to other devices as well. Maybe I'm misunderstanding things, but I think the important part is to indicate when a suspend actually MUST put the device into D3. Because doing that should always be safe, but not always optimal.