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 A3843E77188 for ; Fri, 3 Jan 2025 07:28:13 +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=Z9lAtYQq3A9Cj5itl6GpOZkPFgHbN6tQezuB+WO8P8g=; b=AO3FeN2P0hpOwTOgfcbtaTg2Ip YHWnx08SLGz2MBHgaV/rSeG3LLfm64+/pCWvnvYs72eHuPnDXkgH79+ii4b2NiGOtQwiw0rqGewbl zw7JsQKYp8UBpX5oXteUiU5XBLOesvjINIVJvHMt02OQ2hVG1/BTBUMPbwRiswrnXUEryruwhP7u0 9JCeCpDbeZd+CmHlPe8BXmKmjcynXIar3p+hEGA6bIXAnZnRTlaj0PbNSt/U8rvMa/9zzOX8oapvb Aws86YEoqcUZFUqpsm6Yn8Y/BATBc0wOsuLASoDWwsfVo2N/TX8WCpU3kUZ/qUFCDtujAGx69JJIM YW9kAV4w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tTc6O-0000000CKrq-0k4r; Fri, 03 Jan 2025 07:28:12 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tTc6M-0000000CKqt-0TE2 for linux-nvme@lists.infradead.org; Fri, 03 Jan 2025 07:28:11 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 981C868BEB; Fri, 3 Jan 2025 08:28:05 +0100 (CET) Date: Fri, 3 Jan 2025 08:28:05 +0100 From: Christoph Hellwig To: Konrad Dybcio Cc: "Rafael J. Wysocki" , Christoph Hellwig , Manivannan Sadhasivam , 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: <20250103072805.GB28920@lst.de> References: <20241209143821.m4dahsaqeydluyf3@thinkpad> <20241212055920.GB4825@lst.de> <13662231.uLZWGnKmhe@rjwysocki.net> <20241212151354.GA7708@lst.de> <20241214063023.4tdvjbqd2lrylb7o@thinkpad> <20241216162303.GA26434@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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-20250102_232810_308293_84D17D16 X-CRM114-Status: GOOD ( 20.50 ) 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 Fri, Dec 20, 2024 at 04:15:21PM +0100, Konrad Dybcio wrote: > The Qualcomm platform (or class of platforms) we're looking at with this > specific issue requires PCIe (implying NVMe) shutdown for S2RAM. > > The S2RAM entry mechanism is unfortunately misrepresented as an S2Idle > state by Linux as of today, and I'm trying really hard to convince some > folks to let me describe it correctly, with little success so far.. Well, not advertizing the right mechanism isn't going to cause havoc to any scheme. > That is the real underlying issue and once/if it's solved, this patch > will not be necessary. Well, maybe this thread gave good enough fodder to finally fix it? > > > In theory, ACPI S3 or hibernation may request that, but I've never > > seen it happen in practice. > > > > Suspend-to-idle on x86 may want devices to end up in specific power > > states in order to be able to switch the entire platform into a deep > > energy-saving mode, but that's never been D3cold so far. > > In our case the plug is only pulled in S2RAM, otherwise the best we can > do is just turn off the devices individually to decrease the overall > power draw FYI, going to D3 for S2RAM seems perfectly reasonable from the NVMe POV.