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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 7F7ADC32751 for ; Wed, 7 Aug 2019 10:14:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5716821E6C for ; Wed, 7 Aug 2019 10:14:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728091AbfHGKOL (ORCPT ); Wed, 7 Aug 2019 06:14:11 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:49060 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725991AbfHGKOL (ORCPT ); Wed, 7 Aug 2019 06:14:11 -0400 Received: from 79.184.254.29.ipv4.supernova.orange.pl (79.184.254.29) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.275) id 015a7a6c70140c25; Wed, 7 Aug 2019 12:14:08 +0200 From: "Rafael J. Wysocki" To: Keith Busch Cc: Mario Limonciello , Kai-Heng Feng , Keith Busch , Christoph Hellwig , Sagi Grimberg , linux-nvme , Linux PM , Linux Kernel Mailing List , Rajat Jain , Linux PCI , Bjorn Helgaas Subject: Re: [PATCH] nvme-pci: Do not prevent PCI bus-level PM from being used Date: Wed, 07 Aug 2019 12:14:08 +0200 Message-ID: <2081634.8PS0KMhuBW@kreacher> In-Reply-To: <1893355.EP2830DdO9@kreacher> References: <4323ed84dd07474eab65699b4d007aaf@AUSX13MPC105.AMER.DELL.COM> <20190731221956.GB15795@localhost.localdomain> <1893355.EP2830DdO9@kreacher> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, August 7, 2019 11:53:44 AM CEST Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > One of the modifications made by commit d916b1be94b6 ("nvme-pci: use > host managed power state for suspend") was adding a pci_save_state() > call to nvme_suspend() in order to prevent the PCI bus-level PM from > being applied to the suspended NVMe devices, but if ASPM is not > enabled for the target NVMe device, that causes its PCIe link to stay > up and the platform may not be able to get into its optimum low-power > state because of that. > > For example, if ASPM is disabled for the NVMe drive (PC401 NVMe SK > hynix 256GB) in my Dell XPS13 9380, leaving it in D0 during > suspend-to-idle prevents the SoC from reaching package idle states > deeper than PC3, which is way insufficient for system suspend. > > To address this shortcoming, make nvme_suspend() check if ASPM is > enabled for the target device and fall back to full device shutdown > and PCI bus-level PM if that is not the case. > > Fixes: d916b1be94b6 ("nvme-pci: use host managed power state for suspend") > Link: https://lore.kernel.org/linux-pm/2763495.NmdaWeg79L@kreacher/T/#t > Signed-off-by: Rafael J. Wysocki > --- I should have used a better subject for this patch. I'll resend it with a changed subject later, but for now I would like to collect opinions about it (if any). Cheers!