From patchwork Thu Aug 8 08:36:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 11083549 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4D1911399 for ; Thu, 8 Aug 2019 08:36:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3B61428B13 for ; Thu, 8 Aug 2019 08:36:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2EF1328B1B; Thu, 8 Aug 2019 08:36:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9406028B13 for ; Thu, 8 Aug 2019 08:36:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731065AbfHHIgl (ORCPT ); Thu, 8 Aug 2019 04:36:41 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:46339 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726187AbfHHIgl (ORCPT ); Thu, 8 Aug 2019 04:36:41 -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 20bffa7542b3d3cc; Thu, 8 Aug 2019 10:36:38 +0200 From: "Rafael J. Wysocki" To: linux-nvme Cc: Keith Busch , Mario Limonciello , Kai-Heng Feng , Keith Busch , Christoph Hellwig , Sagi Grimberg , Linux PM , Linux Kernel Mailing List , Rajat Jain , Linux PCI , Bjorn Helgaas Subject: [PATCH] nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled Date: Thu, 08 Aug 2019 10:36:37 +0200 Message-ID: <2583975.4sIyE3leJj@kreacher> In-Reply-To: <20190731221956.GB15795@localhost.localdomain> References: <4323ed84dd07474eab65699b4d007aaf@AUSX13MPC105.AMER.DELL.COM> <47415939.KV5G6iaeJG@kreacher> <20190730144134.GA12844@localhost.localdomain> <100ba4aff1c6434a81e47774ab4acddc@AUSX13MPC105.AMER.DELL.COM> <8246360B-F7D9-42EB-94FC-82995A769E28@canonical.com> <20190730191934.GD13948@localhost.localdomain> <7d3e0b8ba1444194a153c93faa1cabb3@AUSX13MPC105.AMER.DELL.COM> <20190730213114.GK13948@localhost.localdomain> <20190731221956.GB15795@localhost.localdomain> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- This is an update of the following patch: https://patchwork.kernel.org/patch/11081791/ going with the subject matching the changes in the patch. This also addresses style-related comments from Christoph and follows the Keith's advice to use pci_upstream_bridge() to get to the upstream bridge of the device. Thanks! --- drivers/nvme/host/pci.c | 15 +++++++++++---- drivers/pci/pcie/aspm.c | 20 ++++++++++++++++++++ include/linux/pci.h | 2 ++ 3 files changed, 33 insertions(+), 4 deletions(-) Index: linux-pm/drivers/nvme/host/pci.c =================================================================== --- linux-pm.orig/drivers/nvme/host/pci.c +++ linux-pm/drivers/nvme/host/pci.c @@ -2846,7 +2846,7 @@ static int nvme_resume(struct device *de struct nvme_dev *ndev = pci_get_drvdata(to_pci_dev(dev)); struct nvme_ctrl *ctrl = &ndev->ctrl; - if (pm_resume_via_firmware() || !ctrl->npss || + if (ndev->last_ps == U32_MAX || nvme_set_power_state(ctrl, ndev->last_ps) != 0) nvme_reset_ctrl(ctrl); return 0; @@ -2859,6 +2859,8 @@ static int nvme_suspend(struct device *d struct nvme_ctrl *ctrl = &ndev->ctrl; int ret = -EBUSY; + ndev->last_ps = U32_MAX; + /* * The platform does not remove power for a kernel managed suspend so * use host managed nvme power settings for lowest idle power if @@ -2866,8 +2868,14 @@ static int nvme_suspend(struct device *d * shutdown. But if the firmware is involved after the suspend or the * device does not support any non-default power states, shut down the * device fully. + * + * If ASPM is not enabled for the device, shut down the device and allow + * the PCI bus layer to put it into D3 in order to take the PCIe link + * down, so as to allow the platform to achieve its minimum low-power + * state (which may not be possible if the link is up). */ - if (pm_suspend_via_firmware() || !ctrl->npss) { + if (pm_suspend_via_firmware() || !ctrl->npss || + !pcie_aspm_enabled(pdev)) { nvme_dev_disable(ndev, true); return 0; } @@ -2880,9 +2888,8 @@ static int nvme_suspend(struct device *d ctrl->state != NVME_CTRL_ADMIN_ONLY) goto unfreeze; - ndev->last_ps = 0; ret = nvme_get_power_state(ctrl, &ndev->last_ps); - if (ret < 0) + if (ret < 0 || ndev->last_ps == U32_MAX) goto unfreeze; ret = nvme_set_power_state(ctrl, ctrl->npss); Index: linux-pm/drivers/pci/pcie/aspm.c =================================================================== --- linux-pm.orig/drivers/pci/pcie/aspm.c +++ linux-pm/drivers/pci/pcie/aspm.c @@ -1170,6 +1170,26 @@ static int pcie_aspm_get_policy(char *bu module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy, NULL, 0644); +/* + * pcie_aspm_enabled - Return the mask of enabled ASPM link states. + * @pci_device: Target device. + */ +u32 pcie_aspm_enabled(struct pci_dev *pci_device) +{ + struct pci_dev *bridge = pci_upstream_bridge(pci_device); + u32 ret; + + if (!bridge) + return 0; + + mutex_lock(&aspm_lock); + ret = bridge->link_state ? bridge->link_state->aspm_enabled : 0; + mutex_unlock(&aspm_lock); + + return ret; +} + + #ifdef CONFIG_PCIEASPM_DEBUG static ssize_t link_state_show(struct device *dev, struct device_attribute *attr, Index: linux-pm/include/linux/pci.h =================================================================== --- linux-pm.orig/include/linux/pci.h +++ linux-pm/include/linux/pci.h @@ -1567,8 +1567,10 @@ extern bool pcie_ports_native; #ifdef CONFIG_PCIEASPM bool pcie_aspm_support_enabled(void); +u32 pcie_aspm_enabled(struct pci_dev *pci_device); #else static inline bool pcie_aspm_support_enabled(void) { return false; } +static inline u32 pcie_aspm_enabled(struct pci_dev *pci_device) { return 0; } #endif #ifdef CONFIG_PCIEAER