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,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 C84E4C433DF for ; Fri, 12 Jun 2020 20:48:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A10F020801 for ; Fri, 12 Jun 2020 20:48:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726368AbgFLUsI (ORCPT ); Fri, 12 Jun 2020 16:48:08 -0400 Received: from mga03.intel.com ([134.134.136.65]:44482 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726268AbgFLUsH (ORCPT ); Fri, 12 Jun 2020 16:48:07 -0400 IronPort-SDR: T7EW+TBF+4jkSITuM1sJRqvEMPMwoc5BeoBbSP7NiKovzhr0T1bzkpq2Ofz2pvO2K/iCn/46yh p7281TyMm5CQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jun 2020 13:48:07 -0700 IronPort-SDR: LFgYyzHi1cf6/D4dh3wIX+ANgQ30imkG5tn9trlkftoohDgt4bJgNWyrwJyDfgLr3bATu/+5G8 CdBnIvZrXwzg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,504,1583222400"; d="scan'208";a="307352135" Received: from linux.intel.com ([10.54.29.200]) by orsmga008.jf.intel.com with ESMTP; 12 Jun 2020 13:48:06 -0700 Received: from debox1-desk2.jf.intel.com (debox1-desk2.jf.intel.com [10.54.75.16]) by linux.intel.com (Postfix) with ESMTP id C7EDF5803C5; Fri, 12 Jun 2020 13:48:06 -0700 (PDT) From: "David E. Box" To: shyjumon.n@intel.com, rjw@rjwysocki.net, lenb@kernel.org, bhelgaas@google.com, dan.j.williams@intel.com, kbusch@kernel.org, axboe@fb.com, hch@lst.de, sagi@grimberg.me Cc: "David E. Box" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-nvme@lists.infradead.org Subject: [PATCH V2 0/2] nvme: Add support for ACPI StorageD3Enable property Date: Fri, 12 Jun 2020 13:48:18 -0700 Message-Id: <20200612204820.20111-1-david.e.box@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200428003214.3764-1-david.e.box@linux.intel.com> References: <20200428003214.3764-1-david.e.box@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch set implements a solution for a BIOS hack used on some currently shipping Intel systems to address issues with power management policy decisions concerning PCIe NVMe drives. Some newer Intel platforms, like some Comet Lake systems, require that PCIe devices use D3 when doing suspend-to-idle in order to allow the platform to realize maximum power savings. This is particularly needed to support ATX power supply shutdown on desktop systems. In order to ensure this happens for root ports with storage devices, Microsoft apparently created this ACPI _DSD property as a way to override their driver policy. To my knowledge this property has not been discussed with the NVME specification body. Though the solution is not ideal, it addresses a problem that also affects Linux since the NVMe driver's default policy of using NVMe APST during suspend-to-idle would lead to higher power consumption for these platforms. Patch 1 provides a symbol in the PCI/ACPI layer to read the property. Patch 2 uses the symbol in the NVMe driver to select D3 as a quirk if set. Changes from V2: - Export the pci_acpi_storage_d3 function for use by drivers as needed instead of modifying the pci header. - Add missing put on acpi device handle. - Add 'noacpi' module parameter to allow undoing this change. - Add info message that this is a platform quirk. David E. Box (2): PCI: Add ACPI StorageD3Enable _DSD support drivers/nvme: Add support for ACPI StorageD3Enable property drivers/acpi/property.c | 3 +++ drivers/nvme/host/pci.c | 14 ++++++++++ drivers/pci/pci-acpi.c | 59 +++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 2 ++ 4 files changed, 78 insertions(+) -- 2.20.1