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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 1A7A5C83001 for ; Tue, 28 Apr 2020 15:27:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 023B7206E2 for ; Tue, 28 Apr 2020 15:27:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728191AbgD1P1x (ORCPT ); Tue, 28 Apr 2020 11:27:53 -0400 Received: from mga18.intel.com ([134.134.136.126]:64740 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728147AbgD1P1x (ORCPT ); Tue, 28 Apr 2020 11:27:53 -0400 IronPort-SDR: 9k1KmL5It0WMjCTJopVCfWUgFlm47pMqB6RZxA8al4pkM4pxnFUSZmduJLmozlBPLGGWa+Bt/t i06yC9brxIvA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2020 08:27:51 -0700 IronPort-SDR: UNnU/pmBRK2OkJ3qAl3VQ1s9gW2e4JpF7lPfFAiI7yqU9sbKROyoly5hqXVOgWqX5u3I4vC1Fw PsaBRrDB9MQg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,328,1583222400"; d="scan'208";a="282179569" Received: from linux.intel.com ([10.54.29.200]) by fmsmga004.fm.intel.com with ESMTP; 28 Apr 2020 08:27:50 -0700 Received: from debox1-desk1.jf.intel.com (debox1-desk1.jf.intel.com [10.7.201.137]) by linux.intel.com (Postfix) with ESMTP id 38EE4580CC1; Tue, 28 Apr 2020 08:27:50 -0700 (PDT) Message-ID: Subject: Re: [PATCH 0/2] Add support for StorageD3Enable _DSD property From: "David E. Box" Reply-To: david.e.box@linux.intel.com To: Christoph Hellwig Cc: rjw@rjwysocki.net, lenb@kernel.org, bhelgaas@google.com, kbusch@kernel.org, axboe@fb.com, sagi@grimberg.me, linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org Date: Tue, 28 Apr 2020 08:27:50 -0700 In-Reply-To: <20200428142247.GB5439@lst.de> References: <20200428003214.3764-1-david.e.box@linux.intel.com> <20200428051312.GB17146@lst.de> <20200428142247.GB5439@lst.de> Organization: David E. Box Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.3 (3.34.3-1.fc31) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Tue, 2020-04-28 at 16:22 +0200, Christoph Hellwig wrote: > On Tue, Apr 28, 2020 at 07:09:59AM -0700, David E. Box wrote: > > > I'm not sure who came up with the idea to put this into ACPI, but > > > it > > > belongs into NVMe. Please talk to the NVMe technical working > > > group > > > instead of trying to overrules them in an unrelated group that > > > doesn't > > > apply to all of PCIe. > > > > Agreed that this is not ideal since it does not apply to all of > > PCIe. > > But as the property already exists on shipping systems, we need to > > be > > able to read it in the NVMe driver and the patch is consitent with > > the > > way properties under PCI ports are read. > > The point is that it is not the BIOSes job do decide how Linux does > power management. For example D3 has really horrible entry and exit > latencies in many cases, and will lead to higher power usage. The platform can know which pm policies will save the most power. But since the solution doesn't apply to all PCIe devices (despite BIOS specifying it that way) I'll withdraw this patch. Thanks. David