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=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 4F3FBC432C0 for ; Wed, 20 Nov 2019 12:10:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28C82224C1 for ; Wed, 20 Nov 2019 12:10:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="CecSWFJe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729201AbfKTMKG (ORCPT ); Wed, 20 Nov 2019 07:10:06 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:52034 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727900AbfKTMKG (ORCPT ); Wed, 20 Nov 2019 07:10:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1574251804; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=knFBJ+jIledi9b7Ia4deKRuiHotpqtnvRJzVLFu8J74=; b=CecSWFJeDa2330RCBeYrqMKU5Qlb17mU2xfUcHP0NdImDrsZVUiJkMjT4gfmyd8i303HPe furWfkp9gNlZ/Ro/7LAFGxQNu2ZRJ58WhzHQ3LnFoBbwpPnt5yEKsUPHRxYzCsNEvEzi+p +fDD46WQEy6IzSNj2fFMA2cFkWE5BFM= Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-182-T1v1ADisOauAYS5F5upJVg-1; Wed, 20 Nov 2019 07:10:03 -0500 Received: by mail-qt1-f200.google.com with SMTP id 6so16914107qtu.7 for ; Wed, 20 Nov 2019 04:10:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=7p4rYZMTKBgx0gRU2Y/8e1TMHUDBS8YuAIk55PkbbCM=; b=LQURchMCfKMiAAPT9TohL7ksz5EaKkA5ogATGiLRAaD6CQWTGouLGtyjcizH0KQsSn a+cZuM8J/l0/j0Y4atOc5VRGteNom8ibJqkwCXsqhHAms7ZDYxG+4vqW9SDjxLOGqcv1 ncYSc9hTn7DXYmwZ1zV27GuszRCwldWMxiZ/cDl7A/8EG8ZOVCQzftshQZ9us9qzjshw ManFnNQ9c+abY2aPI+/rVM6T4RISBtp/ZSVYC6IpMcpg0SLzl4J7Q4He1z9eWjjKndII kxrti2NnF6Qt9WUqDDCeEzJp124fF7BXm8d1nDIaMZldhd59rgzyGdnvWi6ebIbUyONN AZGQ== X-Gm-Message-State: APjAAAU9mB0/cj3DOFcW3mfM/zrHdJdlM0rfAvkXU3bdiLuL8AHo+X1A SmVp8IoHpABoD8E2PztaK7V3o1znBHsFoWNZ7FTDp3r8+7FdMpq7PhAc/OpvL5q/lLv+F9qiaIF wFrcWCKr3W+IabpsvfwFVxGgWD+GE6ws55z8= X-Received: by 2002:a37:9083:: with SMTP id s125mr2035556qkd.192.1574251802834; Wed, 20 Nov 2019 04:10:02 -0800 (PST) X-Google-Smtp-Source: APXvYqz4S4Yg7VICuKWth27RQHwQbnKmUWBvPlof4TRp3+1St7VECDM0n728MYoDSOHL10176AueXActPrjMWKfP+xo= X-Received: by 2002:a37:9083:: with SMTP id s125mr2035532qkd.192.1574251802589; Wed, 20 Nov 2019 04:10:02 -0800 (PST) MIME-Version: 1.0 References: <20191017121901.13699-1-kherbst@redhat.com> <20191119214955.GA223696@google.com> <20191120101816.GX11621@lahna.fi.intel.com> <20191120112212.GA11621@lahna.fi.intel.com> In-Reply-To: From: Karol Herbst Date: Wed, 20 Nov 2019 13:09:51 +0100 Message-ID: Subject: Re: [PATCH v4] pci: prevent putting nvidia GPUs into lower device states on certain intel bridges To: "Rafael J. Wysocki" Cc: Mika Westerberg , Bjorn Helgaas , LKML , Lyude Paul , "Rafael J . Wysocki" , Linux PCI , Linux PM , dri-devel , nouveau , Dave Airlie , Mario Limonciello X-MC-Unique: T1v1ADisOauAYS5F5upJVg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Wed, Nov 20, 2019 at 1:06 PM Rafael J. Wysocki wrote= : > > On Wed, Nov 20, 2019 at 12:51 PM Karol Herbst wrote: > > > > On Wed, Nov 20, 2019 at 12:48 PM Rafael J. Wysocki = wrote: > > > > > > On Wed, Nov 20, 2019 at 12:22 PM Mika Westerberg > > > wrote: > > > > > > > > On Wed, Nov 20, 2019 at 11:52:22AM +0100, Rafael J. Wysocki wrote: > > > > > On Wed, Nov 20, 2019 at 11:18 AM Mika Westerberg > > > > > wrote: > > > > > > > > [cut] > > > > > > > > > > > Oh, so does it look like we are trying to work around AML that tr= ied > > > > > to work around some problematic behavior in Linux at one point? > > > > > > > > Yes, it looks like so if I read the ASL right. > > > > > > OK, so that would call for a DMI-based quirk as the real cause for th= e > > > issue seems to be the AML in question, which means a firmware problem= . > > > > > > > And I disagree as this is a linux specific workaround and windows goes > > that path and succeeds. This firmware based workaround was added, > > because it broke on Linux. > > Apparently so at the time it was added, but would it still break after > the kernel changes made since then? > > Moreover, has it not become harmful now? IOW, wouldn't it work after > removing the "Linux workaround" from the AML? > > The only way to verify that I can see would be to run the system with > custom ACPI tables without the "Linux workaround" in the AML in > question. > the workaround is not enabled by default, because it has to be explicitly enabled by the user.