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 12E64C432C0 for ; Wed, 20 Nov 2019 12:19:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA588224FB for ; Wed, 20 Nov 2019 12:19:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="iY+OI6TP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729650AbfKTMTq (ORCPT ); Wed, 20 Nov 2019 07:19:46 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:41723 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728611AbfKTMTp (ORCPT ); Wed, 20 Nov 2019 07:19:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1574252383; 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=6tQSiatJZXoqislkFRtZVMOCpA4DqNNH30wH7vD5XN4=; b=iY+OI6TPbugU8YrTnWQQan/nA0tydHqH4MYa5t0Ks16kFz5+RDjBezCIDRyLqnpl5PdQBZ SHv/eNwrdJgJRkUU4L2Fl1xJ+ehB5cyJYw9iWBmMVWbX4t5fYTRtgrolCwbXsKzIoRZ5Pm aBzuDxx9Kp6ww54WsJtEUQw4+fILJ0g= Received: from mail-qv1-f71.google.com (mail-qv1-f71.google.com [209.85.219.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-7-_ispdzZQOnyNvwnHA8MDFA-1; Wed, 20 Nov 2019 07:19:42 -0500 Received: by mail-qv1-f71.google.com with SMTP id d12so16981278qvj.16 for ; Wed, 20 Nov 2019 04:19:42 -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=oWs1Gk0ow9/Ugo0hlEi2MnfVfxY0H34jjDGUnWVNnGE=; b=fsGZGWJnDqAvhsustT8MJ9I/moBsR3OSwrm380yRt0k9+/lFXwFXecqjEdZxwg5MX8 bUg+OYbSjqWW/gLmIU9d2NyJg1lY2FUUoo0CrGqYcSnN3oWSkqB+52qitJc9oHrORs4M +eJfIqtxz2wskqP01lmf/F29Lefw6T6HAkBraw6XUetNo4GWpDmk7KA/8YoZp+DLv6un DJobQF5vk9OUvzm2KT/IEKgycWHx0uK++4CaxfXWCZomnxa051jc/09BiDx4HaSCamjt zIo3MLPhpfcXgfeTDYiqpo8gb33Owa4bR4zhbTzfMRbAsoHLbqhEwkEEfh1187HU8wUP 49fQ== X-Gm-Message-State: APjAAAV1bNZUEeQilF++EYR1bMayGXAu8ULyHgBq0qViP4Ohbe5pFnBx Z5QckT+nmJdNPd/GL+7PPC73Py0TUJpEa7aM5IwlGuBbwYI4/mnb02umDHpUsGsRAIRMCdpzrr4 yhtgX9TEUbt4fMwuCAN2KTPfwRwxsWgWbF/aGIMcn X-Received: by 2002:ae9:f511:: with SMTP id o17mr2053121qkg.157.1574252382239; Wed, 20 Nov 2019 04:19:42 -0800 (PST) X-Google-Smtp-Source: APXvYqwYYwY32hdZJpgO9a9F96+AV3XWlzoWfPmJ3+IXJz1kjQ4tZP3raHWzLm6tC4nakFswJXw9vp47sPBOfFGfJkw= X-Received: by 2002:ae9:f511:: with SMTP id o17mr2053086qkg.157.1574252381985; Wed, 20 Nov 2019 04:19:41 -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 13:19:30 +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: _ispdzZQOnyNvwnHA8MDFA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It depends on the kernel being built with ACPI_REV_OVERRIDE_POSSIBLE=3Dy and acpi_rev_override=3D1 being set on the kernel command line On Wed, Nov 20, 2019 at 1:15 PM Rafael J. Wysocki wrote= : > > On Wed, Nov 20, 2019 at 1:10 PM Karol Herbst wrote: > > > > On Wed, Nov 20, 2019 at 1:06 PM Rafael J. Wysocki w= rote: > > > > > > On Wed, Nov 20, 2019 at 12:51 PM Karol Herbst wr= ote: > > > > > > > > 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 wro= te: > > > > > > > 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 tha= t tried > > > > > > > to work around some problematic behavior in Linux at one poin= t? > > > > > > > > > > > > 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 fo= r the > > > > > issue seems to be the AML in question, which means a firmware pro= blem. > > > > > > > > > > > > > And I disagree as this is a linux specific workaround and windows g= oes > > > > 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 afte= r > > > 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. > > I'm not sure what you are talking about. > > I'm taking specifically about the ((OSYS =3D=3D 0x07DF) && (_REV =3D=3D 0= x05)) > check mentioned by Mika which doesn't seem to depend on user input in > any way. >