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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 898C9CA9EAF for ; Mon, 21 Oct 2019 15:46:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6132120873 for ; Mon, 21 Oct 2019 15:46:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729599AbfJUPqZ (ORCPT ); Mon, 21 Oct 2019 11:46:25 -0400 Received: from mga06.intel.com ([134.134.136.31]:15381 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727101AbfJUPqY (ORCPT ); Mon, 21 Oct 2019 11:46:24 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Oct 2019 08:46:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,324,1566889200"; d="scan'208";a="209463506" Received: from lahna.fi.intel.com (HELO lahna) ([10.237.72.157]) by fmsmga001.fm.intel.com with SMTP; 21 Oct 2019 08:46:07 -0700 Received: by lahna (sSMTP sendmail emulation); Mon, 21 Oct 2019 18:46:06 +0300 Date: Mon, 21 Oct 2019 18:46:06 +0300 From: Mika Westerberg To: Karol Herbst Cc: Bjorn Helgaas , "Rafael J . Wysocki" , LKML , Lyude Paul , Linux PCI , Linux PM , dri-devel , nouveau , Linux ACPI Mailing List Subject: Re: [PATCH v3] pci: prevent putting nvidia GPUs into lower device states on certain intel bridges Message-ID: <20191021154606.GT2819@lahna.fi.intel.com> References: <20191016213722.GA72810@google.com> <20191021133328.GI2819@lahna.fi.intel.com> <20191021140852.GM2819@lahna.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Mon, Oct 21, 2019 at 04:49:09PM +0200, Karol Herbst wrote: > On Mon, Oct 21, 2019 at 4:09 PM Mika Westerberg > wrote: > > > > On Mon, Oct 21, 2019 at 03:54:09PM +0200, Karol Herbst wrote: > > > > I really would like to provide you more information about such > > > > workaround but I'm not aware of any ;-) I have not seen any issues like > > > > this when D3cold is properly implemented in the platform. That's why > > > > I'm bit skeptical that this has anything to do with specific Intel PCIe > > > > ports. More likely it is some power sequence in the _ON/_OFF() methods > > > > that is run differently on Windows. > > > > > > yeah.. maybe. I really don't know what's the actual root cause. I just > > > know that with this workaround it works perfectly fine on my and some > > > other systems it was tested on. Do you know who would be best to > > > approach to get proper documentation about those methods and what are > > > the actual prerequisites of those methods? > > > > Those should be documented in the ACPI spec. Chapter 7 should explain > > power resources and the device power methods in detail. > > either I looked up the wrong spec or the documentation isn't really > saying much there. Well it explains those methods, _PSx, _PRx and _ON()/_OFF(). In case of PCIe device you also want to check PCIe spec. PCIe 5.0 section 5.8 "PCI Function Power State Transitions" has a picture about the supported power state transitions and there we can find that function must be in D3hot before it can be transitioned into D3cold so if the _OFF() for example blindly assumes that the device is in D0 when it is called, it is a bug in the BIOS. BTW, where can I find acpidump of such system?