From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mika Westerberg Subject: Re: [PATCH v3] pci: prevent putting nvidia GPUs into lower device states on certain intel bridges Date: Mon, 21 Oct 2019 17:08:52 +0300 Message-ID: <20191021140852.GM2819@lahna.fi.intel.com> References: <20191016213722.GA72810@google.com> <20191021133328.GI2819@lahna.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Karol Herbst Cc: Bjorn Helgaas , "Rafael J . Wysocki" , LKML , Lyude Paul , Linux PCI , Linux PM , dri-devel , nouveau , Linux ACPI Mailing List List-Id: dri-devel@lists.freedesktop.org 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.