linux-kernel - Re: [PATCH v3] pci: prevent putting nvidia GPUs into lower device states on certain intel bridges

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20191021140852.GM2819@lahna.fi.intel.com>
Date:   Mon, 21 Oct 2019 17:08:52 +0300
From:   Mika Westerberg <mika.westerberg@...el.com>
To:     Karol Herbst <kherbst@...hat.com>
Cc:     Bjorn Helgaas <helgaas@...nel.org>,
        "Rafael J . Wysocki" <rjw@...ysocki.net>,
        LKML <linux-kernel@...r.kernel.org>,
        Lyude Paul <lyude@...hat.com>,
        Linux PCI <linux-pci@...r.kernel.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        dri-devel <dri-devel@...ts.freedesktop.org>,
        nouveau <nouveau@...ts.freedesktop.org>,
        Linux ACPI Mailing List <linux-acpi@...r.kernel.org>
Subject: Re: [PATCH v3] pci: prevent putting nvidia GPUs into lower device
 states on certain intel bridges

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.