linux-kernel - Re: Kernel Freeze with American Megatrends BIOS

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Message-ID: <1c761bab-f82b-3f43-c4f0-c7a8eff94f25@desertbit.com>
Date:   Tue, 30 Aug 2016 20:02:11 +0200
From:   Roland Singer <roland.singer@...ertbit.com>
To:     Ilia Mirkin <imirkin@...m.mit.edu>
Cc:     Emil Velikov <emil.l.velikov@...il.com>,
        Bjorn Helgaas <helgaas@...nel.org>,
        Linux PCI <linux-pci@...r.kernel.org>,
        "Linux-Kernel@...r. Kernel. Org" <linux-kernel@...r.kernel.org>,
        ML dri-devel <dri-devel@...ts.freedesktop.org>,
        "linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>
Subject: Re: Kernel Freeze with American Megatrends BIOS

I configured bbswitch to not set any states automatically...
So it's possible to obtain and verify the GPU power state.

However I removed the bbswitch module and booted with nouveau.

Kernel 4.7.2: nouveau switches the discrete GPU off.
              I can't trigger the freeze, because bbswitch is missing.
              I'll work with the system and see if it will freeze.

Kernel 4.8-rc4: nouveau does not care about the power state and
                the discrete GPU is never switched off. I will notice
                this, because the second cooling FAN will stop...
                Same log messages as send before.


Am 30.08.2016 um 19:43 schrieb Ilia Mirkin:
> On Tue, Aug 30, 2016 at 1:37 PM, Roland Singer
> <roland.singer@...ertbit.com> wrote:
>> My conclusion:
>>
>> 1. Nouveau has couple of problems with GTX 9** M Nvidia GPUs.
>>    I would love to help here.
> 
> nouveau + bbswitch will always end in tears. You're going behind the
> driver's back and messing around with state it believes it is
> managing. What if you just use nouveau and let it auto-power-off the
> GPU like it's designed to, with v4.8-rc?
> 
>   -ilia
>