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

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Date:   Wed, 31 Aug 2016 13:11:54 +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>,
        Peter Wu <peter@...ensteyn.nl>
Subject: Re: Kernel Freeze with American Megatrends BIOS

Am 30.08.2016 um 20:13 schrieb Ilia Mirkin:
> On Tue, Aug 30, 2016 at 2:02 PM, Roland Singer
> <roland.singer@...ertbit.com> wrote:
>> 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.
> 
> That's surprising. I believe there's an issue with the new logic when
> there's an HDMI audio subdevice. However that only appears if there's
> a cable plugged in, at least in the systems Peter tested. You should
> be able to see whether it's there or not with 'lspci'.
> 
> You can check for sure by looking in the vgaswitcheroo state. It
> should say DynOff when it's powered off.
> 
> Either way, I think using bbswitch + nouveau isn't supported by
> anyone, so if you want to use it that way, you're on your own. (You
> may want to load nouveau with runpm=0 so that nouveau doesn't try to
> manage the GPU suspend stuff.)
> 
>   -ilia
> 

Kernel 4.8-rc4:

While running lspci, following kernel log message was printed on the TTY:

  nouveau: 0000:01:00:0: priv: HUB0: 6013d4 0000573f (1f408200)
  nouveau: 0000:01:00:0: priv: HUB0: 10ecc0 ffffffff (1940822c)

This is my output of lspci:

00:00.0 Host bridge: Intel Corporation Skylake Host Bridge/DRAM Registers (rev 07)
00:01.0 PCI bridge: Intel Corporation Skylake PCIe Controller (x16) (rev 07)
00:02.0 VGA compatible controller: Intel Corporation HD Graphics 530 (rev 06)
00:08.0 System peripheral: Intel Corporation Skylake Gaussian Mixture Model
00:14.0 USB controller: Intel Corporation Sunrise Point-H USB 3.0 xHCI Controller (rev 31)
00:14.2 Signal processing controller: Intel Corporation Sunrise Point-H Thermal subsystem (rev 31)
00:15.0 Signal processing controller: Intel Corporation Sunrise Point-H Serial IO I2C Controller #0 (rev 31)
00:15.1 Signal processing controller: Intel Corporation Sunrise Point-H Serial IO I2C Controller #1 (rev 31)
00:16.0 Communication controller: Intel Corporation Sunrise Point-H CSME HECI #1 (rev 31)
00:1c.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #1 (rev f1)
00:1c.5 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #6 (rev f1)
00:1d.0 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #9 (rev f1)
00:1d.4 PCI bridge: Intel Corporation Sunrise Point-H PCI Express Root Port #13 (rev f1)
00:1e.0 Signal processing controller: Intel Corporation Sunrise Point-H Serial IO UART #0 (rev 31)
00:1f.0 ISA bridge: Intel Corporation Sunrise Point-H LPC Controller (rev 31)
00:1f.2 Memory controller: Intel Corporation Sunrise Point-H PMC (rev 31)
00:1f.3 Audio device: Intel Corporation Sunrise Point-H HD Audio (rev 31)
00:1f.4 SMBus: Intel Corporation Sunrise Point-H SMBus (rev 31)
01:00.0 3D controller: NVIDIA Corporation GM204M [GeForce GTX 970M] (rev a1)
3b:00.0 Network controller: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter (rev 32)
3d:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller (rev 01)