Nouveau - Nov 2023 - [REGRESSION]: nouveau: Asynchronous wait on fence

On 28.10.23 04:46, Owen T. Heisler wrote:
> #regzbot introduced: d386a4b54607cf6f76e23815c2c9a3abc1d66882
> #regzbot link: https://gitlab.freedesktop.org/drm/nouveau/-/issues/180
> 
> ## Problem
> 
> 1. Connect external display to DVI port on dock and run X with both
> ?? displays in use.
> 2. Wait hours or days.
> 3. Suddenly the secondary Nvidia-connected display turns off and X stops
> ?? responding to keyboard/mouse input. In *some* cases it is possible to
> ?? switch to a virtual TTY with Ctrl+Alt+Fn and log in there. In any
> ?? case, shutdown/reboot after this happens is *usually* not successful
> ?? (forced power-off is required).
> 
> This started happening after the upgrade to Debian bullseye, and the
> problem remains with Debian bookworm.
> [...] 
Thanks for your report. With a bit of luck someone will look into this,
But I doubt it, as this report has some aspects why it might be ignored.
Mainly: (a) the report was about a stable/longterm kernel and (b)it's
afaics unclear if the problem even happens with the latest mainline
kernel. For details about these aspects, see:
https://linux-regtracking.leemhuis.info/post/frequent-reasons-why-linux-kernel-bug-reports-are-ignored/

You thus might want to check if the problem occurs with 6.6 -- and
ideally also check if reverting the culprit there fixes things for you.

That might help getting things rolling, but it's a pretty old
regression, which complicates things.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker'
hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
If I did something stupid, please tell me, as explained on that page.

On 10/31/23 04:18, Linux regression tracking (Thorsten Leemhuis)
wrote:
> Thanks for your report. With a bit of luck someone will look into this,
> But I doubt it, as this report has some aspects why it might be ignored.
> Mainly: (a) the report was about a stable/longterm kernel and (b)it's
> afaics unclear if the problem even happens with the latest mainline
> kernel.
> You thus might want to check if the problem occurs with 6.6 -- and
> ideally also check if reverting the culprit there fixes things for you.
Thorsten,

Thank you for your reply and suggestions. I will try (a) testing on 
mainline (when I tried before I was interrupted by another, unrelated 
regression) and (b) reverting the culprit commit there if I am able to 
reproduce the problem.

Thanks,
Owen

--
Owen T. Heisler
https://owenh.net

On 10/31/23 04:18, Linux regression tracking (Thorsten Leemhuis)
wrote:
> On 28.10.23 04:46, Owen T. Heisler wrote:
>> #regzbot introduced: d386a4b54607cf6f76e23815c2c9a3abc1d66882
>> #regzbot link: https://gitlab.freedesktop.org/drm/nouveau/-/issues/180
>>
>> ## Problem
>>
>> 1. Connect external display to DVI port on dock and run X with both
>>  ?? displays in use.
>> 2. Wait hours or days.
>> 3. Suddenly the secondary Nvidia-connected display turns off and X
stops
>>  ?? responding to keyboard/mouse input. In *some* cases it is possible
to
>>  ?? switch to a virtual TTY with Ctrl+Alt+Fn and log in there.
> You thus might want to check if the problem occurs with 6.6 -- and
> ideally also check if reverting the culprit there fixes things for you.
Hi Thorsten and others,

The problem also occurs with v6.6. Here is a decoded kernel log from an 
untainted kernel:

https://gitlab.freedesktop.org/drm/nouveau/uploads/c120faf09da46f9c74006df9f1d14442/async-wait-on-fence-180.log

The culprit commit does not revert cleanly on v6.6. I have not yet 
attempted to resolve the conflicts.

I have also updated the bug description at
<https://gitlab.freedesktop.org/drm/nouveau/-/issues/180>.

Thanks,
Owen

On 15.11.23 07:19, Owen T. Heisler wrote:
> On 10/31/23 04:18, Linux regression tracking (Thorsten Leemhuis) wrote:
>> On 28.10.23 04:46, Owen T. Heisler wrote:
>>> #regzbot introduced: d386a4b54607cf6f76e23815c2c9a3abc1d66882
>>> #regzbot link:
https://gitlab.freedesktop.org/drm/nouveau/-/issues/180
>>>
>>> ## Problem
>>>
>>> 1. Connect external display to DVI port on dock and run X with both
>>> ??? displays in use.
>>> 2. Wait hours or days.
>>> 3. Suddenly the secondary Nvidia-connected display turns off and X
stops
>>> ??? responding to keyboard/mouse input. In *some* cases it is
>>> possible to
>>> ??? switch to a virtual TTY with Ctrl+Alt+Fn and log in there.
> 
>> You thus might want to check if the problem occurs with 6.6 -- and
>> ideally also check if reverting the culprit there fixes things for you.
> 
> The problem also occurs with v6.6.
You meanwhile might want to give 6.7-rc as well on the off chance that
it improves things, even if that is unlikely.
> Here is a decoded kernel log from an
> untainted kernel:
> 
>
https://gitlab.freedesktop.org/drm/nouveau/uploads/c120faf09da46f9c74006df9f1d14442/async-wait-on-fence-180.log
> 
> The culprit commit does not revert cleanly on v6.6. I have not yet
> attempted to resolve the conflicts.
> 
> I have also updated the bug description at
> <https://gitlab.freedesktop.org/drm/nouveau/-/issues/180>.
Maybe one of the nouveau developer can take a quick look at
d386a4b54607cf and suggest a simple way to revert it in latest mainline.
Maybe just removing the main chunk of code that is added is all that it
takes.

Ciao, Thorsten