[REGRESSION]: nouveau: Asynchronous wait on fence

[Linux regression tracking (Thorsten Leemhuis)]

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