[6.1][regression] after commit dd80d9c8eecac8c516da5b240d01a35660ba6cb6 some games (Cyberpunk 2077, Forza Horizon 4/5) hang at start

[Christian König]

Hi Mikhail,

Am 30.10.22 um 23:05 schrieb Mikhail Gavrilov:
> On Wed, Oct 26, 2022 at 12:29 PM Christian König
> <christian.koenig at amd.com> wrote:
>> Attached is the original test patch rebased on current amd-staging-drm-next.
>>
>> Can you test if this is enough to make sure that the games start without
>> crashing by fetching the userptrs?
> 1. Over the past week the list of games affected by this issue updated
> with new games: The Outlast Trials, Gotham Knights, Sackboy: A Big
> Adventure.
>
> 2. I tested the patch and it really solves the problem with the launch
> of all the listed games and does not create new problems.
>
> 3. The only thing I noticed is that in the game Sackboy: A Big
> Adventure, when using the kernel built from the commit
> b229b6ca5abbd63ff40c1396095b1b36b18139c3 + the attached patch, I can’t
> connect to friend coop session due to the steam client hangs. The
> kernel built from commit 736ec9fadd7a1fde8480df7e5cfac465c07ff6f3
> (this is the commit prior to dd80d9c8eecac8c516da5b240d01a35660ba6cb6)
> free of this problem.
>
> I need to spend some more time to find the commit after which leads to
> hanging [3] the steam client.

Let's focus on one problem at a time.

The issue here is that somehow userptr handling became racy after we 
removed the lock, but I don't see why.

We need to fix this ASAP since it is probably a much wider problem and 
the additional lock just hides it somehow.

Going to provide you with an updated patch tomorrow.

Thanks,
Christian.

>
> Thanks.
>