Trouble with TTM patches w/nouveau in linux-next

[Christian König]

Hi Mikko,

strange sounds like Nouveau was somehow also using the GEM workaround 
for VMWGFX as well.

But -12 means -ENOMEM which doesn't fits into the picture.

I will try with a G710, but if that doesn't yields anything I need some 
more input from you.

Thanks for the report,
Christian.


Am 09.06.21 um 15:47 schrieb Mikko Perttunen:
> Hi,
>
> I'm observing nouveau not initializing recently on linux-next on my 
> Tegra186 Jetson TX2 board. Specifically it looks like BO allocation is 
> failing when initializing the sync subsystem:
>
> [   21.858149] nouveau 17000000.gpu: DRM: failed to initialise sync 
> subsystem, -28
>
> I have been bisecting and I have found two patches that affect this. 
> Firstly, things first break on
>
> d02117f8efaa drm/ttm: remove special handling for non GEM drivers
>
> starting to return error code -12. Then, at
>
> d79025c7f5e3 drm/ttm: always initialize the full ttm_resource v2
>
> the error code changes to the above -28.
>
> If I checkout one commit prior to d79025c7f5e3 and revert 
> d02117f8efaa, things work again. There are a bunch of other TTM 
> commits between this and HEAD, so reverting these on top of HEAD 
> doesn't work. However, I checked that both yesterday's and today's 
> nexts are also broken.
>
> Thank you,
> Mikko
>