Trouble with TTM patches w/nouveau in linux-next

[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