(In reply to Mikael T from comment #17)
> still there with 4.13.0-37 ubuntu on HP Spectre, Core i7 7500U, intel HD
> Graphics 620, GM108M (GeForce 940MX) :
> 
> nouveau 0000:01:00.0: NVIDIA GM108 (1180d0a2)
> nouveau 0000:01:00.0: bios: version 82.08.62.00.15
> nouveau 0000:01:00.0: fb: 2048 MiB GDDR5
> nouveau 0000:01:00.0: bus: MMIO read of 00000000 FAULT at 612004 [ IBUS ]
> nouveau 0000:01:00.0: bus: MMIO read of 00000000 FAULT at 10ac08 [ IBUS ]

Those are differents errors.
You should open a new bug report for the first one.
The second one is https://bugs.freedesktop.org/show_bug.cgi?id=104835.