Comment # 6 on bug 1094780 from Takashi Iwai

Thanks, it shows the very same code path, so it's the same crash consistently.

FWIW, the situation is like below.

An error was seen before the Oops happened at suspending at the second time:
  nouveau 0000:01:00.0: DRM: suspending display...
  nouveau 0000:01:00.0: DRM: evicting buffers...
  nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
  nouveau 0000:01:00.0: fifo: PBDMA0: 00008000 [] ch 0 [003fe12000 DRM] subc 0
mthd 0000 data 00000000
  nouveau 0000:01:00.0: DRM: failed to idle channel 0 [DRM]

The driver returned back and tried to resume again:

  nouveau 0000:01:00.0: DRM: resuming display...
  nouveau 0000:01:00.0: invalid power transition (from state 4 to 3)

... and the power state change was inconsistent.

Now, suspending again, and failed with "channel 0" (but no fifo error message
at this time).  Resuming again, though, caused an Oops.

  nouveau 0000:01:00.0: DRM: suspending console...
  nouveau 0000:01:00.0: DRM: suspending display...
  nouveau 0000:01:00.0: DRM: evicting buffers...
  nouveau 0000:01:00.0: DRM: waiting for kernel channels to go idle...
  nouveau 0000:01:00.0: DRM: failed to idle channel 0 [DRM]
  nouveau 0000:01:00.0: DRM: resuming display...
  BUG: unable to handle kernel paging request at ffff8805393d8ffc
  IP: evo_wait+0x56/0x120 [nouveau]
  ....