(In reply to dwagner from comment #7)
> (In reply to Andrey Grodzovsky from comment #6)
> > So with Arch Linux kernel it happens only during S3 but with
> > amd-staging-drm-next it happens once you start X ?
> 
> Yes. I know it sounds strange, but it's currently 100% reproducible to me:
> 
> Booting linux-4.17.2-ARCH with amdgpu.vm_update_mode=0:
>  X11 starts fine, but system crashes after minutes of firefox browsing
> 
> Booting linux-4.17.2-ARCH with amdgpu.vm_update_mode=3:
>  X11 starts fine, system does not crash (for at least hours of use)
>  but crashes as above if resumed from S3 sleep
> 
> Booting linux compiled from amd-staging-drm-next, as of commit
> 527d6e839a0e52b744fd092453544e4f58977334 from yesterday, with
> amdgpu.vm_update_mode=0:
>  X11 starts fine, but system crashes after minutes of firefox browsing
> 
> Booting linux compiled from amd-staging-drm-next, as of commit
> 527d6e839a0e52b744fd092453544e4f58977334 from yesterday, with
> amdgpu.vm_update_mode=3:
>  X11 does not start, crashes immediately with the same above pasted kernel
> BUG message and backtrace
> 
> 
> So something with CPU-based vm_update_mode is broken, but in a different way
> than the SDMA-based method.
> 
> I will change the subject of this report to reflect that this crash is not
> necessarily S3-resume-related.

I am going to try and reproduce the crash with CPU update mode here, please
describe exactly what ASIC are you using ?