[Intel-gfx] "BUG: unable to handle kernel NULL pointer dereference at 0000000000000070" in [i915] reset_common_ring

[Bjørn Mork]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> Quoting Bjørn Mork (2017-10-19 11:24:57)
>> Hello,
>> 
>> I get these Oopses from time to time, but unfortunately(?) not often
>> enough to be anywhere near reproducible.  But they seem to be related to
>> whatever activites my laptop/X-server/driver/gpu/screen is doing while
>> I'm not present. The oops happens when I'm away for a while.  So I guess
>> it might be something related to screensaver and/or power saving
>> actions.
>> 
>> There is always a GPU HANG prior to the Oops, so these events are
>> probably related.  
>
> It is, but the oops implies that hw got lost along the way. You need a
> more recent kernel to avoid that trap,

OK.  Would it be possible to backport those fixes to linux-4.9.y as a
service to Debian users and other stable kernel users? Or did you mean a
newer 4.9.y kernel?

> and at a guess
> intel_iommu=igfx_off to avoid the hangs in the first place.

Thanks for the tip. I'll try that


Bjørn