[Intel-gfx] [PATCH] drm/i915: Don't skip request retirement if the active list is empty

[Jani Nikula]

On Fri, 29 May 2015, Jani Nikula <jani.nikula at linux.intel.com> wrote:
> On Thu, 28 May 2015, Chris Wilson <chris at chris-wilson.co.uk> wrote:
>> On Thu, May 28, 2015 at 06:32:36PM +0300, ville.syrjala at linux.intel.com wrote:
>>> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>> 
>>> Apparently we can have requests even if though the active list is empty,
>>> so do the request retirement regardless of whether there's anything
>>> on the active list.
>>> 
>>> The way it happened here is that during suspend intel_ring_idle()
>>> notices the olr hanging around and then proceeds to get rid of it by
>>> adding a request. However since there was nothing on the active lists
>>> i915_gem_retire_requests() didn't clean those up, and so the idle work
>>> never runs, and we leave the GPU "busy" during suspend resulting in a
>>> WARN later.
>>
>> Whlist I agree (I use list_empty(&ring->request_list);) I strongly
>> suspect something (i.e. execlists) isn't managing the active_list
>> correctly. Pretty much the only thing that can generate a request
>> without an object (and so avoid touching the active_list) is a CS flip,
>> and I doubt you are using those...
>>
>> Anyway,
>> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
>> Cc: stable at vger.linux.org
>
> Pushed to drm-intel-fixes, thanks for the patch and review.

Reverted from drm-intel-fixes because I misapplied it, and applied to
drm-intel-next-fixes instead. Sorry for the noise.

BR,
Jani.



>
> BR,
> Jani.
>
>
>> -Chris
>>
>> -- 
>> Chris Wilson, Intel Open Source Technology Centre
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>> Intel-gfx at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> -- 
> Jani Nikula, Intel Open Source Technology Center

-- 
Jani Nikula, Intel Open Source Technology Center