[Intel-gfx] [PATCH 10/15] drm/i915: Avoid sleeping inside per-engine reset

[Michel Thierry]

On 28/03/18 14:52, Chris Wilson wrote:
> Quoting Michel Thierry (2018-03-28 22:47:55)
>> On 28/03/18 14:18, Chris Wilson wrote:
>>> @@ -2094,7 +2095,7 @@ int intel_gpu_reset(struct drm_i915_private *dev_priv, unsigned engine_mask)
>>>        int retry;
>>>        int ret;
>>>    
>>> -     might_sleep();
>>> +     might_sleep_if(engine_mask == ALL_ENGINES);
>>
>> I think this should also be checking for intel_has_reset_engine.
>>
>> If i915.reset is not 2, engine_mask can be != ALL_ENGINES and still be a
>> full device reset.
> 
> Can it?
> 
> i915_reset -> intel_gpu_reset(ALL_ENGINES);
> i915_reset_engine -> intel_gt_reset_engine -> intel_gpu_reset(BIT(engine->id));
> 
> Plus a couple of others poking at intel_gpu_reset(ALL_ENGINES);
> 
> Have I missed someone using intel_gpu_reset() directly?

No, you're right, I didn't see i915_reset was passing ALL_ENGINES.

And as you also noted, the only one passing something different than 
ALL_ENGINES mask is intel_gt_reset_engine.

> -Chris
> 

Reviewed-by: Michel Thierry <michel.thierry at intel.com>