[Intel-gfx] [PATCH] drm/i915: Cancel reset-engine if we couldn't find an active request

[Michel Thierry]

On 17/05/17 13:52, Chris Wilson wrote:
> On Wed, May 17, 2017 at 01:41:34PM -0700, Michel Thierry wrote:
>> @@ -2827,21 +2829,35 @@ int i915_gem_reset_prepare_engine(struct intel_engine_cs *engine)
>>
>>  	if (engine_stalled(engine)) {
>>  		request = i915_gem_find_active_request(engine);
>> -		if (request && request->fence.error == -EIO)
>> -			err = -EIO; /* Previous reset failed! */
>> +
>> +		if (request) {
>> +			if (request->fence.error == -EIO)
>> +				return ERR_PTR(-EIO); /* Previous reset failed! */
>> +
>> +			if (i915_gem_request_completed(request))
>> +				return NULL; /* request completed, skip it */
>
> This check is pointless here. We are just a few cycles since it was
> known to be true. Both paths should be doing it just before the actual
> reset for symmetry.

As you said, in gem_reset_request, 'guilty' should check for 
i915_gem_request_completed instead of engine_stalled... but at that 
point it's too late to cancel the reset (intel_gpu_reset has already 
been called).