[Intel-gfx] [PATCH v5 2/9] drm/i915: Define an engine class enum for the uABI

[Lionel Landwerlin]

On 09/11/17 11:13, Chris Wilson wrote:
> Quoting Tvrtko Ursulin (2017-11-09 10:04:17)
>> On 09/11/2017 09:37, Chris Wilson wrote:
>>> Quoting Tvrtko Ursulin (2017-11-09 09:27:33)
>>>> On 09/11/2017 09:13, Lionel Landwerlin wrote:
>>>>> On 08/11/17 19:14, Chris Wilson wrote:
>>>>>> +/*
>>>>>> + * Different engines serve different roles, and there may be more
>>>>>> than one
>>>>>> + * engine serving each role. enum drm_i915_gem_engine_class provides a
>>>>>> + * classification of the role of the engine, which may be used when
>>>>>> requesting
>>>>>> + * operations to be performed on a certain subset of engines, or for
>>>>>> providing
>>>>>> + * information about that group.
>>>>>> + */
>>>>>> +enum drm_i915_gem_engine_class {
>>>>>> +    I915_ENGINE_CLASS_OTHER = 0,
>>>>>> +    I915_ENGINE_CLASS_RENDER = 1,
>>>>>> +    I915_ENGINE_CLASS_COPY = 2,
>>>>>> +    I915_ENGINE_CLASS_VIDEO = 3,
>>>>>> +    I915_ENGINE_CLASS_VIDEO_ENHANCE = 4,
>>>>>> +};
>>>>>> +
>>>>> I've tried to build a bit UI in GPUTop to show this.
>>>>> I'm a bit skeptical about the OTHER type because if this enum is meant
>>>>> to be extended, then why do we need an OTHER class? We should create new
>>>>> classes instead.
>>>> Good point, I agree that I cannot find a reason why we would have it in
>>>> the uAPI. I suspect I was just doing a copy-paste-transform of the
>>>> hardware definitions from i915_reg.h.
>>> Do we want to keep 0 as undefined? It can be both a nuisance and a
>>> blessing...
>> What can you imagine it would be useful for?
> I915_EXEC_DEFAULT is of I915_ENGINE_CLASS_OTHER.
> -Chris
>
But that's render, right?