[Intel-gfx] [PATCH] drm/i915/selftests: Verify whitelist of context registers

[Tvrtko Ursulin]

On 24/04/2019 12:03, Chris Wilson wrote:
> Quoting Chris Wilson (2019-04-24 11:00:03)
>> Quoting Tvrtko Ursulin (2019-04-16 15:50:27)
>>>
>>> On 16/04/2019 10:12, Chris Wilson wrote:
>>>> +     rq = ERR_PTR(-ENODEV);
>>>> +     with_intel_runtime_pm(engine->i915, wakeref)
>>>> +             rq = i915_request_alloc(engine, ctx);
>>>> +     if (IS_ERR(rq))
>>>> +             goto err_unpin;
>>>> +
>>>> +     if (engine->emit_init_breadcrumb) { /* Be nice if we hang */
>>>> +             err = engine->emit_init_breadcrumb(rq);
>>>> +             if (err)
>>>> +                     goto err_request;
>>>> +     }
>>>> +
>>>> +     err = engine->emit_bb_start(rq, batch->node.start, 0, 0);
>>>
>>> Why is batch needed here when everything else is happy to run from the ring?
>>
>> Because we are playing with HW registers, I want reset to work safely.
>> So long as we have init_breadcrumb, the payload scrubbing should work.
>> Ok.
> 
> No, I am an idiot. The batch is so that we emulate userspace with
> unprivileged execution

Okay, keep the r-b. :)

Regards,

Tvrtko