[Intel-gfx] [PATCH v2 2/2] drm/i915: Invalidate the guc ggtt TLB upon insertion

[Tvrtko Ursulin]

On 01/12/2016 10:26, Chris Wilson wrote:
> On Thu, Dec 01, 2016 at 10:06:25AM +0000, Tvrtko Ursulin wrote:
>>
>> On 01/12/2016 09:46, Chris Wilson wrote:
>>> Move the GuC invalidation of its ggtt TLB to where we perform the ggtt
>>> modification rather than proliferate it into all the callers of the
>>> insert (which may or may not in fact have to do the insertion).
>>>
>>> v2: Just do the guc invalidate unconditionally, (afaict) it has no impact
>>> without the guc loaded on gen8+
>>
>> Why do you find it tempting to do it unconditionally? I would rather
>> not touch it on gen8 at all and would also prefer the conditional
>> flush in gen9.
>
> Because if I add a conditional here, I end up wanting writing a new vfunc
> for invalidate (if I can coax the gmch / gen6 / guc usage into something
> consistent). And I'm lazy. :)

To make sure I fully understand - just because you would not like to see 
the conditional in gen8_ggtt_invalidate? So you would add 
gen8_ggtt_invalidate and gen9_ggtt_invalidate with a GuC flush?

I would have thought conditional is less bothersome than making the 
unused piece of the GPU (on gen8) do stuff.

Regards,

Tvrtko