[Intel-gfx] [PATCH] Revert "drm/i915/icl: WaEnableFloatBlendOptimization"

[Mika Kuoppala]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> Quoting Mika Kuoppala (2018-07-30 13:06:36)
>> The register for 0xe420 is unable to hold any value, including
>> this bit. The documentation is also mixed between having a
>> register bit for toggle and having a state command setup
>> for it. Apparently the register toggle is deprecated.
>> 
>> Remove the register toggle as evidence shows it's futile.
>> 
>> The thing remaining is an apology and humble request for
>> Mesa folks to resurrect their state setup for this as they
>> were on right track from start.
>> 
>> This reverts commit 0bf059f3532bb39c52d917142206a8554fc2f1c5.
>> 
>> Fixes: 0bf059f3532b ("drm/i915/icl: WaEnableFloatBlendOptimization")
>> References: HSDES#1406393558
>> Cc: Oscar Mateo <oscar.mateo at intel.com>
>> Cc: Anuj Phogat <anuj.phogat at gmail.com>
>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>> Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
>> Signed-off-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
>
> Acked-by: Chris Wilson <chris at chris-wilson.co.uk>
>
> The test results do confirm the register is a red herring, but we need
> someone to confirm that we aren't just using the wrong register etc.

I will ask around. Thanks for ack. Pushed.
-Mika