[Intel-gfx] [PATCH v3] drm/i915: Enable WaProgramMgsrForCorrectSliceSpecificMmioReads for Gen9

[Chiou, Cooper]

> I was referring to the original performance regression report which came
> from LKP which was on "i7-7567U" so Kabylake. Can yo find such machine to
> test on?
[Chiou, Cooper] Yes, lkp-tests team has tested this patch on lkp-kbl-nuc1 (KBL i7-7567U) as the following mail thread and there is no performance regression per their confirmed.
From: Chen, Rong A <rong.a.chen at intel.com>
Sent: Thursday, March 4, 2021 9:56 PM
Hi Cooper,

There's no regression with this patch:

d912096c40cdc drm/i915: Enable
WaProgramMgsrForCorrectSliceSpecificMmioReads for Gen9
f69d02e37a856 Merge tag 'misc-5.12-2021-03-02' of git://git.kernel.dk/linux-block

f69d02e37a85645a  d912096c40cdc3bc9364966971  testcase/testparams/testbox
----------------  --------------------------  ---------------------------
          %stddev      change         %stddev
              \          |                \
      29.79                       29.67 
phoronix-test-suite/performance-true-Fullscreen-Ultimate-1-Gran_Paradiso_Island__Approxima-supertuxkart-1.5.2-ucode=0xde/lkp-kbl-nuc1
      29.79                       29.67        GEO-MEAN 
phoronix-test-suite.supertuxkart.1280x1024.Fullscreen.Ultimate.1.GranParadisoIsland.frames_per_second