soc/intel/alderlake: Set Energy Perf Bias appropriate default value
commitcd6a2ad1b2d3444e815fb9b1a6ec1c98e0403c23
authorJeremy Compostella <jeremy.compostella@intel.com>
Thu, 21 Jul 2022 21:08:08 +0000 (21 14:08 -0700)
committerPaul Fagerburg <pfagerburg@chromium.org>
Thu, 28 Jul 2022 14:57:59 +0000 (28 14:57 +0000)
tree1b5d0397789bfef4363c84d28b2b75d3c2945a51
parent117770d32468e63df37aee1c041b5dc7cc1d56d2
soc/intel/alderlake: Set Energy Perf Bias appropriate default value

The current "normal" EPB (six) setting resulted in the desired out of
box power and performance for several CPU generations.

However, a power and performance analysis on Alder Lake and Raptor
Lake CPUs demonstrates that this value results in undesirable higher
uncore power and that seven is a more appropriate value.

Note: the Linux kernel "4ecc933b x86: intel_epb: Allow model specific
      normal EPB value" patch sets the EPB to 7 for Alder Lake.

BRANCH=firmware-brya-14505.B
BUG=b:239853069
TEST=verify that EPB is set by coreboot

Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Change-Id: I5784656903d4c58bedc5063ee3ef310a99711050
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66059
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Reviewed-by: Cliff Huang <cliff.huang@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
src/soc/intel/alderlake/cpu.c