From cd6a2ad1b2d3444e815fb9b1a6ec1c98e0403c23 Mon Sep 17 00:00:00 2001 From: Jeremy Compostella Date: Thu, 21 Jul 2022 14:08:08 -0700 Subject: [PATCH] soc/intel/alderlake: Set Energy Perf Bias appropriate default value MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Change-Id: I5784656903d4c58bedc5063ee3ef310a99711050 Reviewed-on: https://review.coreboot.org/c/coreboot/+/66059 Reviewed-by: Michał Żygowski Reviewed-by: Cliff Huang Tested-by: build bot (Jenkins) --- src/soc/intel/alderlake/cpu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/src/soc/intel/alderlake/cpu.c b/src/soc/intel/alderlake/cpu.c index 7308185be7..f9e8f6f2fa 100644 --- a/src/soc/intel/alderlake/cpu.c +++ b/src/soc/intel/alderlake/cpu.c @@ -129,8 +129,9 @@ void soc_core_init(struct device *cpu) /* Enable Direct Cache Access */ configure_dca_cap(); - /* Set energy policy */ - set_energy_perf_bias(ENERGY_POLICY_NORMAL); + /* Set energy policy. The "normal" EPB (6) is not suitable for Alder + * Lake or Raptor Lake CPUs, as this results in higher uncore power. */ + set_energy_perf_bias(7); const config_t *conf = config_of_soc(); /* Set energy-performance preference */