From d83e24d9d562bf9697a3fb8b02736e09d5cdafb0 Mon Sep 17 00:00:00 2001 From: Ravi Sarawadi Date: Wed, 14 Oct 2020 16:30:38 -0700 Subject: [PATCH] soc/intel/tigerlake: Disable C1 C-state Demotion Disable C1 C-state auto demotion to decrease SoC power usage. When set, processor will conditionally demote C3/C6/C7 requests to C1 based on uncore auto-demote information. BUG=b:161215906 TEST=Measure and confirm SoC power usage reduction for key use cases eg 'Google Meets video call' Measured on instrumented boards for Volteer EVT and Delbin. Below measurements for Volteer: Google meets with 720p w/ auto-demotion w/o auto-demotion System Power 13.14W 9.4W SOC Power 7.9W 5.4W Signed-off-by: Ravi Sarawadi Signed-off-by: Shweta Malik Change-Id: I649cafbaf03917d76521aa5f76ec58d218e1a1b1 Reviewed-on: https://review.coreboot.org/c/coreboot/+/46438 Tested-by: build bot (Jenkins) Reviewed-by: Tim Wawrzynczak --- src/soc/intel/tigerlake/fsp_params.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/soc/intel/tigerlake/fsp_params.c b/src/soc/intel/tigerlake/fsp_params.c index 887241b5c2..3427a61792 100644 --- a/src/soc/intel/tigerlake/fsp_params.c +++ b/src/soc/intel/tigerlake/fsp_params.c @@ -365,6 +365,10 @@ void platform_fsp_silicon_init_params_cb(FSPS_UPD *supd) /* EnableMultiPhaseSiliconInit for running MultiPhaseSiInit */ params->EnableMultiPhaseSiliconInit = 1; + + /* Disable C1 C-state Demotion */ + params->C1StateAutoDemotion = 0; + mainboard_silicon_init_params(params); }