From b7f602a9fc35016d75f5669d4d413188283d1596 Mon Sep 17 00:00:00 2001 From: Sukumar Ghorai Date: Wed, 4 Oct 2023 23:37:12 -0700 Subject: mb/google/{rex,ovis}: Disable package C-state auto demotion Package C-state auto demotion feature allows hardware to determine lower C-state as per platform policy. Since platform sets performance policy to balanced from hardware, auto demotion can be disabled without performance impact. Also, disabling this feature results soc to enter below PC8 state and additional power savings ~30mW in Local-Video-Playback scenario. BUG=b:303546334 TEST=Local build successfully & Boot to OS successfully - Also check platform enter PC8 state in local video playback - before this change: # iotools rdmsr 0 0xE2 -> 0x0000000060008008 - After # iotools rdmsr 0 0xE2 -> 0x0000000000008008 Change-Id: Ia4cf4a7cb6bd5eaae26197b55f9385c078960d7b Signed-off-by: Sukumar Ghorai Reviewed-on: https://review.coreboot.org/c/coreboot/+/78250 Reviewed-by: Subrata Banik Reviewed-by: Eric Lai Tested-by: build bot (Jenkins) Reviewed-by: Kapil Porwal --- src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb | 3 +++ src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb | 3 +++ 2 files changed, 6 insertions(+) (limited to 'src/mainboard/google/rex/variants/baseboard') diff --git a/src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb b/src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb index 6fc0dc029a..7d39ece8c0 100644 --- a/src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb +++ b/src/mainboard/google/rex/variants/baseboard/ovis/devicetree.cb @@ -36,6 +36,9 @@ chip soc/intel/meteorlake # Disable C1 C-state auto-demotion register "disable_c1_state_auto_demotion" = "1" + # Disable PKGC-state demotion + register "disable_package_c_state_demotion" = "1" + # Enable Energy Reporting register "pch_pm_energy_report_enable" = "1" diff --git a/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb b/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb index ec57ee7f46..5894fe637a 100644 --- a/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb +++ b/src/mainboard/google/rex/variants/baseboard/rex/devicetree.cb @@ -36,6 +36,9 @@ chip soc/intel/meteorlake # Disable C1 C-state auto-demotion register "disable_c1_state_auto_demotion" = "1" + # Disable PKGC-state demotion + register "disable_package_c_state_demotion" = "1" + # Enable Energy Reporting register "pch_pm_energy_report_enable" = "1" -- cgit v1.2.3