[coreboot-gerrit] [S] Change in coreboot[main]: mb/google/fatcat: Disable VR settings on Panther Lake H SoC

[Jérémy Compostella (Code Review)]

Attention is currently required from: Avi Uday, Jayvik Desai, Kapil Porwal, Pranava Y N, Subrata Banik.

Hello Avi Uday, Jayvik Desai, Kapil Porwal, Pranava Y N, Subrata Banik,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/87403?usp=email

to look at the new patch set (#2).

Change subject: mb/google/fatcat: Disable VR settings on Panther Lake H SoC
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mb/google/fatcat: Disable VR settings on Panther Lake H SoC

Introduce a new static function `disable_vr_settings_on_pantherlake_h()`
to disable Voltage Regulator (VR) settings when a Panther Lake H System
on Chip (SoC) is detected.

The existing VR configurations, introduced by commit d19dd192dbe3
("mb/google/fatcat: Add Panther Lake U Fast VMode Voltage Regulator
settings"), are optimized for Panther Lake U SoC, which can cause
performance issues on Panther Lake H boards under stress due to the
I_TRIP value being lower than what the device could actually use. By
disabling these settings, the Firmware Support Package (FSP) falls back
to default values for the SoC, which are more suitable.

TEST=Observe the "Disabling VR settings on PTL-H" log during a boot test
     on a Panther Lake H variant.

Change-Id: Ifc371212259fa724425158ad9ebadebd30c81705
Signed-off-by: Jeremy Compostella 
---
M src/mainboard/google/fatcat/romstage.c
1 file changed, 30 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/03/87403/2