mb/google/nissa: Disable the External 1.05v VR in S0
Disable the external 1.05v VR in S0 as a fix for the
Display flicker issue in ADL-N.
Please refer the Doc with ID 742988 for more details.
BUG=b:248249033, b:245970842
TEST=Verified that the display flicker issue is fixed.
Signed-off-by: V Sowmya <v.sowmya@intel.com>
Change-Id: Iaa53bfd99a550b2cffcdaee640ee3a429e93aef7
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67653
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Vidya Gopalakrishnan <vidya.gopalakrishnan@intel.com>
Reviewed-by: Reka Norman <rekanorman@chromium.org>
Reviewed-by: Kangheui Won <khwon@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/mainboard/google/brya/variants/nivviks/overridetree.cb b/src/mainboard/google/brya/variants/nivviks/overridetree.cb
index d93095c..f8c5ef4 100644
--- a/src/mainboard/google/brya/variants/nivviks/overridetree.cb
+++ b/src/mainboard/google/brya/variants/nivviks/overridetree.cb
@@ -42,7 +42,7 @@
# Configure external V1P05/Vnn/VnnSx Rails
register "ext_fivr_settings" = "{
.configure_ext_fivr = 1,
- .v1p05_enable_bitmap = FIVR_ENABLE_ALL_SX,
+ .v1p05_enable_bitmap = FIVR_ENABLE_ALL_SX & ~FIVR_ENABLE_S0,
.vnn_enable_bitmap = FIVR_ENABLE_ALL_SX,
.vnn_sx_enable_bitmap = FIVR_ENABLE_ALL_SX,
.v1p05_supported_voltage_bitmap = FIVR_VOLTAGE_NORMAL,