Change in coreboot[master]: mb/google/poppy/variants/nautilus: Change IA/GT/SA slow slew rate set...

[Chris Wang (Code Review)]

Hello Chris Wang,

I'd like you to do a code review. Please visit

https://review.coreboot.org/22588

to review the following change.

Change subject: mb/google/poppy/variants/nautilus: Change IA/GT/SA slow slew rate settings
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mb/google/poppy/variants/nautilus: Change IA/GT/SA slow slew rate settings

Change IA/GT/SA slow slew rate settings.
System's audible noise will be reduced with them.

- Slow slew rate for IA/GT/SA : fast/16
- Fast PKG C-state ramp for IA/GT/SA: disabled

BRANCH=master
BUG=b:66462881
TEST=compiled/verified

Change-Id: Ibf11aba7bafb3b02c510905d7d904507eee6394b
Signed-off-by: Chris Wang 
---
M src/mainboard/google/poppy/variants/nautilus/devicetree.cb
1 file changed, 8 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/88/22588/1

diff --git a/src/mainboard/google/poppy/variants/nautilus/devicetree.cb b/src/mainboard/google/poppy/variants/nautilus/devicetree.cb
index efaea3f..6ee7a52 100644
--- a/src/mainboard/google/poppy/variants/nautilus/devicetree.cb
+++ b/src/mainboard/google/poppy/variants/nautilus/devicetree.cb
@@ -70,6 +70,14 @@
    register "pirqg_routing" = "PCH_IRQ11"
    register "pirqh_routing" = "PCH_IRQ11"

+	# VR Slew rate setting for improving audible noise
+	register "AcousticNoiseMitigation" = "1"
+	register "FastPkgCRampDisableIa" = "1"
+	register "FastPkgCRampDisableGt" = "1"
+	register "FastPkgCRampDisableSa" = "1"
+	register "SlowSlewRateForIa" = "3"      # Fast/16
+	register "SlowSlewRateForGt" = "3"      # Fast/16
+	register "SlowSlewRateForSa" = "3"      # Fast/16
    # VR Settings Configuration for 4 Domains
    #+----------------+-------+-------+-------+-------+
    #| Domain/Setting |  SA   |  IA   | GTUS  |  GTS  |