Change in coreboot[master]: mb/google/zork: fine tune stamp_boost parameter for dirinboz

[Patrick Georgi (Code Review)]

Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/52312 )

Change subject: mb/google/zork: fine tune stamp_boost parameter for dirinboz
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mb/google/zork: fine tune stamp_boost parameter for dirinboz

The new discovery from Google & AMD, the value currently used
STAPM Time Constant of 1640 is reducing real PPT TSP from the
target 4.8W to 4.68W.

Furthermore, when using the "default" STAPM Time Constant of 1400,
the actual real PPT TSP becomes 4.89W.

Operating at this default settings therefore uses a higher real PPT TSP,
which results in a significant performance improvement.

BUG=b:175364713,b:184902568
BRANCH=zork
TEST=1. emerge-zork coreboot
     2. run balance performance and skin temperature test => pass

Signed-off-by: Kevin Chiu 
Change-Id: I9cf4d51f42fe250340bcb642db07796c9a480c34
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52312
Reviewed-by: Kangheui Won 
Reviewed-by: Sam McNally 
Tested-by: build bot (Jenkins) 
---
M src/mainboard/google/zork/variants/dirinboz/overridetree.cb
1 file changed, 1 insertion(+), 1 deletion(-)

Approvals:
  build bot (Jenkins): Verified
  Kangheui Won: Looks good to me, approved
  Sam McNally: Looks good to me, approved

diff --git a/src/mainboard/google/zork/variants/dirinboz/overridetree.cb b/src/mainboard/google/zork/variants/dirinboz/overridetree.cb
index 7139ac8..5675487 100644
--- a/src/mainboard/google/zork/variants/dirinboz/overridetree.cb
+++ b/src/mainboard/google/zork/variants/dirinboz/overridetree.cb
@@ -12,7 +12,7 @@
    register "slow_ppt_limit_mW" = "6000"
    register "fast_ppt_limit_mW" = "9000"
    register "slow_ppt_time_constant_s" = "5"
-	register "stapm_time_constant_s" = "1640"
+	register "stapm_time_constant_s" = "1400"
    register "sustained_power_limit_mW" = "4800"

register "telemetry_vddcr_vdd_slope_mA" = "41322"