mb/google/poppy/variants/nami: Enable mbox command for ISL VR c-state issue
There is a potential IMVP8 issue for KBL that affects Intersil VRs
Nami is using one of the affected parts. The fix is to use an updated
microcode and also send a mailbox box command from FSP.
BUG=b:112081534
BRANCH=None
TEST=Build and boot Nami
Verify that suspend/resume and consecutive reboots are working
Change-Id: I6ec18a4c3fae6a66cf8a95685d91a8ba51e2697c
Signed-off-by: Shelley Chen <shchen@google.com>
Reviewed-on: https://review.coreboot.org/27780
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
diff --git a/src/mainboard/google/poppy/variants/nami/devicetree.cb b/src/mainboard/google/poppy/variants/nami/devicetree.cb
index 3835573..d505099 100644
--- a/src/mainboard/google/poppy/variants/nami/devicetree.cb
+++ b/src/mainboard/google/poppy/variants/nami/devicetree.cb
@@ -58,6 +58,10 @@
register "PmTimerDisabled" = "1"
register "VmxEnable" = "1"
+ # Intersil VR c-state issue workaround
+ # send VR mailbox command for IA/GT/SA rails
+ register "IslVrCmd" = "2"
+
register "pirqa_routing" = "PCH_IRQ11"
register "pirqb_routing" = "PCH_IRQ10"
register "pirqc_routing" = "PCH_IRQ11"