mb/google/fizz: Enable mbox command for ISL VR c-state issue
There is a potential IMVP8 issue for KBL that affects Intersil VRs
Fizz 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:65499724
BRANCH=None
TEST=Build and boot Fizz
Change-Id: Iebfda02df88ea0d2aaf79e8449b95c0eb2165c6b
Signed-off-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-on: https://review.coreboot.org/22763
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/fizz/devicetree.cb b/src/mainboard/google/fizz/devicetree.cb
index 18031d6..db6c83f 100644
--- a/src/mainboard/google/fizz/devicetree.cb
+++ b/src/mainboard/google/fizz/devicetree.cb
@@ -86,6 +86,10 @@
register "PmTimerDisabled" = "1"
register "SendVrMbxCmd" = "1" # IMVP8 workaround
+ # 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"