-----Original Message-----
From: Kinney, Michael D <michael.d.kinney@...>
Sent: Friday, June 11, 2021 6:46 AM
To: devel@edk2.groups.io
Cc: Chiu, Chasel <chasel.chiu@...>; Chaganty, Rangasai V
<rangasai.v.chaganty@...>
Subject: [edk2-platforms][Patch 1/3] CoffeelakeSiliconPkg/BaseSmbusLib: Fix
SmBusSendByte value

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3450

Update SmBusSendByte() to write value to Command Register instead of Host
Data registers.

Cc: Chasel Chiu <chasel.chiu@...>
Cc: Sai Chaganty <rangasai.v.chaganty@...>
Signed-off-by: Michael D Kinney <michael.d.kinney@...>
---
.../Pch/Library/BaseSmbusLib/BaseSmbusLib.c | 24 +++++++++++++------
1 file changed, 17 insertions(+), 7 deletions(-)

diff --git
a/Silicon/Intel/CoffeelakeSiliconPkg/Pch/Library/BaseSmbusLib/BaseSmbusLib.c
b/Silicon/Intel/CoffeelakeSiliconPkg/Pch/Library/BaseSmbusLib/BaseSmbusLib.c
index 3d6386d433..dacf9d03b2 100644
---
a/Silicon/Intel/CoffeelakeSiliconPkg/Pch/Library/BaseSmbusLib/BaseSmbusLib.c
+++ b/Silicon/Intel/CoffeelakeSiliconPkg/Pch/Library/BaseSmbusLib/BaseSm
+++ busLib.c
@@ -203,14 +203,24 @@ InternalSmBusNonBlock (
AuxiliaryControl |= B_SMBUS_IO_AAC;
}
//
- // Set Host Commond Register.
+ // We do not need Data Register for SendByte Command
//
- IoWrite8 (IoPortBaseAddress + R_SMBUS_IO_HCMD, (UINT8)
SMBUS_LIB_COMMAND (SmBusAddress));
- //
- // Write value to Host Data 0 and Host Data 1 Registers.
- //
- IoWrite8 (IoPortBaseAddress + R_SMBUS_IO_HD0, (UINT8) Value);
- IoWrite8 (IoPortBaseAddress + R_SMBUS_IO_HD1, (UINT8) (Value >> 8));
+ if ((HostControl == V_SMBUS_IO_SMB_CMD_BYTE) && ((SmBusAddress &
BIT0) == B_SMBUS_IO_WRITE)) {
+ //
+ // Set Host Command Register.
+ //
+ IoWrite8 (IoPortBaseAddress + R_SMBUS_IO_HCMD, (UINT8)Value); }
+ else {
+ //
+ // Set Host Command Register.
+ //
+ IoWrite8 (IoPortBaseAddress + R_SMBUS_IO_HCMD, (UINT8)
SMBUS_LIB_COMMAND (SmBusAddress));
+ //
+ // Write value to Host Data 0 and Host Data 1 Registers.
+ //
+ IoWrite8 (IoPortBaseAddress + R_SMBUS_IO_HD0, (UINT8) Value);
+ IoWrite8 (IoPortBaseAddress + R_SMBUS_IO_HD1, (UINT8) (Value >>
+ 8)); }
//
// Set Auxiliary Control Regiester.
//
--
2.31.1.windows.1