-----Original Message-----
From: Gonzalez Del Cueto, Rodrigo <rodrigo.gonzalez.del.cueto@...>
Sent: Friday, December 17, 2021 10:48 AM
To: devel@edk2.groups.io
Cc: Gonzalez Del Cueto, Rodrigo <rodrigo.gonzalez.del.cueto@...>;
Wang, Jian J <jian.j.wang@...>; Yao, Jiewen <jiewen.yao@...>
Subject: [PATCH] SecurityPkg: TPM must go to Idle state on CRB command
completion

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3463

In V2: Fixed patch format and uncrustify cleanup

In V1: To follow the TCG CRB protocol specification, on every CRB TPM
command completion the TPM should return to Idle state, regardless of
the CRB Idle Bypass capability reported by the TPM device.

See: TCG PC Client Device Driver Design Principles for TPM 2.0,
Version 1.0, Rev 0.27

Signed-off-by: Rodrigo Gonzalez del Cueto
<rodrigo.gonzalez.del.cueto@...>
Cc: Jian J Wang <jian.j.wang@...>
Cc: Jiewen Yao <jiewen.yao@...>
---
SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
b/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
index 40ab998004..1d99beaa10 100644
--- a/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
+++ b/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
@@ -1,7 +1,7 @@
/** @file
PTP (Platform TPM Profile) CRB (Command Response Buffer) interface used by
dTPM2.0 library.

-Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2015 - 2021, Intel Corporation. All rights reserved.<BR>
Copyright (c), Microsoft Corporation.
SPDX-License-Identifier: BSD-2-Clause-Patent

@@ -320,7 +320,7 @@ PtpCrbTpmCommand (
// Command completed, but buffer is not enough
//
Status = EFI_BUFFER_TOO_SMALL;
- goto GoReady_Exit;
+ goto GoIdle_Exit;
}

*SizeOut = TpmOutSize;
@@ -340,16 +340,6 @@ PtpCrbTpmCommand (
DEBUG ((DEBUG_VERBOSE, "\n"));
DEBUG_CODE_END ();

-GoReady_Exit:
- //
- // Goto Ready State if command is completed successfully and TPM support
IdleBypass
- // If not supported. flow down to GoIdle
- //
- if (GetCachedIdleByPass () == 1) {
- MmioWrite32 ((UINTN)&CrbReg->CrbControlRequest,
PTP_CRB_CONTROL_AREA_REQUEST_COMMAND_READY);
- return Status;
- }
-
//
// Do not wait for state transition for TIMEOUT_C
// This function will try to wait 2 TIMEOUT_C at the beginning in next call.
--
2.26.2.windows.1