[PATCH] SecurityPkg: TPM must go to Idle state on CRB command completion.

["Rodrigo Gonzalez del Cueto" <rodrigo.gonzalez.del.cueto@intel.com>]

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@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
---
 SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c b/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
index f1f8091683..34e3874a5b 100644
--- a/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
+++ b/SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2Ptp.c
@@ -310,7 +310,7 @@ PtpCrbTpmCommand (
     // Command completed, but buffer is not enough
     //
     Status = EFI_BUFFER_TOO_SMALL;
-    goto GoReady_Exit;
+    goto GoIdle_Exit;
   }
   *SizeOut = TpmOutSize;
   //
@@ -328,16 +328,6 @@ PtpCrbTpmCommand (
     DEBUG ((EFI_D_VERBOSE, "\n"));
   );
 
-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.
-- 
2.31.1.windows.1