2 files changed, 17 insertions, 14 deletions
diff --git a/SourceLevelDebugPkg/Include/TransferProtocol.h b/SourceLevelDebugPkg/Include/TransferProtocol.h
index 53e9f7cf36..42add9164a 100644
--- a/SourceLevelDebugPkg/Include/TransferProtocol.h
+++ b/SourceLevelDebugPkg/Include/TransferProtocol.h
@@ -2,7 +2,7 @@
   Transfer protocol defintions used by debug agent and host. It is only
   intended to be used by Debug related module implementation.
 
-  Copyright (c) 2010 - 2013, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2010 - 2014, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
@@ -53,6 +53,8 @@ typedef struct {
 #define DEBUG_COMMAND_REQUEST      (0 << 7)
 #define DEBUG_COMMAND_RESPONSE     (1 << 7)
 
+#define IS_REQUEST(x)              (((x)->Command & DEBUG_COMMAND_RESPONSE) == 0)
+
 //
 // HOST initiated commands
 //
diff --git a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugAgent.c b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugAgent.c
index a22494f364..99878903b1 100644
--- a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugAgent.c
+++ b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugAgent.c
@@ -605,19 +605,20 @@ ReadRemainingBreakPacket (
     return EFI_CRC_ERROR;
   }
   Mailbox = GetMailboxPointer();
-  if (((DebugHeader->Command & DEBUG_COMMAND_RESPONSE) == 0) &&
-       (DebugHeader->SequenceNo == (UINT8) (Mailbox->HostSequenceNo + 1))) {
-    //
-    // Only updagte HostSequenceNo for new command packet
-    //
-    UpdateMailboxContent (Mailbox, DEBUG_MAILBOX_HOST_SEQUENCE_NO_INDEX, DebugHeader->SequenceNo);
-    return EFI_SUCCESS;
-  } else {
-    //
-    // If one old command or response packet received, skip it
-    //
-    return EFI_DEVICE_ERROR;
+  if (IS_REQUEST (DebugHeader)) {
+    if (DebugHeader->SequenceNo == (UINT8) (Mailbox->HostSequenceNo + 1)) {
+      //
+      // Only updagte HostSequenceNo for new command packet 
+      //
+      UpdateMailboxContent (Mailbox, DEBUG_MAILBOX_HOST_SEQUENCE_NO_INDEX, DebugHeader->SequenceNo);
+      return EFI_SUCCESS;
+    }
+    if (DebugHeader->SequenceNo == Mailbox->HostSequenceNo) {
+      return EFI_SUCCESS;
+    }
   }
+
+  return EFI_DEVICE_ERROR;
 }
 
 /**
@@ -1646,7 +1647,7 @@ CommandCommunication (
 
     DebugAgentMsgPrint (DEBUG_AGENT_INFO, "TARGET: Try to get command from HOST...\n");
     Status = ReceivePacket ((UINT8 *)DebugHeader, &BreakReceived, NULL, READ_PACKET_TIMEOUT, TRUE);
-    if (Status != RETURN_SUCCESS || (DebugHeader->Command & DEBUG_COMMAND_RESPONSE) != 0) {
+    if (Status != RETURN_SUCCESS || !IS_REQUEST (DebugHeader)) {
       DebugAgentMsgPrint (DEBUG_AGENT_WARNING, "TARGET: Get command[%x] sequenceno[%x] returned status is [%x] \n", DebugHeader->Command, DebugHeader->SequenceNo, Status);
       DebugAgentMsgPrint (DEBUG_AGENT_WARNING, "TARGET: Get command failed or it's response packet not expected! \n");
       ReleaseMpSpinLock (&mDebugMpContext.DebugPortSpinLock);