2 files changed, 6 insertions, 0 deletions
diff --git a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugAgent.c b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugAgent.c
index 3eca30497f..6c32586303 100644
--- a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugAgent.c
+++ b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugAgent.c
@@ -2535,6 +2535,7 @@ InterruptProcess (
         CurrentDebugTimerInitCount = GetApicTimerInitCount ();
         if (mDebugMpContext.DebugTimerInitCount != CurrentDebugTimerInitCount) {
           InitializeDebugTimer (NULL, FALSE);
+          SaveAndSetDebugTimerInterrupt (TRUE);
         }
       }
 
diff --git a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugTimer.c b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugTimer.c
index 25d6468588..4a6ccdb7da 100644
--- a/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugTimer.c
+++ b/SourceLevelDebugPkg/Library/DebugAgent/DebugAgentCommon/DebugTimer.c
@@ -46,6 +46,11 @@ InitializeDebugTimer (
                    );
 
   InitializeApicTimer (ApicTimerDivisor, InitialCount, TRUE, DEBUG_TIMER_VECTOR);
+  //
+  // Disable Debug Timer interrupt to avoid it is delivered before Debug Port
+  // is initialized
+  //
+  DisableApicTimerInterrupt ();
 
   if (DumpFlag) {
     DEBUG ((EFI_D_INFO, "Debug Timer: FSB Clock    = %d\n", PcdGet32(PcdFSBClock)));