[PATCH v2] UefiCpuPkg/MpLib.c: Set AP state after X2APIC mode enabled

[Jeff Fan <jeff.fan@intel.com>]

After X2APIC mode is enabled, APs need to be set tp IDLE state, otherwise APs
cannot be waken up by MP PPI services.

https://bugzilla.tianocore.org/show_bug.cgi?id=505

Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
---
 UefiCpuPkg/Library/MpInitLib/MpLib.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c
index 03d6c2d..e502e36 100644
--- a/UefiCpuPkg/Library/MpInitLib/MpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c
@@ -434,6 +434,8 @@ CollectProcessorCount (
   IN CPU_MP_DATA         *CpuMpData
   )
 {
+  UINTN                  Index;
+
   //
   // Send 1st broadcast IPI to APs to wakeup APs
   //
@@ -465,6 +467,12 @@ CollectProcessorCount (
     // Enable x2APIC on BSP
     //
     SetApicMode (LOCAL_APIC_MODE_X2APIC);
+    //
+    // Set BSP/Aps state to IDLE
+    //
+    for (Index = 0; Index < CpuMpData->CpuCount; Index++) {
+      SetApState (&CpuMpData->CpuData[Index], CpuStateIdle);
+    }
   }
   DEBUG ((DEBUG_INFO, "APIC MODE is %d\n", GetApicMode ()));
   //
-- 
2.9.3.windows.2