diff --git a/source/components/events/evxface.c b/source/components/events/evxface.c
index 26caed93a..fb995b295 100644
--- a/source/components/events/evxface.c
+++ b/source/components/events/evxface.c
@@ -1,7 +1,7 @@
 /******************************************************************************
  *
  * Module Name: evxface - External interfaces for ACPI events
- *              $Revision: 1.164 $
+ *              $Revision: 1.165 $
  *
  *****************************************************************************/
 
@@ -961,7 +961,7 @@ AcpiReleaseGlobalLock (
     ACPI_STATUS             Status;
 
 
-    if (Handle != AcpiGbl_GlobalLockHandle)
+    if (!Handle || (Handle != AcpiGbl_GlobalLockHandle))
     {
         return (AE_NOT_ACQUIRED);
     }
diff --git a/source/components/executer/exfield.c b/source/components/executer/exfield.c
index b3452f435..75dc4f948 100644
--- a/source/components/executer/exfield.c
+++ b/source/components/executer/exfield.c
@@ -1,7 +1,7 @@
 /******************************************************************************
  *
  * Module Name: exfield - ACPI AML (p-code) execution - field manipulation
- *              $Revision: 1.130 $
+ *              $Revision: 1.131 $
  *
  *****************************************************************************/
 
@@ -206,7 +206,7 @@ AcpiExReadDataFromField (
         Status = AcpiExAccessRegion (ObjDesc, 0,
                     ACPI_CAST_PTR (ACPI_INTEGER, BufferDesc->Buffer.Pointer),
                     ACPI_READ | (ObjDesc->Field.Attribute << 16));
-        AcpiExReleaseGlobalLock ();
+        AcpiExReleaseGlobalLock (ObjDesc->CommonField.FieldFlags);
         goto Exit;
     }
 
@@ -263,7 +263,7 @@ AcpiExReadDataFromField (
     /* Read from the field */
 
     Status = AcpiExExtractFromField (ObjDesc, Buffer, (UINT32) Length);
-    AcpiExReleaseGlobalLock ();
+    AcpiExReleaseGlobalLock (ObjDesc->CommonField.FieldFlags);
 
 
 Exit:
@@ -381,7 +381,7 @@ AcpiExWriteDataToField (
         Status = AcpiExAccessRegion (ObjDesc, 0,
                         (ACPI_INTEGER *) Buffer,
                         ACPI_WRITE | (ObjDesc->Field.Attribute << 16));
-        AcpiExReleaseGlobalLock ();
+        AcpiExReleaseGlobalLock (ObjDesc->CommonField.FieldFlags);
 
         *ResultDesc = BufferDesc;
         return_ACPI_STATUS (Status);
@@ -460,7 +460,7 @@ AcpiExWriteDataToField (
     /* Write to the field */
 
     Status = AcpiExInsertIntoField (ObjDesc, Buffer, Length);
-    AcpiExReleaseGlobalLock ();
+    AcpiExReleaseGlobalLock (ObjDesc->CommonField.FieldFlags);
 
     /* Free temporary buffer if we used one */
 
diff --git a/source/components/executer/exmutex.c b/source/components/executer/exmutex.c
index 52e5faa95..729b173a5 100644
--- a/source/components/executer/exmutex.c
+++ b/source/components/executer/exmutex.c
@@ -2,7 +2,7 @@
 /******************************************************************************
  *
  * Module Name: exmutex - ASL Mutex Acquire/Release functions
- *              $Revision: 1.39 $
+ *              $Revision: 1.40 $
  *
  *****************************************************************************/
 
@@ -250,6 +250,11 @@ AcpiExAcquireMutexObject (
     ACPI_FUNCTION_TRACE_PTR (ExAcquireMutexObject, ObjDesc);
 
 
+    if (!ObjDesc)
+    {
+        return_ACPI_STATUS (AE_BAD_PARAMETER);
+    }
+
     /* Support for multiple acquires by the owning thread */
 
     if (ObjDesc->Mutex.ThreadId == ThreadId)
@@ -396,6 +401,11 @@ AcpiExReleaseMutexObject (
     ACPI_FUNCTION_TRACE (ExReleaseMutexObject);
 
 
+    if (ObjDesc->Mutex.AcquisitionDepth == 0)
+    {
+        return (AE_NOT_ACQUIRED);
+    }
+
     /* Match multiple Acquires with multiple Releases */
 
     ObjDesc->Mutex.AcquisitionDepth--;
@@ -501,16 +511,20 @@ AcpiExReleaseMutex (
     if (ObjDesc->Mutex.SyncLevel > WalkState->Thread->CurrentSyncLevel)
     {
         ACPI_ERROR ((AE_INFO,
-            "Cannot release Mutex [%4.4s], incorrect SyncLevel",
-            AcpiUtGetNodeName (ObjDesc->Mutex.Node)));
+            "Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %d current %d",
+            AcpiUtGetNodeName (ObjDesc->Mutex.Node),
+            ObjDesc->Mutex.SyncLevel, WalkState->Thread->CurrentSyncLevel));
         return_ACPI_STATUS (AE_AML_MUTEX_ORDER);
     }
 
     Status = AcpiExReleaseMutexObject (ObjDesc);
 
-   /* Restore the original SyncLevel */
+    if (ObjDesc->Mutex.AcquisitionDepth == 0)
+    {
+        /* Restore the original SyncLevel */
 
-    WalkState->Thread->CurrentSyncLevel = ObjDesc->Mutex.OriginalSyncLevel;
+        WalkState->Thread->CurrentSyncLevel = ObjDesc->Mutex.OriginalSyncLevel;
+    }
     return_ACPI_STATUS (Status);
 }
 
diff --git a/source/components/executer/exutils.c b/source/components/executer/exutils.c
index 7a0593c19..510a3ad01 100644
--- a/source/components/executer/exutils.c
+++ b/source/components/executer/exutils.c
@@ -2,7 +2,7 @@
 /******************************************************************************
  *
  * Module Name: exutils - interpreter/scanner utilities
- *              $Revision: 1.128 $
+ *              $Revision: 1.129 $
  *
  *****************************************************************************/
 
@@ -390,7 +390,8 @@ AcpiExAcquireGlobalLock (
  *
  * FUNCTION:    AcpiExReleaseGlobalLock
  *
- * PARAMETERS:  None
+ * PARAMETERS:  FieldFlags            - Flags with Lock rule:
+ *                                      AlwaysLock or NeverLock
  *
  * RETURN:      None
  *
@@ -400,7 +401,7 @@ AcpiExAcquireGlobalLock (
 
 void
 AcpiExReleaseGlobalLock (
-    void)
+    UINT32                  FieldFlags)
 {
     ACPI_STATUS             Status;
 
@@ -408,6 +409,13 @@ AcpiExReleaseGlobalLock (
     ACPI_FUNCTION_TRACE (ExReleaseGlobalLock);
 
 
+    /* Only use the lock if the AlwaysLock bit is set */
+
+    if (!(FieldFlags & AML_FIELD_LOCK_RULE_MASK))
+    {
+        return_VOID;
+    }
+
     /* Release the global lock */
 
     Status = AcpiExReleaseMutexObject (AcpiGbl_GlobalLockMutex);
diff --git a/source/include/acinterp.h b/source/include/acinterp.h
index 64a429b83..367266c53 100644
--- a/source/include/acinterp.h
+++ b/source/include/acinterp.h
@@ -1,7 +1,7 @@
 /******************************************************************************
  *
  * Name: acinterp.h - Interpreter subcomponent prototypes and defines
- *       $Revision: 1.170 $
+ *       $Revision: 1.171 $
  *
  *****************************************************************************/
 
@@ -701,7 +701,7 @@ AcpiExAcquireGlobalLock (
 
 void
 AcpiExReleaseGlobalLock (
-    void);
+    UINT32                  Rule);
 
 void
 AcpiExEisaIdToString (