--- xnu/xnu-3248.50.21/iokit/Kernel/IOPMPowerStateQueue.cpp
+++ xnu/xnu-792.21.3/iokit/Kernel/IOPMPowerStateQueue.cpp
@@ -27,16 +27,15 @@
  */
  
 #include "IOPMPowerStateQueue.h"
+#undef super
+#define super IOEventSource
+OSDefineMetaClassAndStructors(IOPMPowerStateQueue, IOEventSource);
 
-#define super IOEventSource
-OSDefineMetaClassAndStructors( IOPMPowerStateQueue, IOEventSource )
+IOPMPowerStateQueue *IOPMPowerStateQueue::PMPowerStateQueue(OSObject *inOwner)
+{
+    IOPMPowerStateQueue     *me = new IOPMPowerStateQueue;
 
-IOPMPowerStateQueue * IOPMPowerStateQueue::PMPowerStateQueue(
-    OSObject * inOwner, Action inAction )
-{
-    IOPMPowerStateQueue * me = new IOPMPowerStateQueue;
-
-    if (me && !me->init(inOwner, inAction))
+    if(me && !me->init(inOwner, 0) )
     {
         me->release();
         return NULL;
@@ -45,60 +44,61 @@
     return me;
 }
 
-bool IOPMPowerStateQueue::init( OSObject * inOwner, Action inAction )
+bool IOPMPowerStateQueue::init(OSObject *owner, Action action)
 {
-    if (!inAction || !(super::init(inOwner, inAction)))
-        return false;
+    if(!(super::init(owner, (IOEventSource::Action) action))) return false;
 
-    queue_init( &queueHead );
-
-    queueLock = IOLockAlloc();
-    if (!queueLock)
-        return false;
+    // Queue of powerstate changes
+    changes = NULL;
 
     return true;
 }
 
-bool IOPMPowerStateQueue::submitPowerEvent(
-     uint32_t eventType,
-     void *   arg0,
-     uint64_t arg1 )
+
+bool IOPMPowerStateQueue::unIdleOccurred(IOService *inTarget, unsigned long inState)
 {
-    PowerEventEntry * entry;
+    PowerChangeEntry             *new_one = NULL;
 
-    entry = IONew(PowerEventEntry, 1);
-    if (!entry)
-        return false;
-
-    entry->eventType = eventType;
-    entry->arg0 = arg0;
-    entry->arg1 = arg1;
-
-    IOLockLock(queueLock);
-    queue_enter(&queueHead, entry, PowerEventEntry *, chain);
-    IOLockUnlock(queueLock);
+    new_one = (PowerChangeEntry *)IOMalloc(sizeof(PowerChangeEntry));
+    if(!new_one) return false;
+    
+    new_one->actionType = IOPMPowerStateQueue::kUnIdle;
+    new_one->state = inState;
+    new_one->target = inTarget;
+    
+    // Change to queue
+    OSEnqueueAtomic((void **)&changes, (void *)new_one, 0);
+    
     signalWorkAvailable();
 
     return true;
 }
 
-bool IOPMPowerStateQueue::checkForWork( void )
+// checkForWork() is called in a gated context
+bool IOPMPowerStateQueue::checkForWork()
 {
-    IOPMPowerStateQueueAction queueAction = (IOPMPowerStateQueueAction) action;
-    PowerEventEntry * entry;
+    PowerChangeEntry            *theNode;
+    int                         theState;
+    IOService                   *theTarget;
+    UInt16                      theAction;
+    
+    // Dequeue and process the state change request
+    if((theNode = (PowerChangeEntry *)OSDequeueAtomic((void **)&changes, 0)))
+    {
+        theState = theNode->state;
+        theTarget = theNode->target;
+        theAction = theNode->actionType;
+        IOFree((void *)theNode, sizeof(PowerChangeEntry));
+        
+        switch (theAction)
+        {
+            case kUnIdle:
+                theTarget->command_received(theState, 0, 0, 0);
+                break;
+        }
+    }
 
-	IOLockLock(queueLock);
-	while (!queue_empty(&queueHead))
-	{
-		queue_remove_first(&queueHead, entry, PowerEventEntry *, chain);		
-		IOLockUnlock(queueLock);
-
-        (*queueAction)(owner, entry->eventType, entry->arg0, entry->arg1);        
-        IODelete(entry, PowerEventEntry, 1);
-
-        IOLockLock(queueLock);
-	}
-	IOLockUnlock(queueLock);
-
-    return false;
+    // Return true if there's more work to be done
+    if(changes) return true;
+    else return false;
 }