--- xnu/xnu-201/iokit/Kernel/IOInterruptController.cpp
+++ xnu/xnu-517.7.7/iokit/Kernel/IOInterruptController.cpp
@@ -96,10 +96,10 @@
       originalNub = vector->nub;
       originalSource = vector->source;
       
-      // Save the dis/enable state for the original consumer's interrupt.
-      // Then disable the source
-      wasDisabledSoft = vector->interruptDisabledSoft;
-      disableInterrupt(originalNub, originalSource);
+      // Physically disable the interrupt, but mark it as being enables in the hardware.
+      // The interruptDisabledSoft now indicates the driver's request for enablement.
+      disableVectorHard(vectorNumber, vector);
+      vector->interruptDisabledHard = 0;
       
       // Initialize the new shared interrupt controller.
       error = vector->sharedController->initInterruptController(this,
@@ -125,7 +125,17 @@
       // put the original consumor's interrupt back to normal and
       // get rid of whats left of the shared controller.
       if (error != kIOReturnSuccess) {
+	// Save the driver's interrupt enablement state.
+	wasDisabledSoft = vector->interruptDisabledSoft;
+	
+	// Make the interrupt really hard disabled.
+	vector->interruptDisabledSoft = 1;
+	vector->interruptDisabledHard = 1;
+	
+	// Enable the original consumer's interrupt if needed.
+	if (!wasDisabledSoft) originalNub->enableInterrupt(originalSource);
         enableInterrupt(originalNub, originalSource);
+	
         vector->sharedController->release();
         vector->sharedController = 0;
         IOUnlock(vector->interruptLock);
@@ -138,6 +148,13 @@
       vector->source  = 0;
       vector->target  = vector->sharedController;
       vector->refCon  = 0;
+      
+      // Save the driver's interrupt enablement state.
+      wasDisabledSoft = vector->interruptDisabledSoft;
+      
+      // Make the interrupt really hard disabled.
+      vector->interruptDisabledSoft = 1;
+      vector->interruptDisabledHard = 1;
       
       // Enable the original consumer's interrupt if needed.
       if (!wasDisabledSoft) originalNub->enableInterrupt(originalSource);
@@ -399,7 +416,7 @@
   }
   
   // Allocate the memory for the vectors
-  numVectors = 8; // For now a constant number.
+  numVectors = 32; // For now a constant number.
   vectors = (IOInterruptVector *)IOMalloc(numVectors * sizeof(IOInterruptVector));
   if (vectors == NULL) {
     IOFree(_interruptSources, sizeof(IOInterruptSource));
@@ -556,23 +573,26 @@
   long              vectorNumber;
   IOInterruptVector *vector;
   OSData            *vectorData;
-  IOInterruptState  interruptState;;
-  
-  interruptSources = nub->_interruptSources;
-  vectorData = interruptSources[source].vectorData;
-  vectorNumber = *(long *)vectorData->getBytesNoCopy();
-  vector = &vectors[vectorNumber];
-  
-  if (vector->interruptDisabledSoft) {
-    interruptState = IOSimpleLockLockDisableInterrupt(controllerLock);
-    vector->interruptDisabledSoft = 0;
-    vectorsEnabled++;
+  IOInterruptState  interruptState;
+  
+  interruptSources = nub->_interruptSources;
+  vectorData = interruptSources[source].vectorData;
+  vectorNumber = *(long *)vectorData->getBytesNoCopy();
+  vector = &vectors[vectorNumber];
+  
+  interruptState = IOSimpleLockLockDisableInterrupt(controllerLock);
+  if (!vector->interruptDisabledSoft) {
     IOSimpleLockUnlockEnableInterrupt(controllerLock, interruptState);
-    
-    if (controllerDisabled && (vectorsEnabled == vectorsRegistered)) {
-      controllerDisabled = 0;
-      provider->enableInterrupt(0);
-    }
+    return kIOReturnSuccess;
+  }
+  
+  vector->interruptDisabledSoft = 0;
+  vectorsEnabled++;
+  IOSimpleLockUnlockEnableInterrupt(controllerLock, interruptState);
+  
+  if (controllerDisabled && (vectorsEnabled == vectorsRegistered)) {
+    controllerDisabled = 0;
+    provider->enableInterrupt(0);
   }
   
   return kIOReturnSuccess;
@@ -585,23 +605,23 @@
   long              vectorNumber;
   IOInterruptVector *vector;
   OSData            *vectorData;
-  IOInterruptState  interruptState;;
-  
-  interruptSources = nub->_interruptSources;
-  vectorData = interruptSources[source].vectorData;
-  vectorNumber = *(long *)vectorData->getBytesNoCopy();
-  vector = &vectors[vectorNumber];
-  
+  IOInterruptState  interruptState;
+  
+  interruptSources = nub->_interruptSources;
+  vectorData = interruptSources[source].vectorData;
+  vectorNumber = *(long *)vectorData->getBytesNoCopy();
+  vector = &vectors[vectorNumber];
+  
+  interruptState = IOSimpleLockLockDisableInterrupt(controllerLock); 
   if (!vector->interruptDisabledSoft) {
-    interruptState = IOSimpleLockLockDisableInterrupt(controllerLock); 
     vector->interruptDisabledSoft = 1;
 #if __ppc__
     sync();
     isync();
 #endif
     vectorsEnabled--;
-    IOSimpleLockUnlockEnableInterrupt(controllerLock, interruptState);
-  }
+  }
+  IOSimpleLockUnlockEnableInterrupt(controllerLock, interruptState);
   
   if (!getPlatform()->atInterruptLevel()) {
     while (vector->interruptActive);