Index: drivers/input/i8042prt/pnp.c
===================================================================
--- drivers/input/i8042prt/pnp.c	(revision 74227)
+++ drivers/input/i8042prt/pnp.c	(working copy)
@@ -303,7 +303,9 @@
         return Status;
     }
 
-    if (DirqlMax == PortDeviceExtension->KeyboardInterrupt.Dirql)
+/* Or do we want to revert to pre-r30000:
+   unconditional "PortDeviceExtension->HighestDIRQLInterrupt = DirqlMax;"? */
+    if (PortDeviceExtension->KeyboardInterrupt.Dirql > PortDeviceExtension->HighestDIRQLInterrupt->Irql)
         PortDeviceExtension->HighestDIRQLInterrupt = PortDeviceExtension->KeyboardInterrupt.Object;
     PortDeviceExtension->Flags |= KEYBOARD_INITIALIZED;
     return STATUS_SUCCESS;
@@ -350,26 +352,16 @@
     if (!NT_SUCCESS(Status))
     {
         WARN_(I8042PRT, "IoConnectInterrupt() failed with status 0x%08x\n", Status);
-        goto cleanup;
+        return Status;
     }
 
-    if (DirqlMax == PortDeviceExtension->MouseInterrupt.Dirql)
+/* Or do we want to revert to pre-r30000:
+   unconditional "PortDeviceExtension->HighestDIRQLInterrupt = DirqlMax;"? */
+    if (NULL != PortDeviceExtension->HighestDIRQLInterrupt && PortDeviceExtension->MouseInterrupt.Dirql > PortDeviceExtension->HighestDIRQLInterrupt->Irql)
         PortDeviceExtension->HighestDIRQLInterrupt = PortDeviceExtension->MouseInterrupt.Object;
-
     PortDeviceExtension->Flags |= MOUSE_INITIALIZED;
-    Status = STATUS_SUCCESS;
 
-cleanup:
-    if (!NT_SUCCESS(Status))
-    {
-        PortDeviceExtension->Flags &= ~MOUSE_INITIALIZED;
-        if (PortDeviceExtension->MouseInterrupt.Object)
-        {
-            IoDisconnectInterrupt(PortDeviceExtension->MouseInterrupt.Object);
-            PortDeviceExtension->HighestDIRQLInterrupt = PortDeviceExtension->KeyboardInterrupt.Object;
-        }
-    }
-    return Status;
+    return STATUS_SUCCESS; // return Status;
 }
 
 static NTSTATUS
@@ -386,6 +378,7 @@
     return STATUS_SUCCESS;
 }
 
+/* Nit: Would you accept s/DeviceExtension/PortDeviceExtension/g so we use same name everywhere (all files)? */
 static NTSTATUS
 StartProcedure(
     IN PPORT_DEVICE_EXTENSION DeviceExtension)
@@ -443,6 +436,9 @@
         }
     }
 
+// I assume this ASSERT would be true, hence unneeded, isn't it?
+    ASSERT(DeviceExtension->HighestDIRQLInterrupt == 0);
+
     /* Connect interrupts */
     if (DeviceExtension->Flags & KEYBOARD_PRESENT &&
         DeviceExtension->Flags & KEYBOARD_CONNECTED &&
@@ -471,22 +467,29 @@
         if (NT_SUCCESS(Status))
         {
             DeviceExtension->Flags |= MOUSE_INITIALIZED;
+
+/* Or do we actually want to reset even when uninitialized? (See r53911 and older.)
+   Then, instead of moving code here,
+   the 2 SpinLock lines would need "if (DeviceExtension->HighestDIRQLInterrupt)" and/or MOUSE_INITIALIZED... */
+            /* HACK: the mouse has already been reset in i8042DetectMouse. This second
+               reset prevents some touchpads/mice from working (Dell D531, D600).
+               See CORE-6901 */
+            if (!(i8042HwFlags & FL_INITHACK))
+            {
+                /* Start the mouse */
+                Irql = KeAcquireInterruptSpinLock(DeviceExtension->HighestDIRQLInterrupt);
+                i8042IsrWritePort(DeviceExtension, MOU_CMD_RESET, CTRL_WRITE_MOUSE);
+                KeReleaseInterruptSpinLock(DeviceExtension->HighestDIRQLInterrupt, Irql);
+            }
+            else
+            {
+                WARN_(I8042PRT, "Skip mouse reset, because FL_INITHACK hardware is detected.\n");
+            }
         }
         else
         {
             WARN_(I8042PRT, "i8042ConnectMouseInterrupt failed: %lx\n", Status);
         }
-
-        /* Start the mouse */
-        Irql = KeAcquireInterruptSpinLock(DeviceExtension->HighestDIRQLInterrupt);
-        /* HACK: the mouse has already been reset in i8042DetectMouse. This second
-           reset prevents some touchpads/mice from working (Dell D531, D600).
-           See CORE-6901 */
-        if (!(i8042HwFlags & FL_INITHACK))
-        {
-            i8042IsrWritePort(DeviceExtension, MOU_CMD_RESET, CTRL_WRITE_MOUSE);
-        }
-        KeReleaseInterruptSpinLock(DeviceExtension->HighestDIRQLInterrupt, Irql);
     }
 
     return Status;