Index: adb_bus.c
===================================================================
--- adb_bus.c	(revision 184438)
+++ adb_bus.c	(working copy)
@@ -44,6 +44,7 @@
 static int adb_bus_probe(device_t dev);
 static int adb_bus_attach(device_t dev);
 static int adb_bus_detach(device_t dev);
+static void adb_bus_enumerate(void *xdev);
 static void adb_probe_nomatch(device_t dev, device_t child);
 static int adb_print_child(device_t dev, device_t child);
 
@@ -88,6 +89,27 @@
 adb_bus_attach(device_t dev)
 {
 	struct adb_softc *sc = device_get_softc(dev);
+	sc->enum_hook.ich_func = adb_bus_enumerate;
+	sc->enum_hook.ich_arg = dev;
+
+	/*
+	 * We should wait until interrupts are enabled to try to probe
+	 * the bus. Enumerating the ADB involves receiving packets,
+	 * which works best with interrupts enabled.
+	 */
+	
+	if (config_intrhook_establish(&sc->enum_hook) != 0)
+		return (ENOMEM);
+
+	return (0);
+}
+	
+static void
+adb_bus_enumerate(void *xdev)
+{
+	device_t dev = (device_t)xdev;
+
+	struct adb_softc *sc = device_get_softc(dev);
 	uint8_t i, next_free;
 	uint16_t r3;
 
@@ -165,7 +187,9 @@
 		}
 	}
 
-	return (bus_generic_attach(dev));
+	bus_generic_attach(dev);
+
+	config_intrhook_disestablish(&sc->enum_hook);
 }
 
 static int adb_bus_detach(device_t dev)
Index: adbvar.h
===================================================================
--- adbvar.h	(revision 184438)
+++ adbvar.h	(working copy)
@@ -37,16 +37,15 @@
 
 struct adb_softc {
 	device_t	sc_dev;
-
 	device_t	parent;
 
+	struct intr_config_hook enum_hook;
 	struct mtx	sc_sync_mtx;
 	
 	volatile int 	sync_packet;
 	volatile int	packet_reply;
 
 	uint16_t	autopoll_mask;
-
 	uint8_t		syncreg[8];
 
 	device_t	children[16];