Index: sys/dev/usb/usb_hub.c
===================================================================
--- sys/dev/usb/usb_hub.c	(revision 349802)
+++ sys/dev/usb/usb_hub.c	(working copy)
@@ -2274,18 +2274,19 @@
 }
 
 /*------------------------------------------------------------------------*
- *	usb_needs_explore_all
+ *	usb_needs_explore_all_flags
  *
  * This function is called whenever a new driver is loaded and will
  * cause that all USB buses are re-explored.
  *------------------------------------------------------------------------*/
-void
-usb_needs_explore_all(void)
+static void
+usb_needs_explore_all_flags(int flags)
 {
 	struct usb_bus *bus;
 	devclass_t dc;
 	device_t dev;
 	int max;
+	int x;
 
 	DPRINTFN(3, "\n");
 
@@ -2297,9 +2298,9 @@
 	/*
 	 * Explore all USB buses in parallel.
 	 */
-	max = devclass_get_maxunit(dc);
-	while (max >= 0) {
-		dev = devclass_get_device(dc, max);
+	max = devclass_get_maxunit(dc) + 1;
+	for (x = 0; x < max; x++) {
+		dev = devclass_get_device(dc, x);
 		if (dev) {
 			bus = device_get_softc(dev);
 			if (bus) {
@@ -2306,10 +2307,17 @@
 				usb_needs_explore(bus, 1);
 			}
 		}
-		max--;
+		if (flags & 1)
+			pause("W", hz / max);
 	}
 }
 
+void
+usb_needs_explore_all(void)
+{
+	usb_needs_explore_all_flags(0);
+}
+
 /*------------------------------------------------------------------------*
  *	usb_needs_explore_init
  *
@@ -2324,7 +2332,7 @@
 	 * being called:
 	 */
 	if (cold == 0)
-		usb_needs_explore_all();
+		usb_needs_explore_all_flags(1);
 	else
 		DPRINTFN(-1, "Cold variable is still set!\n");
 }