diff --git a/bus/usb/usb.c b/bus/usb/usb.c
index 79a79e644..9a78f2c4a 100644
--- a/bus/usb/usb.c
+++ b/bus/usb/usb.c
@@ -24,6 +24,7 @@
 #include <grub/list.h>
 
 static grub_usb_controller_dev_t grub_usb_list;
+struct grub_usb_attach_desc *attach_hooks;
 
 void
 grub_usb_controller_dev_register (grub_usb_controller_dev_t usb)
@@ -224,6 +225,25 @@ grub_usb_device_initialize (grub_usb_device_t dev)
 	}
     }
 
+  /* XXX: Just check configuration 0 for now.  */
+  for (i = 0; i < dev->config[0].descconf->numif; i++)
+    {
+      struct grub_usb_desc_if *interf;
+      struct grub_usb_attach_desc *desc;
+
+      interf = dev->config[0].interf[i].descif;
+
+      grub_dprintf ("usb", "iterate: interf=%d, class=%d, subclass=%d, protocol=%d\n",
+		    i, interf->class, interf->subclass, interf->protocol);
+
+      if (dev->config[0].interf[i].attached)
+	continue;
+
+      for (desc = attach_hooks; desc; desc = desc->next)
+	if (interf->class == desc->class && desc->hook (dev, 0, i))
+	  dev->config[0].interf[i].attached = 1;
+    }
+
   return GRUB_USB_ERR_NONE;
 
  fail:
@@ -234,8 +254,6 @@ grub_usb_device_initialize (grub_usb_device_t dev)
   return err;
 }
 
-struct grub_usb_attach_desc *attach_hooks;
-
 void
 grub_usb_register_attach_hook_class (struct grub_usb_attach_desc *desc)
 {
diff --git a/bus/usb/usbhub.c b/bus/usb/usbhub.c
index 523abf93e..48e3ce592 100644
--- a/bus/usb/usbhub.c
+++ b/bus/usb/usbhub.c
@@ -21,10 +21,22 @@
 #include <grub/mm.h>
 #include <grub/usb.h>
 #include <grub/misc.h>
+#include <grub/time.h>
 
 /* USB Supports 127 devices, with device 0 as special case.  */
 static struct grub_usb_device *grub_usb_devs[128];
 
+struct grub_usb_hub
+{
+  struct grub_usb_hub *next;
+  grub_usb_controller_t controller;
+  int nports;
+  grub_usb_speed_t *speed;
+  grub_usb_device_t dev;
+};
+
+struct grub_usb_hub *hubs;
+
 /* Add a device that currently has device number 0 and resides on
    CONTROLLER, the Hub reported that the device speed is SPEED.  */
 static grub_usb_device_t
@@ -137,43 +149,98 @@ grub_usb_add_hub (grub_usb_device_t dev)
   return GRUB_ERR_NONE;
 }
 
+static void
+attach_root_port (grub_usb_controller_t controller, int portno,
+		  grub_usb_speed_t speed)
+{
+  grub_usb_device_t dev;
+  grub_err_t err;
+
+  /* Enable the port.  */
+  err = controller->dev->portstatus (controller, portno, 0);
+  if (err)
+    return;
+
+  /* Enable the port.  */
+  err = controller->dev->portstatus (controller, portno, 1);
+  if (err)
+    return;
+
+  /* Enable the port and create a device.  */
+  dev = grub_usb_hub_add_dev (controller, speed);
+  if (! dev)
+    return;
+
+  /* If the device is a Hub, scan it for more devices.  */
+  if (dev->descdev.class == 0x09)
+    grub_usb_add_hub (dev);
+}
+
 grub_usb_err_t
 grub_usb_root_hub (grub_usb_controller_t controller)
 {
-  grub_err_t err;
-  int ports;
   int i;
+  struct grub_usb_hub *hub;
+
+  hub = grub_malloc (sizeof (*hub));
+  if (!hub)
+    return GRUB_USB_ERR_INTERNAL;
+
+  hub->next = hubs;
+  hubs = hub;
+  hub->controller = grub_malloc (sizeof (*controller));
+  if (!hub->controller)
+    return GRUB_USB_ERR_INTERNAL;
+
+  grub_memcpy (hub->controller, controller, sizeof (*controller));
+  hub->dev = 0;
 
   /* Query the number of ports the root Hub has.  */
-  ports = controller->dev->hubports (controller);
-
-  for (i = 0; i < ports; i++)
+  hub->nports = controller->dev->hubports (controller);
+  hub->speed = grub_malloc (sizeof (hub->speed[0]) * hub->nports);
+  if (!hub->speed)
     {
-      grub_usb_speed_t speed = controller->dev->detect_dev (controller, i);
+      grub_free (hub);
+      return GRUB_USB_ERR_INTERNAL;
+    }
 
-      if (speed != GRUB_USB_SPEED_NONE)
-	{
-	  grub_usb_device_t dev;
+  for (i = 0; i < hub->nports; i++)
+    {
+      hub->speed[i] = controller->dev->detect_dev (hub->controller, i);
 
-	  /* Enable the port.  */
-	  err = controller->dev->portstatus (controller, i, 1);
-	  if (err)
-	    continue;
-
-	  /* Enable the port and create a device.  */
-	  dev = grub_usb_hub_add_dev (controller, speed);
-	  if (! dev)
-	    continue;
-
-	  /* If the device is a Hub, scan it for more devices.  */
-	  if (dev->descdev.class == 0x09)
-	    grub_usb_add_hub (dev);
-	}
+      if (hub->speed[i] != GRUB_USB_SPEED_NONE)
+	attach_root_port (hub->controller, i, hub->speed[i]);
     }
 
   return GRUB_USB_ERR_NONE;
 }
 
+void
+grub_usb_poll_devices (void)
+{
+  struct grub_usb_hub *hub;
+
+  for (hub = hubs; hub; hub = hub->next)
+    {
+      int i;
+      /* Do we have to recheck number of ports?  */
+      for (i = 0; i < hub->nports; i++)
+	{
+	  grub_usb_speed_t speed;
+
+	  speed = hub->controller->dev->detect_dev (hub->controller, i);
+
+	  if (speed == hub->speed[i])
+	    continue;
+
+	  if (hub->speed[i] == GRUB_USB_SPEED_NONE
+	      && speed != GRUB_USB_SPEED_NONE)
+	    attach_root_port (hub->controller, i, speed);
+	  hub->speed[i] = speed;
+	}
+    }
+}
+
 int
 grub_usb_iterate (int (*hook) (grub_usb_device_t dev))
 {
diff --git a/disk/usbms.c b/disk/usbms.c
index 84597aa01..5550ff770 100644
--- a/disk/usbms.c
+++ b/disk/usbms.c
@@ -209,6 +209,8 @@ grub_usbms_iterate (int (*hook) (const char *name, int luns))
 {
   unsigned i;
 
+  grub_usb_poll_devices ();
+
   for (i = 0; i < ARRAY_SIZE (grub_usbms_devices); i++)
     if (grub_usbms_devices[i])
       {
@@ -389,6 +391,9 @@ grub_usbms_open (const char *name, struct grub_scsi *scsi)
 		       "not a USB Mass Storage device");
 
   devnum = grub_strtoul (name + 3, NULL, 10);
+
+  grub_usb_poll_devices ();
+
   if (!grub_usbms_devices[devnum])
     return grub_error (GRUB_ERR_UNKNOWN_DEVICE,
 		       "not a USB Mass Storage device");
diff --git a/include/grub/usb.h b/include/grub/usb.h
index 239905623..7c9dba12a 100644
--- a/include/grub/usb.h
+++ b/include/grub/usb.h
@@ -227,4 +227,6 @@ struct grub_usb_attach_desc
 void grub_usb_register_attach_hook_class (struct grub_usb_attach_desc *desc);
 void grub_usb_unregister_attach_hook_class (struct grub_usb_attach_desc *desc);
 
+void grub_usb_poll_devices (void);
+
 #endif /* GRUB_USB_H */