USB: hub.c loops forever on resume from ram due to bluetooth

Okay, found it.  The root cause here was a missing CONFIG_USB_SUSPEND=y,
which means the hci_usb device never got marked as USB_STATE_SUSPENDED,
which then caused the loop to go on forever.

The system works fine now with CONFIG_USB_SUSPEND=y in the .config.

Here's the patch to prevent future lockups for this or other causes.
I no longer need it, but it does still seem a good idea.
Signed-off-by: NMark Lord <mlord@pobox.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/hub.c

@@ -403,9 +403,10 @@ static void hub_tt_kevent (struct work_struct *work)
 	struct usb_hub		*hub =
 		container_of(work, struct usb_hub, tt.kevent);
 	unsigned long		flags;
+	int			limit = 100;
 
 	spin_lock_irqsave (&hub->tt.lock, flags);
-	while (!list_empty (&hub->tt.clear_list)) {
+	while (--limit && !list_empty (&hub->tt.clear_list)) {
 		struct list_head	*temp;
 		struct usb_tt_clear	*clear;
 		struct usb_device	*hdev = hub->hdev;