[Bluetooth] Add suspend/resume support to the HCI USB driver

This patch implements the suspend/resume methods for the HCI USB
driver by killing all outstanding URBs on suspend, and re-issuing
them on resume.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/hci_usb.c

@@ -1045,10 +1045,81 @@ static void hci_usb_disconnect(struct usb_interface *intf)
 	hci_free_dev(hdev);
 }
 
+static int hci_usb_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct hci_usb *husb = usb_get_intfdata(intf);
+	struct list_head killed;
+	unsigned long flags;
+	int i;
+
+	if (!husb || intf == husb->isoc_iface)
+		return 0;
+
+	hci_suspend_dev(husb->hdev);
+
+	INIT_LIST_HEAD(&killed);
+
+	for (i = 0; i < 4; i++) {
+		struct _urb_queue *q = &husb->pending_q[i];
+		struct _urb *_urb, *_tmp;
+
+		while ((_urb = _urb_dequeue(q))) {
+			/* reset queue since _urb_dequeue sets it to NULL */
+			_urb->queue = q;
+			usb_kill_urb(&_urb->urb);
+			list_add(&_urb->list, &killed);
+		}
+
+		spin_lock_irqsave(&q->lock, flags);
+
+		list_for_each_entry_safe(_urb, _tmp, &killed, list) {
+			list_move_tail(&_urb->list, &q->head);
+		}
+
+		spin_unlock_irqrestore(&q->lock, flags);
+	}
+
+	return 0;
+}
+
+static int hci_usb_resume(struct usb_interface *intf)
+{
+	struct hci_usb *husb = usb_get_intfdata(intf);
+	unsigned long flags;
+	int i, err = 0;
+
+	if (!husb || intf == husb->isoc_iface)
+		return 0;
+
+	for (i = 0; i < 4; i++) {
+		struct _urb_queue *q = &husb->pending_q[i];
+		struct _urb *_urb;
+
+		spin_lock_irqsave(&q->lock, flags);
+
+		list_for_each_entry(_urb, &q->head, list) {
+			err = usb_submit_urb(&_urb->urb, GFP_ATOMIC);
+			if (err)
+				break;
+		}
+
+		spin_unlock_irqrestore(&q->lock, flags);
+
+		if (err)
+			return -EIO;
+	}
+
+	hci_resume_dev(husb->hdev);
+
+	return 0;
+}
+
 static struct usb_driver hci_usb_driver = {
 	.name		= "hci_usb",
 	.probe		= hci_usb_probe,
 	.disconnect	= hci_usb_disconnect,
+	.suspend	= hci_usb_suspend,
+	.resume		= hci_usb_resume,
 	.id_table	= bluetooth_ids,
 };