USB: anchor API changes needed for btusb
This extends the anchor API as btusb needs for autosuspend.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index eebc070..175d528 100644
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -716,3 +716,73 @@
msecs_to_jiffies(timeout));
}
EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout);
+
+/**
+ * usb_get_from_anchor - get an anchor's oldest urb
+ * @anchor: the anchor whose urb you want
+ *
+ * this will take the oldest urb from an anchor,
+ * unanchor and return it
+ */
+struct urb *usb_get_from_anchor(struct usb_anchor *anchor)
+{
+ struct urb *victim;
+ unsigned long flags;
+
+ spin_lock_irqsave(&anchor->lock, flags);
+ if (!list_empty(&anchor->urb_list)) {
+ victim = list_entry(anchor->urb_list.next, struct urb,
+ anchor_list);
+ usb_get_urb(victim);
+ spin_unlock_irqrestore(&anchor->lock, flags);
+ usb_unanchor_urb(victim);
+ } else {
+ spin_unlock_irqrestore(&anchor->lock, flags);
+ victim = NULL;
+ }
+
+ return victim;
+}
+
+EXPORT_SYMBOL_GPL(usb_get_from_anchor);
+
+/**
+ * usb_scuttle_anchored_urbs - unanchor all an anchor's urbs
+ * @anchor: the anchor whose urbs you want to unanchor
+ *
+ * use this to get rid of all an anchor's urbs
+ */
+void usb_scuttle_anchored_urbs(struct usb_anchor *anchor)
+{
+ struct urb *victim;
+ unsigned long flags;
+
+ spin_lock_irqsave(&anchor->lock, flags);
+ while (!list_empty(&anchor->urb_list)) {
+ victim = list_entry(anchor->urb_list.prev, struct urb,
+ anchor_list);
+ usb_get_urb(victim);
+ spin_unlock_irqrestore(&anchor->lock, flags);
+ /* this may free the URB */
+ usb_unanchor_urb(victim);
+ usb_put_urb(victim);
+ spin_lock_irqsave(&anchor->lock, flags);
+ }
+ spin_unlock_irqrestore(&anchor->lock, flags);
+}
+
+EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs);
+
+/**
+ * usb_anchor_empty - is an anchor empty
+ * @anchor: the anchor you want to query
+ *
+ * returns 1 if the anchor has no urbs associated with it
+ */
+int usb_anchor_empty(struct usb_anchor *anchor)
+{
+ return list_empty(&anchor->urb_list);
+}
+
+EXPORT_SYMBOL_GPL(usb_anchor_empty);
+