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authorOliver Neukum <oliver@neukum.org>2008-04-10 14:07:37 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2008-04-24 21:16:50 -0700
commiteda769593bbae8aee4e336b0732f6016353301a3 (patch)
tree04b5aae8d2cf133b86527b56505c26841b9f45f8 /drivers
parent9424ea29658ce5bcdcf527ddf9617b9507ddf1aa (diff)
USB: add extension of anchor API, usb_unlink_anchored_urbs
This adds the ability to trigger asynchronous unlinks of anchored URBs. This is needed for error handling in the comntext of completion handlers, which cannot sleep. Signed-off-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/core/urb.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index 9d7e63292c0..1d3ed1322fb 100644
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -590,6 +590,30 @@ void usb_kill_anchored_urbs(struct usb_anchor *anchor)
EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs);
/**
+ * usb_unlink_anchored_urbs - asynchronously cancel transfer requests en masse
+ * @anchor: anchor the requests are bound to
+ *
+ * this allows all outstanding URBs to be unlinked starting
+ * from the back of the queue. This function is asynchronous.
+ * The unlinking is just tiggered. It may happen after this
+ * function has returned.
+ */
+void usb_unlink_anchored_urbs(struct usb_anchor *anchor)
+{
+ struct urb *victim;
+
+ spin_lock_irq(&anchor->lock);
+ while (!list_empty(&anchor->urb_list)) {
+ victim = list_entry(anchor->urb_list.prev, struct urb,
+ anchor_list);
+ /* this will unanchor the URB */
+ usb_unlink_urb(victim);
+ }
+ spin_unlock_irq(&anchor->lock);
+}
+EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs);
+
+/**
* usb_wait_anchor_empty_timeout - wait for an anchor to be unused
* @anchor: the anchor you want to become unused
* @timeout: how long you are willing to wait in milliseconds