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>
This commit is contained in:
Oliver Neukum 2008-08-25 22:40:25 +02:00 committed by Greg Kroah-Hartman
parent c0f082c536
commit 1987625226
2 changed files with 73 additions and 0 deletions

View File

@ -716,3 +716,73 @@ int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor,
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);

View File

@ -1469,6 +1469,9 @@ extern void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor);
extern void usb_unanchor_urb(struct urb *urb);
extern int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor,
unsigned int timeout);
extern struct urb *usb_get_from_anchor(struct usb_anchor *anchor);
extern void usb_scuttle_anchored_urbs(struct usb_anchor *anchor);
extern int usb_anchor_empty(struct usb_anchor *anchor);
/**
* usb_urb_dir_in - check if an URB describes an IN transfer