Commit 19876252 authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
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USB: anchor API changes needed for btusb 



This extends the anchor API as btusb needs for autosuspend.


Signed-off-by: default avatarOliver Neukum <oneukum@suse.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent c0f082c5

drivers/usb/core/urb.c

+70 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/usb.h

+3 −0
Original line number Diff line number Diff line
@@ -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