Commit 1987625226a918cd20c334ffce5e2a224cba0718
Committed by
Greg Kroah-Hartman
Greg Kroah-Hartman
1 parent
c0f082c536
Exists in
master
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7 other branches
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>
Showing 2 changed files with 73 additions and 0 deletions Side-by-side Diff
drivers/usb/core/urb.c
| ... | ... | @@ -716,4 +716,73 @@ |
| 716 | 716 | msecs_to_jiffies(timeout)); |
| 717 | 717 | } |
| 718 | 718 | EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); |
| 719 | + | |
| 720 | +/** | |
| 721 | + * usb_get_from_anchor - get an anchor's oldest urb | |
| 722 | + * @anchor: the anchor whose urb you want | |
| 723 | + * | |
| 724 | + * this will take the oldest urb from an anchor, | |
| 725 | + * unanchor and return it | |
| 726 | + */ | |
| 727 | +struct urb *usb_get_from_anchor(struct usb_anchor *anchor) | |
| 728 | +{ | |
| 729 | + struct urb *victim; | |
| 730 | + unsigned long flags; | |
| 731 | + | |
| 732 | + spin_lock_irqsave(&anchor->lock, flags); | |
| 733 | + if (!list_empty(&anchor->urb_list)) { | |
| 734 | + victim = list_entry(anchor->urb_list.next, struct urb, | |
| 735 | + anchor_list); | |
| 736 | + usb_get_urb(victim); | |
| 737 | + spin_unlock_irqrestore(&anchor->lock, flags); | |
| 738 | + usb_unanchor_urb(victim); | |
| 739 | + } else { | |
| 740 | + spin_unlock_irqrestore(&anchor->lock, flags); | |
| 741 | + victim = NULL; | |
| 742 | + } | |
| 743 | + | |
| 744 | + return victim; | |
| 745 | +} | |
| 746 | + | |
| 747 | +EXPORT_SYMBOL_GPL(usb_get_from_anchor); | |
| 748 | + | |
| 749 | +/** | |
| 750 | + * usb_scuttle_anchored_urbs - unanchor all an anchor's urbs | |
| 751 | + * @anchor: the anchor whose urbs you want to unanchor | |
| 752 | + * | |
| 753 | + * use this to get rid of all an anchor's urbs | |
| 754 | + */ | |
| 755 | +void usb_scuttle_anchored_urbs(struct usb_anchor *anchor) | |
| 756 | +{ | |
| 757 | + struct urb *victim; | |
| 758 | + unsigned long flags; | |
| 759 | + | |
| 760 | + spin_lock_irqsave(&anchor->lock, flags); | |
| 761 | + while (!list_empty(&anchor->urb_list)) { | |
| 762 | + victim = list_entry(anchor->urb_list.prev, struct urb, | |
| 763 | + anchor_list); | |
| 764 | + usb_get_urb(victim); | |
| 765 | + spin_unlock_irqrestore(&anchor->lock, flags); | |
| 766 | + /* this may free the URB */ | |
| 767 | + usb_unanchor_urb(victim); | |
| 768 | + usb_put_urb(victim); | |
| 769 | + spin_lock_irqsave(&anchor->lock, flags); | |
| 770 | + } | |
| 771 | + spin_unlock_irqrestore(&anchor->lock, flags); | |
| 772 | +} | |
| 773 | + | |
| 774 | +EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs); | |
| 775 | + | |
| 776 | +/** | |
| 777 | + * usb_anchor_empty - is an anchor empty | |
| 778 | + * @anchor: the anchor you want to query | |
| 779 | + * | |
| 780 | + * returns 1 if the anchor has no urbs associated with it | |
| 781 | + */ | |
| 782 | +int usb_anchor_empty(struct usb_anchor *anchor) | |
| 783 | +{ | |
| 784 | + return list_empty(&anchor->urb_list); | |
| 785 | +} | |
| 786 | + | |
| 787 | +EXPORT_SYMBOL_GPL(usb_anchor_empty); |
include/linux/usb.h
| ... | ... | @@ -1469,6 +1469,9 @@ |
| 1469 | 1469 | extern void usb_unanchor_urb(struct urb *urb); |
| 1470 | 1470 | extern int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, |
| 1471 | 1471 | unsigned int timeout); |
| 1472 | +extern struct urb *usb_get_from_anchor(struct usb_anchor *anchor); | |
| 1473 | +extern void usb_scuttle_anchored_urbs(struct usb_anchor *anchor); | |
| 1474 | +extern int usb_anchor_empty(struct usb_anchor *anchor); | |
| 1472 | 1475 | |
| 1473 | 1476 | /** |
| 1474 | 1477 | * usb_urb_dir_in - check if an URB describes an IN transfer |