diff options
| -rw-r--r-- | drivers/usb/wusbcore/wa-xfer.c | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/drivers/usb/wusbcore/wa-xfer.c b/drivers/usb/wusbcore/wa-xfer.c index 16968c8..f5c81af 100644 --- a/drivers/usb/wusbcore/wa-xfer.c +++ b/drivers/usb/wusbcore/wa-xfer.c @@ -928,7 +928,7 @@ static void wa_xfer_delayed_run(struct wa_rpipe *rpipe) spin_lock_irqsave(&rpipe->seg_lock, flags); while (atomic_read(&rpipe->segs_available) > 0 && !list_empty(&rpipe->seg_list)) { - seg = list_entry(rpipe->seg_list.next, struct wa_seg, + seg = list_first_entry(&(rpipe->seg_list), struct wa_seg, list_node); list_del(&seg->list_node); xfer = seg->xfer; @@ -1093,30 +1093,35 @@ error_xfer_submit: * * We need to be careful here, as dequeue() could be called in the * middle. That's why we do the whole thing under the - * wa->xfer_list_lock. If dequeue() jumps in, it first locks urb->lock + * wa->xfer_list_lock. If dequeue() jumps in, it first locks xfer->lock * and then checks the list -- so as we would be acquiring in inverse - * order, we just drop the lock once we have the xfer and reacquire it - * later. + * order, we move the delayed list to a separate list while locked and then + * submit them without the list lock held. */ void wa_urb_enqueue_run(struct work_struct *ws) { struct wahc *wa = container_of(ws, struct wahc, xfer_work); struct wa_xfer *xfer, *next; struct urb *urb; + LIST_HEAD(tmp_list); + /* Create a copy of the wa->xfer_delayed_list while holding the lock */ spin_lock_irq(&wa->xfer_list_lock); - list_for_each_entry_safe(xfer, next, &wa->xfer_delayed_list, - list_node) { + list_cut_position(&tmp_list, &wa->xfer_delayed_list, + wa->xfer_delayed_list.prev); + spin_unlock_irq(&wa->xfer_list_lock); + + /* + * enqueue from temp list without list lock held since wa_urb_enqueue_b + * can take xfer->lock as well as lock mutexes. + */ + list_for_each_entry_safe(xfer, next, &tmp_list, list_node) { list_del_init(&xfer->list_node); - spin_unlock_irq(&wa->xfer_list_lock); urb = xfer->urb; wa_urb_enqueue_b(xfer); usb_put_urb(urb); /* taken when queuing */ - - spin_lock_irq(&wa->xfer_list_lock); } - spin_unlock_irq(&wa->xfer_list_lock); } EXPORT_SYMBOL_GPL(wa_urb_enqueue_run); |