X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fbluetooth%2Fhci_usb.h;h=8e659914523f76990e1e736201044771531b02eb;hb=8f55c1e51fbb03998708bdd97d5b6665ab92462d;hp=56cd3a92ceca8c94228ca1ae06579088632a45bb;hpb=1ff8392c32a2645d2665ca779ecb91bb29361c13;p=linux-2.6-omap-h63xx.git

diff --git a/drivers/bluetooth/hci_usb.h b/drivers/bluetooth/hci_usb.h
index 56cd3a92cec..8e659914523 100644
--- a/drivers/bluetooth/hci_usb.h
+++ b/drivers/bluetooth/hci_usb.h
@@ -60,11 +60,6 @@ struct _urb {
 	struct urb        urb;
 };
 
-static inline void _urb_free(struct _urb *_urb)
-{
-	kfree(_urb);
-}
-
 static inline void _urb_queue_init(struct _urb_queue *q)
 {
 	INIT_LIST_HEAD(&q->head);
@@ -75,7 +70,8 @@ static inline void _urb_queue_head(struct _urb_queue *q, struct _urb *_urb)
 {
 	unsigned long flags;
 	spin_lock_irqsave(&q->lock, flags);
-	list_add(&_urb->list, &q->head); _urb->queue = q;
+	/* _urb_unlink needs to know which spinlock to use, thus smp_mb(). */
+	_urb->queue = q; smp_mb(); list_add(&_urb->list, &q->head);
 	spin_unlock_irqrestore(&q->lock, flags);
 }
 
@@ -83,19 +79,23 @@ static inline void _urb_queue_tail(struct _urb_queue *q, struct _urb *_urb)
 {
 	unsigned long flags;
 	spin_lock_irqsave(&q->lock, flags);
-	list_add_tail(&_urb->list, &q->head); _urb->queue = q;
+	/* _urb_unlink needs to know which spinlock to use, thus smp_mb(). */
+	_urb->queue = q; smp_mb(); list_add_tail(&_urb->list, &q->head);
 	spin_unlock_irqrestore(&q->lock, flags);
 }
 
 static inline void _urb_unlink(struct _urb *_urb)
 {
-	struct _urb_queue *q = _urb->queue;
+	struct _urb_queue *q;
 	unsigned long flags;
-	if (q) {
-		spin_lock_irqsave(&q->lock, flags);
-		list_del(&_urb->list); _urb->queue = NULL;
-		spin_unlock_irqrestore(&q->lock, flags);
-	}
+
+	smp_mb();
+	q = _urb->queue;
+	/* If q is NULL, it will die at easy-to-debug NULL pointer dereference.
+	   No need to BUG(). */
+	spin_lock_irqsave(&q->lock, flags);
+	list_del(&_urb->list); _urb->queue = NULL;
+	spin_unlock_irqrestore(&q->lock, flags);
 }
 
 struct hci_usb {