From ca330c5a913a9b1690c709f4cfcd6be0c8696b14 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Mon, 22 Sep 2008 19:21:51 -0700 Subject: [PATCH] hci_usb: replace mb with smp_mb smp_mb is enough for ordering memory operations among processors,and mb is more expensive than smp_mb for UP machine, so replace it with smp_mb(). Signed-off-by: Ming Lei Acked-by: Marcel Holtmann Signed-off-by: Andrew Morton Signed-off-by: David S. Miller --- drivers/bluetooth/hci_usb.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/bluetooth/hci_usb.h b/drivers/bluetooth/hci_usb.h index 1790cc8e431..8e659914523 100644 --- a/drivers/bluetooth/hci_usb.h +++ b/drivers/bluetooth/hci_usb.h @@ -70,8 +70,8 @@ static inline void _urb_queue_head(struct _urb_queue *q, struct _urb *_urb) { unsigned long flags; spin_lock_irqsave(&q->lock, flags); - /* _urb_unlink needs to know which spinlock to use, thus mb(). */ - _urb->queue = q; mb(); list_add(&_urb->list, &q->head); + /* _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); } @@ -79,8 +79,8 @@ static inline void _urb_queue_tail(struct _urb_queue *q, struct _urb *_urb) { unsigned long flags; spin_lock_irqsave(&q->lock, flags); - /* _urb_unlink needs to know which spinlock to use, thus mb(). */ - _urb->queue = q; mb(); list_add_tail(&_urb->list, &q->head); + /* _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); } @@ -89,7 +89,7 @@ static inline void _urb_unlink(struct _urb *_urb) struct _urb_queue *q; unsigned long flags; - mb(); + smp_mb(); q = _urb->queue; /* If q is NULL, it will die at easy-to-debug NULL pointer dereference. No need to BUG(). */ -- 2.41.1