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Message-Id: <1268153703-4186-2-git-send-email-sgruszka@redhat.com>
Date:	Tue,  9 Mar 2010 17:55:01 +0100
From:	Stanislaw Gruszka <sgruszka@...hat.com>
To:	netdev@...r.kernel.org
Cc:	Vladislav Zolotarov <vladz@...adcom.com>,
	Eilon Greenstein <eilong@...adcom.com>,
	Michael Chan <mchan@...adcom.com>,
	Stanislaw Gruszka <sgruszka@...hat.com>
Subject: [PATCH 2/4] bnx2x: remove not necessary compiler barrier

Access to fp->tx_bd_prod is protected by __netif_tx_lock, so we do not
need any barrier for that.

Update of fp->tx_bd_cons in bnx2x_tx_int() is not protected by lock, but
barrier() nor smb_mb() in bnx2x_tx_avail() not guarantee we will see
values that is written on other cpu. Ordering issues between
netif_tx_stop_queue(), netif_tx_queue_stopped(), fp->tx_bd_cons = bd_cons
and bnx2x_tx_avail() are already handled by smp_mb() in bnx2x_tx_int()
and bnx2x_start_xmit().

Signed-off-by: Stanislaw Gruszka <sgruszka@...hat.com>
---
 drivers/net/bnx2x_main.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/drivers/net/bnx2x_main.c b/drivers/net/bnx2x_main.c
index 9fc0f6a..ae62b67 100644
--- a/drivers/net/bnx2x_main.c
+++ b/drivers/net/bnx2x_main.c
@@ -893,7 +893,6 @@ static inline u16 bnx2x_tx_avail(struct bnx2x_fastpath *fp)
 	u16 prod;
 	u16 cons;
 
-	barrier(); /* Tell compiler that prod and cons can change */
 	prod = fp->tx_bd_prod;
 	cons = fp->tx_bd_cons;
 
-- 
1.6.2.5

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