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From: Rob Herring <robherring2@gmail.com>
To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Andreas Herrmann <andreas.herrmann@calxeda.com>,
	Lennert Buytenhek <buytenh@wantstofly.org>,
	Rob Herring <rob.herring@calxeda.com>
Subject: [PATCH 05/11] net: calxedaxgmac: update ring buffer tx_head after barriers
Date: Mon, 26 Aug 2013 17:45:20 -0500	[thread overview]
Message-ID: <1377557126-10716-5-git-send-email-robherring2@gmail.com> (raw)
In-Reply-To: <1377557126-10716-1-git-send-email-robherring2@gmail.com>

From: Rob Herring <rob.herring@calxeda.com>

Ensure that the descriptor writes are visible before the ring buffer head
is updated. Since writel is a barrier, we can simply update the head after
the writel.

Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
---
 drivers/net/ethernet/calxeda/xgmac.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index 64854ad..f630855 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -1121,9 +1121,10 @@ static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	wmb();
 	desc_set_tx_owner(first, desc_flags | TXDESC_FIRST_SEG);
 
+	writel(1, priv->base + XGMAC_DMA_TX_POLL);
+
 	priv->tx_head = dma_ring_incr(entry, DMA_TX_RING_SZ);
 
-	writel(1, priv->base + XGMAC_DMA_TX_POLL);
 	if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) <
 	    MAX_SKB_FRAGS)
 		netif_stop_queue(dev);
-- 
1.8.1.2

  parent reply	other threads:[~2013-08-26 22:45 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-26 22:45 [PATCH 01/11] net: calxedaxgmac: remove NETIF_F_FRAGLIST setting Rob Herring
2013-08-26 22:45 ` [PATCH 02/11] net: calxedaxgmac: read correct field in xgmac_desc_get_buf_len Rob Herring
2013-08-26 22:45 ` [PATCH 03/11] net: calxedaxgmac: fix race between xgmac_tx_complete and xgmac_tx_err Rob Herring
2013-08-26 22:45 ` [PATCH 04/11] net: calxedaxgmac: fix possible skb free before tx complete Rob Herring
2013-08-26 22:45 ` Rob Herring [this message]
2013-08-26 22:45 ` [PATCH 06/11] net: calxedaxgmac: fix race with tx queue stop/wake Rob Herring
2013-08-27 18:31   ` Ben Hutchings
2013-08-26 22:45 ` [PATCH 07/11] net: calxedaxgmac: enable interrupts after napi_enable Rob Herring
2013-08-26 22:45 ` [PATCH 08/11] net: calxedaxgmac: fix various errors in xgmac_set_rx_mode Rob Herring
2013-08-26 22:45 ` [PATCH 09/11] net: calxedaxgmac: remove some unused statistic counters Rob Herring
2013-08-26 22:45 ` [PATCH 10/11] net: calxedaxgmac: fix rx DMA mapping API size mismatches Rob Herring
2013-08-26 22:45 ` [PATCH 11/11] net: calxedaxgmac: fix xgmac_xmit DMA mapping error handling Rob Herring

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