Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752825Ab3HZWsZ (ORCPT ); Mon, 26 Aug 2013 18:48:25 -0400 Received: from mail-oa0-f47.google.com ([209.85.219.47]:42591 "EHLO mail-oa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752400Ab3HZWp4 (ORCPT ); Mon, 26 Aug 2013 18:45:56 -0400 From: Rob Herring To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Andreas Herrmann , Lennert Buytenhek , Rob Herring Subject: [PATCH 05/11] net: calxedaxgmac: update ring buffer tx_head after barriers Date: Mon, 26 Aug 2013 17:45:20 -0500 Message-Id: <1377557126-10716-5-git-send-email-robherring2@gmail.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1377557126-10716-1-git-send-email-robherring2@gmail.com> References: <1377557126-10716-1-git-send-email-robherring2@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1312 Lines: 36 From: Rob Herring 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 Signed-off-by: Rob Herring --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/