Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754657AbaKYKyu (ORCPT ); Tue, 25 Nov 2014 05:54:50 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:59113 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754058AbaKYKn0 (ORCPT ); Tue, 25 Nov 2014 05:43:26 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Karl Beldan , Ian Campbell , Eric Dumazet , Ezequiel Garcia , Sebastian Hesselbarth , "David S. Miller" , Luis Henriques Subject: [PATCH 3.16.y-ckt 219/254] net: mv643xx_eth: reclaim TX skbs only when released by the HW Date: Tue, 25 Nov 2014 10:39:29 +0000 Message-Id: <1416912004-5928-220-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1416912004-5928-1-git-send-email-luis.henriques@canonical.com> References: <1416912004-5928-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Karl Beldan commit 2c2a9cbd64387d6b70ac5db013e9bfe9412c7354 upstream. ATM, txq_reclaim will dequeue and free an skb for each tx desc released by the hw that has TX_LAST_DESC set. However, in case of TSO, each hw desc embedding the last part of a segment has TX_LAST_DESC set, losing the one-to-one 'last skb frag'/'TX_LAST_DESC set' correspondance, which causes data corruption. Fix this by checking TX_ENABLE_INTERRUPT instead of TX_LAST_DESC, and warn when trying to dequeue from an empty txq (which can be symptomatic of releasing skbs prematurely). Fixes: 3ae8f4e0b98 ('net: mv643xx_eth: Implement software TSO') Reported-by: Slawomir Gajzner Reported-by: Julien D'Ascenzio Signed-off-by: Karl Beldan Cc: Ian Campbell Cc: Eric Dumazet Cc: Ezequiel Garcia Cc: Sebastian Hesselbarth Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- drivers/net/ethernet/marvell/mv643xx_eth.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/net/ethernet/marvell/mv643xx_eth.c b/drivers/net/ethernet/marvell/mv643xx_eth.c index b151a949f352..d44560d1d268 100644 --- a/drivers/net/ethernet/marvell/mv643xx_eth.c +++ b/drivers/net/ethernet/marvell/mv643xx_eth.c @@ -1047,7 +1047,6 @@ static int txq_reclaim(struct tx_queue *txq, int budget, int force) int tx_index; struct tx_desc *desc; u32 cmd_sts; - struct sk_buff *skb; tx_index = txq->tx_used_desc; desc = &txq->tx_desc_area[tx_index]; @@ -1066,19 +1065,22 @@ static int txq_reclaim(struct tx_queue *txq, int budget, int force) reclaimed++; txq->tx_desc_count--; - skb = NULL; - if (cmd_sts & TX_LAST_DESC) - skb = __skb_dequeue(&txq->tx_skb); + if (!IS_TSO_HEADER(txq, desc->buf_ptr)) + dma_unmap_single(mp->dev->dev.parent, desc->buf_ptr, + desc->byte_cnt, DMA_TO_DEVICE); + + if (cmd_sts & TX_ENABLE_INTERRUPT) { + struct sk_buff *skb = __skb_dequeue(&txq->tx_skb); + + if (!WARN_ON(!skb)) + dev_kfree_skb(skb); + } if (cmd_sts & ERROR_SUMMARY) { netdev_info(mp->dev, "tx error\n"); mp->dev->stats.tx_errors++; } - if (!IS_TSO_HEADER(txq, desc->buf_ptr)) - dma_unmap_single(mp->dev->dev.parent, desc->buf_ptr, - desc->byte_cnt, DMA_TO_DEVICE); - dev_kfree_skb(skb); } __netif_tx_unlock_bh(nq); -- 2.1.0 -- 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/