From 2c2a9cbd64387d6b70ac5db013e9bfe9412c7354 Mon Sep 17 00:00:00 2001 From: Karl Beldan Date: Wed, 5 Nov 2014 15:32:59 +0100 Subject: net: mv643xx_eth: reclaim TX skbs only when released by the HW 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 --- drivers/net/ethernet/marvell/mv643xx_eth.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'drivers/net/ethernet/marvell/mv643xx_eth.c') 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); -- cgit v1.2.3-55-g7522