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authorKarl Beldan <karl.beldan@rivierawaves.com>2014-11-05 14:32:59 (GMT)
committerDavid S. Miller <davem@davemloft.net>2014-11-06 19:54:39 (GMT)
commit2c2a9cbd64387d6b70ac5db013e9bfe9412c7354 (patch)
tree24457fbbaab2016171b13aae6c2e105c082b8f2a
parent66f1c44887ba4f47d617f8ae21cf8e04e1892bd7 (diff)
downloadlinux-2c2a9cbd64387d6b70ac5db013e9bfe9412c7354.tar.xz
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 <slawomir.gajzner@gmail.com> Reported-by: Julien D'Ascenzio <jdascenzio@yahoo.fr> Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com> Cc: Ian Campbell <ijc@hellion.org.uk> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/marvell/mv643xx_eth.c18
1 files changed, 10 insertions, 8 deletions
diff --git a/drivers/net/ethernet/marvell/mv643xx_eth.c b/drivers/net/ethernet/marvell/mv643xx_eth.c
index b151a94..d44560d 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);