This is a note to let you know that I've just added the patch titled
net: mv643xx_eth: reclaim TX skbs only when released by the HW
to the 3.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-mv643xx_eth-reclaim-tx-skbs-only-when-released-by-the-hw.patch
and it can be found in the queue-3.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Tue Nov 18 09:07:25 PST 2014
From: Karl Beldan <karl.beldan@xxxxxxxxxxxxxxxx>
Date: Wed, 5 Nov 2014 15:32:59 +0100
Subject: net: mv643xx_eth: reclaim TX skbs only when released by the HW
From: Karl Beldan <karl.beldan@xxxxxxxxxxxxxxxx>
[ Upstream commit 2c2a9cbd64387d6b70ac5db013e9bfe9412c7354 ]
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@xxxxxxxxx>
Reported-by: Julien D'Ascenzio <jdascenzio@xxxxxxxx>
Signed-off-by: Karl Beldan <karl.beldan@xxxxxxxxxxxxxxxx>
Cc: Ian Campbell <ijc@xxxxxxxxxxxxxx>
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Cc: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxxxxxxxxxx>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/marvell/mv643xx_eth.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
--- 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 *
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 *
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);
Patches currently in stable-queue which might be from karl.beldan@xxxxxxxxxxxxxxxx are
queue-3.17/net-mv643xx_eth-reclaim-tx-skbs-only-when-released-by-the-hw.patch
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