diff options
| author | Eric Dumazet <edumazet@google.com> | 2012-06-13 09:45:16 +0000 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-07-25 04:11:40 +0100 |
| commit | dcf42d8ca45ca2009ead5cfae84c1c0de0a0af72 (patch) | |
| tree | e394ade7bc29ed9f5f2fbddb07099d3f8d1d856a | |
| parent | caac50847fd87dcc587181e3af3bd0aebf49964e (diff) | |
| download | lwn-dcf42d8ca45ca2009ead5cfae84c1c0de0a0af72.tar.gz lwn-dcf42d8ca45ca2009ead5cfae84c1c0de0a0af72.zip | |
bnx2x: fix panic when TX ring is full
commit bc14786a100cc6a81cd060e8031ec481241b418c upstream.
There is a off by one error in the minimal number of BD in
bnx2x_start_xmit() and bnx2x_tx_int() before stopping/resuming tx queue.
A full size GSO packet, with data included in skb->head really needs
(MAX_SKB_FRAGS + 4) BDs, because of bnx2x_tx_split()
This error triggers if BQL is disabled and heavy TCP transmit traffic
occurs.
bnx2x_tx_split() definitely can be called, remove a wrong comment.
Reported-by: Tomas Hruby <thruby@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: Yaniv Rosner <yanivr@broadcom.com>
Cc: Merav Sicron <meravs@broadcom.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Robert Evans <evansr@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c index 27d6d6cb1b9b..2c1a5c01a2d0 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c @@ -220,7 +220,7 @@ int bnx2x_tx_int(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata) if ((netif_tx_queue_stopped(txq)) && (bp->state == BNX2X_STATE_OPEN) && - (bnx2x_tx_avail(bp, txdata) >= MAX_SKB_FRAGS + 3)) + (bnx2x_tx_avail(bp, txdata) >= MAX_SKB_FRAGS + 4)) netif_tx_wake_queue(txq); __netif_tx_unlock(txq); @@ -2254,8 +2254,6 @@ int bnx2x_poll(struct napi_struct *napi, int budget) /* we split the first BD into headers and data BDs * to ease the pain of our fellow microcode engineers * we use one mapping for both BDs - * So far this has only been observed to happen - * in Other Operating Systems(TM) */ static noinline u16 bnx2x_tx_split(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata, @@ -2906,7 +2904,7 @@ netdev_tx_t bnx2x_start_xmit(struct sk_buff *skb, struct net_device *dev) txdata->tx_bd_prod += nbd; - if (unlikely(bnx2x_tx_avail(bp, txdata) < MAX_SKB_FRAGS + 3)) { + if (unlikely(bnx2x_tx_avail(bp, txdata) < MAX_SKB_FRAGS + 4)) { netif_tx_stop_queue(txq); /* paired memory barrier is in bnx2x_tx_int(), we have to keep @@ -2915,7 +2913,7 @@ netdev_tx_t bnx2x_start_xmit(struct sk_buff *skb, struct net_device *dev) smp_mb(); fp->eth_q_stats.driver_xoff++; - if (bnx2x_tx_avail(bp, txdata) >= MAX_SKB_FRAGS + 3) + if (bnx2x_tx_avail(bp, txdata) >= MAX_SKB_FRAGS + 4) netif_tx_wake_queue(txq); } txdata->tx_pkt++; |