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bnx2x: fix DMA unmapping of TSO split BDs 

bnx2x triggers warnings with CONFIG_DMA_API_DEBUG=y:

  WARNING: CPU: 0 PID: 2253 at lib/dma-debug.c:887 check_unmap+0xf8/0x920()
  bnx2x 0000:28:00.0: DMA-API: device driver frees DMA memory with
  different size [device address=0x00000000da2b389e] [map size=1490 bytes]
  [unmap size=66 bytes]

The reason is that bnx2x splits a TSO BD into two BDs (headers + data)
using one DMA mapping for both, but it uses only the length of the first
BD when unmapping.

This patch fixes the bug by unmapping the whole length of the two BDs.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michal Schmidt 2014-01-09 14:36:27 +01:00 committed by David S. Miller
parent 07edd741c8
commit 95e92fd40c
1 changed files with 9 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
View File

@ -160,6 +160,7 @@ static u16 bnx2x_free_tx_pkt(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata,
struct sk_buff *skb = tx_buf->skb;
u16 bd_idx = TX_BD(tx_buf->first_bd), new_cons;
int nbd;
u16 split_bd_len = 0;
/* prefetch skb end pointer to speedup dev_kfree_skb() */
prefetch(&skb->end);
@ -167,10 +168,7 @@ static u16 bnx2x_free_tx_pkt(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata,
DP(NETIF_MSG_TX_DONE, "fp[%d]: pkt_idx %d buff @(%p)->skb %p\n",
txdata->txq_index, idx, tx_buf, skb);
/* unmap first bd */
tx_start_bd = &txdata->tx_desc_ring[bd_idx].start_bd;
dma_unmap_single(&bp->pdev->dev, BD_UNMAP_ADDR(tx_start_bd),
BD_UNMAP_LEN(tx_start_bd), DMA_TO_DEVICE);
nbd = le16_to_cpu(tx_start_bd->nbd) - 1;
#ifdef BNX2X_STOP_ON_ERROR
@ -188,12 +186,19 @@ static u16 bnx2x_free_tx_pkt(struct bnx2x *bp, struct bnx2x_fp_txdata *txdata,
--nbd;
bd_idx = TX_BD(NEXT_TX_IDX(bd_idx));
/* ...and the TSO split header bd since they have no mapping */
/* TSO headers+data bds share a common mapping. See bnx2x_tx_split() */
if (tx_buf->flags & BNX2X_TSO_SPLIT_BD) {
tx_data_bd = &txdata->tx_desc_ring[bd_idx].reg_bd;
split_bd_len = BD_UNMAP_LEN(tx_data_bd);
--nbd;
bd_idx = TX_BD(NEXT_TX_IDX(bd_idx));
}
/* unmap first bd */
dma_unmap_single(&bp->pdev->dev, BD_UNMAP_ADDR(tx_start_bd),
BD_UNMAP_LEN(tx_start_bd) + split_bd_len,
DMA_TO_DEVICE);
/* now free frags */
while (nbd > 0) {