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net: bcmgenet: fix off-by-one in incrementing read pointer

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Commit b629be5c83 ("net: bcmgenet: check
harder for out of memory conditions") moved the increment of the local
read pointer *before* reading from the hardware descriptor using
dmadesc_get_length_status(), which creates an off-by-one situation.

Fix this by moving again the read_ptr increment after we have read the
hardware descriptor to get both the control block and the read pointer
back in sync.

Fixes: b629be5c83 ("net: bcmgenet: check harder for out of memory conditions")
Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Petri Gynther <pgynther@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Fainelli 2014-10-10 10:51:52 -07:00 committed by David S. Miller
parent 35b7a1915a
commit cf377d886f
1 changed files with 4 additions and 5 deletions
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9
drivers/net/ethernet/broadcom/genet/bcmgenet.c
View File

@ -1285,11 +1285,6 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
cb = &priv->rx_cbs[priv->rx_read_ptr];
skb = cb->skb;
rxpktprocessed++;
priv->rx_read_ptr++;
priv->rx_read_ptr &= (priv->num_rx_bds - 1);
/* We do not have a backing SKB, so we do not have a
* corresponding DMA mapping for this incoming packet since
* bcmgenet_rx_refill always either has both skb and mapping or
@ -1404,6 +1399,10 @@ refill:
err = bcmgenet_rx_refill(priv, cb);
if (err)
netif_err(priv, rx_err, dev, "Rx refill failed\n");
rxpktprocessed++;
priv->rx_read_ptr++;
priv->rx_read_ptr &= (priv->num_rx_bds - 1);
}
return rxpktprocessed;