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Date: Thu, 9 Oct 2014 18:06:35 -0700
From: Florian Fainelli <f.fainelli@...il.com>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, pgynther@...gle.com, jaedon.shin@...il.com,
Florian Fainelli <f.fainelli@...il.com>
Subject: [PATCH net 1/3] net: bcmgenet: fix off-by-one in incrementing read pointer
Commit b629be5c8399d7c423b92135eb43a86c924d1cbc ("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: b629be5c8399 ("net: bcmgenet: check harder for out of memory conditions")
Reported-by: Jaedon Shin <jaedon.shin@...il.com>
Signed-off-by: Florian Fainelli <f.fainelli@...il.com>
---
drivers/net/ethernet/broadcom/genet/bcmgenet.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index fff2634b6f34..f1bcebcbba80 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -1287,9 +1287,6 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
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
@@ -1332,6 +1329,9 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
__func__, p_index, priv->rx_c_index,
priv->rx_read_ptr, dma_length_status);
+ priv->rx_read_ptr++;
+ priv->rx_read_ptr &= (priv->num_rx_bds - 1);
+
if (unlikely(!(dma_flag & DMA_EOP) || !(dma_flag & DMA_SOP))) {
netif_err(priv, rx_status, dev,
"dropping fragmented packet!\n");
--
1.9.1
--
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