[PATCH 3.16 128/217] net: bcmgenet: fix dma api length mismatch

[Ben Hutchings]

3.16.35-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>

commit eee577232203842b4dcadb7ab477a298479633ed upstream.

When un-mapping skb->data in __bcmgenet_tx_reclaim(),
we must use the length that was used in original dma_map_single(),
instead of skb->len that might be bigger (includes the frags)

We simply can store skb_len into tx_cb_ptr->dma_len and use it
at unmap time.

Fixes: 1c1008c793fa ("net: bcmgenet: add main driver file")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Acked-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -905,7 +905,7 @@ static void __bcmgenet_tx_reclaim(struct
 			dev->stats.tx_bytes += tx_cb_ptr->skb->len;
 			dma_unmap_single(&dev->dev,
 					dma_unmap_addr(tx_cb_ptr, dma_addr),
-					tx_cb_ptr->skb->len,
+					dma_unmap_len(tx_cb_ptr, dma_len),
 					DMA_TO_DEVICE);
 			bcmgenet_free_cb(tx_cb_ptr);
 		} else if (dma_unmap_addr(tx_cb_ptr, dma_addr)) {
@@ -990,7 +990,7 @@ static int bcmgenet_xmit_single(struct n
 	}
 
 	dma_unmap_addr_set(tx_cb_ptr, dma_addr, mapping);
-	dma_unmap_len_set(tx_cb_ptr, dma_len, skb->len);
+	dma_unmap_len_set(tx_cb_ptr, dma_len, skb_len);
 	length_status = (skb_len << DMA_BUFLENGTH_SHIFT) | dma_desc_flags |
 			(priv->hw_params->qtag_mask << DMA_TX_QTAG_SHIFT) |
 			DMA_TX_APPEND_CRC;