net: mvpp2: fix missing DMA region unmap in egress processing

The Tx descriptor release code currently calls dma_unmap_single() and
dev_kfree_skb_any() if the descriptor is associated with a non-NULL skb.
This condition is true only for the last fragment of the packet.

Since every descriptor's buffer is DMA-mapped it has to be properly
unmapped.

Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375
network unit")

Cc: <stable@vger.kernel.org> # v3.18+
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/marvell/mvpp2.c
index d9884fd15b453e2486177d58b7fc40bcd5aaf7cc..95db519d99014a1ba7e2923f386bcb7e56ecde20 100644 (file)
--- a/drivers/net/ethernet/marvell/mvpp2.c
+++ b/drivers/net/ethernet/marvell/mvpp2.c
@@ -4401,11 +4401,10 @@ static void mvpp2_txq_bufs_free(struct mvpp2_port *port,
 
                mvpp2_txq_inc_get(txq_pcpu);
 
-               if (!skb)
-                       continue;
-
                dma_unmap_single(port->dev->dev.parent, buf_phys_addr,
                                 skb_headlen(skb), DMA_TO_DEVICE);
+               if (!skb)
+                       continue;
                dev_kfree_skb_any(skb);
        }
 }