[PATCH 4.2.y-ckt 189/305] net: mvpp2: fix missing DMA region unmap in egress processing

From: Kamal Mostafa
Date: Fri Jan 15 2016 - 19:42:06 EST

4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know.


From: Marcin Wojtas <mw@xxxxxxxxxxxx>

commit e864b4c7b184bde36fa6a02bb3190983d2f796f9 upstream.

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

Signed-off-by: Marcin Wojtas <mw@xxxxxxxxxxxx>

Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375
network unit")

Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
drivers/net/ethernet/marvell/mvpp2.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/marvell/mvpp2.c
index d9884fd..95db519 100644
--- 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,


- if (!skb)
- continue;
dma_unmap_single(port->dev->dev.parent, buf_phys_addr,
skb_headlen(skb), DMA_TO_DEVICE);
+ if (!skb)
+ continue;