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

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

From: Simon Guinot <simon.gui...@sequanux.org>

[ Upstream commit daf158d0d544cec80b7b30deff8cfc59a6e17610 ]

This patch fixes a regression introduced by the commit a84e32894191
("net: mvneta: fix refilling for Rx DMA buffers"). Due to this commit
the newly allocated Rx buffers are DMA-unmapped in place of those passed
to the networking stack. Obviously, this causes data corruptions.

This patch fixes the issue by ensuring that the right Rx buffers are
DMA-unmapped.

Reported-by: Oren Laskin <o...@igneous.io>
Signed-off-by: Simon Guinot <simon.gui...@sequanux.org>
Fixes: a84e32894191 ("net: mvneta: fix refilling for Rx DMA buffers")
Cc: <sta...@vger.kernel.org> # v3.8+
Tested-by: Oren Laskin <o...@igneous.io>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/net/ethernet/marvell/mvneta.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -1479,6 +1479,7 @@ static int mvneta_rx(struct mvneta_port
                struct mvneta_rx_desc *rx_desc = mvneta_rxq_next_desc_get(rxq);
                struct sk_buff *skb;
                unsigned char *data;
+               dma_addr_t phys_addr;
                u32 rx_status;
                int rx_bytes, err;
 
@@ -1486,6 +1487,7 @@ static int mvneta_rx(struct mvneta_port
                rx_status = rx_desc->status;
                rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE);
                data = (unsigned char *)rx_desc->buf_cookie;
+               phys_addr = rx_desc->buf_phys_addr;
 
                if (!mvneta_rxq_desc_is_first_last(rx_status) ||
                    (rx_status & MVNETA_RXD_ERR_SUMMARY)) {
@@ -1534,7 +1536,7 @@ static int mvneta_rx(struct mvneta_port
                if (!skb)
                        goto err_drop_frame;
 
-               dma_unmap_single(dev->dev.parent, rx_desc->buf_phys_addr,
+               dma_unmap_single(dev->dev.parent, phys_addr,
                                 MVNETA_RX_BUF_SIZE(pp->pkt_size), 
DMA_FROM_DEVICE);
 
                rcvd_pkts++;


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