commit 2087ac1fc6fd9bbb1f7e16889e984e0af0510b4b

Author: Neil Horman <nhorman@tuxdriver.com>

Date:   Thu Jun 13 15:25:45 2013 -0400

    tulip: Properly check dma mapping result

    Tulip throws an error when dma debugging is enabled, as it doesn't properly

    check dma mapping results with dma_mapping_error() durring tx ring refills.

    Easy fix, just add it in, and drop the frame if the mapping is bad

    Signed-off-by: Neil Horman <nhorman@tuxdriver.com>

    CC: Grant Grundler <grundler@parisc-linux.org>

    CC: "David S. Miller" <davem@davemloft.net>

diff --git a/drivers/net/ethernet/dec/tulip/interrupt.c b/drivers/net/ethernet/dec/tulip/interrupt.c

index 28a5e42..92306b3 100644

--- a/drivers/net/ethernet/dec/tulip/interrupt.c

+++ b/drivers/net/ethernet/dec/tulip/interrupt.c

@@ -76,6 +76,12 @@ int tulip_refill_rx(struct net_device *dev)

 			mapping = pci_map_single(tp->pdev, skb->data, PKT_BUF_SZ,

 						 PCI_DMA_FROMDEVICE);

+			if (dma_mapping_error(&tp->pdev->dev, mapping)) {

+				dev_kfree_skb(skb);

+				tp->rx_buffers[entry].skb = NULL;

+				break;

+			}

+

 			tp->rx_buffers[entry].mapping = mapping;

 			tp->rx_ring[entry].buffer1 = cpu_to_le32(mapping);