nuport-mac: check dma_map_single address return values

SVN-Revision: 33067

target/linux/mcs814x/files-3.3/drivers/net/ethernet/mcs8140/nuport_mac.c

@@ -256,6 +256,8 @@ static int nuport_mac_start_tx_dma(struct nuport_mac_priv *priv,
 
 	priv->tx_addr = dma_map_single(&priv->pdev->dev, skb->data,
 			skb->len, DMA_TO_DEVICE);
+	if (!priv->tx_addr)
+		return -ENOMEM;
 
 	/* enable enhanced mode */
 	nuport_mac_writel(TX_DMA_ENH_ENABLE, TX_DMA_ENH);
@@ -297,6 +299,8 @@ static int nuport_mac_start_rx_dma(struct nuport_mac_priv *priv,
 
 	priv->rx_addr = dma_map_single(&priv->pdev->dev, skb->data,
 				RX_ALLOC_SIZE, DMA_FROM_DEVICE);
+	if (!priv->rx_addr)
+		return -ENOMEM;
 
 	nuport_mac_writel(priv->rx_addr, RX_BUFFER_ADDR);
 	wmb();