ll_temac: add error checking to DMA init path

Add error checking to DMA descriptor rings initialization code.
Signed-off-by: NDenis Kirjanov <dkirjanov@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ll_temac_main.c

@@ -202,14 +202,29 @@ static int temac_dma_bd_init(struct net_device *ndev)
 	int i;
 
 	lp->rx_skb = kzalloc(sizeof(*lp->rx_skb) * RX_BD_NUM, GFP_KERNEL);
+	if (!lp->rx_skb) {
+		dev_err(&ndev->dev,
+				"can't allocate memory for DMA RX buffer\n");
+		goto out;
+	}
 	/* allocate the tx and rx ring buffer descriptors. */
 	/* returns a virtual addres and a physical address. */
 	lp->tx_bd_v = dma_alloc_coherent(ndev->dev.parent,
 					 sizeof(*lp->tx_bd_v) * TX_BD_NUM,
 					 &lp->tx_bd_p, GFP_KERNEL);
+	if (!lp->tx_bd_v) {
+		dev_err(&ndev->dev,
+				"unable to allocate DMA TX buffer descriptors");
+		goto out;
+	}
 	lp->rx_bd_v = dma_alloc_coherent(ndev->dev.parent,
 					 sizeof(*lp->rx_bd_v) * RX_BD_NUM,
 					 &lp->rx_bd_p, GFP_KERNEL);
+	if (!lp->rx_bd_v) {
+		dev_err(&ndev->dev,
+				"unable to allocate DMA RX buffer descriptors");
+		goto out;
+	}
 
 	memset(lp->tx_bd_v, 0, sizeof(*lp->tx_bd_v) * TX_BD_NUM);
 	for (i = 0; i < TX_BD_NUM; i++) {
@@ -227,7 +242,7 @@ static int temac_dma_bd_init(struct net_device *ndev)
 
 		if (skb == 0) {
 			dev_err(&ndev->dev, "alloc_skb error %d\n", i);
-			return -1;
+			goto out;
 		}
 		lp->rx_skb[i] = skb;
 		/* returns physical address of skb->data */
@@ -258,6 +273,9 @@ static int temac_dma_bd_init(struct net_device *ndev)
 	lp->dma_out(lp, TX_CURDESC_PTR, lp->tx_bd_p);
 
 	return 0;
+
+out:
+	return -ENOMEM;
 }
 
 /* ---------------------------------------------------------------------
@@ -505,7 +523,10 @@ static void temac_device_reset(struct net_device *ndev)
 	}
 	lp->dma_out(lp, DMA_CONTROL_REG, DMA_TAIL_ENABLE);
 
-	temac_dma_bd_init(ndev);
+	if (temac_dma_bd_init(ndev)) {
+		dev_err(&ndev->dev,
+				"temac_device_reset descriptor allocation failed\n");
+	}
 
 	temac_indirect_out32(lp, XTE_RXC0_OFFSET, 0);
 	temac_indirect_out32(lp, XTE_RXC1_OFFSET, 0);