ll_temac: fix DMA resources leak

V2: Check pointers before releasing resources.

Fix DMA resources leak.
Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org>
Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>

drivers/net/ll_temac_main.c

@@ -192,6 +192,35 @@ static int temac_dcr_setup(struct temac_local *lp, struct of_device *op,
 
 #endif
 
+/**
+ *  * temac_dma_bd_release - Release buffer descriptor rings
+ */
+static void temac_dma_bd_release(struct net_device *ndev)
+{
+	struct temac_local *lp = netdev_priv(ndev);
+	int i;
+
+	for (i = 0; i < RX_BD_NUM; i++) {
+		if (!lp->rx_skb[i])
+			break;
+		else {
+			dma_unmap_single(ndev->dev.parent, lp->rx_bd_v[i].phys,
+					XTE_MAX_JUMBO_FRAME_SIZE, DMA_FROM_DEVICE);
+			dev_kfree_skb(lp->rx_skb[i]);
+		}
+	}
+	if (lp->rx_bd_v)
+		dma_free_coherent(ndev->dev.parent,
+				sizeof(*lp->rx_bd_v) * RX_BD_NUM,
+				lp->rx_bd_v, lp->rx_bd_p);
+	if (lp->tx_bd_v)
+		dma_free_coherent(ndev->dev.parent,
+				sizeof(*lp->tx_bd_v) * TX_BD_NUM,
+				lp->tx_bd_v, lp->tx_bd_p);
+	if (lp->rx_skb)
+		kfree(lp->rx_skb);
+}
+
 /**
  * temac_dma_bd_init - Setup buffer descriptor rings
  */
@@ -275,6 +304,7 @@ static int temac_dma_bd_init(struct net_device *ndev)
 	return 0;
 
 out:
+	temac_dma_bd_release(ndev);
 	return -ENOMEM;
 }
 
@@ -858,6 +888,8 @@ static int temac_stop(struct net_device *ndev)
 		phy_disconnect(lp->phy_dev);
 	lp->phy_dev = NULL;
 
+	temac_dma_bd_release(ndev);
+
 	return 0;
 }