stmmac: dwmac-loongson: fix missing of_node_put() while module exiting

The node returned by of_get_child_by_name() with refcount decremented,
of_node_put() needs be called when finish using it. So add it in the
error path in loongson_dwmac_probe() and in loongson_dwmac_remove().

Fixes: 2ae3411 ("stmmac: dwmac-loongson: fix invalid mdio_node")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: Yang Yingliang

drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c

@@ -75,20 +75,24 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
 		plat->mdio_bus_data = devm_kzalloc(&pdev->dev,
 						   sizeof(*plat->mdio_bus_data),
 						   GFP_KERNEL);
-		if (!plat->mdio_bus_data)
-			return -ENOMEM;
+		if (!plat->mdio_bus_data) {
+			ret = -ENOMEM;
+			goto err_put_node;
+		}
 		plat->mdio_bus_data->needs_reset = true;
 	}
 
 	plat->dma_cfg = devm_kzalloc(&pdev->dev, sizeof(*plat->dma_cfg), GFP_KERNEL);
-	if (!plat->dma_cfg)
-		return -ENOMEM;
+	if (!plat->dma_cfg) {
+		ret = -ENOMEM;
+		goto err_put_node;
+	}
 
 	/* Enable pci device */
 	ret = pci_enable_device(pdev);
 	if (ret) {
 		dev_err(&pdev->dev, "%s: ERROR: failed to enable device\n", __func__);
-		return ret;
+		goto err_put_node;
 	}
 
 	/* Get the base address of device */
@@ -152,13 +156,18 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
 	pci_disable_msi(pdev);
 err_disable_device:
 	pci_disable_device(pdev);
+err_put_node:
+	of_node_put(plat->mdio_node);
 	return ret;
 }
 
 static void loongson_dwmac_remove(struct pci_dev *pdev)
 {
+	struct net_device *ndev = dev_get_drvdata(&pdev->dev);
+	struct stmmac_priv *priv = netdev_priv(ndev);
 	int i;
 
+	of_node_put(priv->plat->mdio_node);
 	stmmac_dvr_remove(&pdev->dev);
 
 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {