[PATCH net v2] net: emaclite: Add error handling for of_address_ and _mdio_setup functions

[Radhey Shyam Pandey]

From: Shravya Kumbham <shravya.kumbham at xilinx.com>

Add ret variable, condition to check the return value and error
path for the of_address_to_resource() function. It also adds error
handling for mdio setup and decrement refcount of phy node.

Addresses-Coverity: Event check_return value.
Signed-off-by: Shravya Kumbham <shravya.kumbham at xilinx.com>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey at xilinx.com>
---
Changes for v2:

- Change subject_prefix to target net tree.
- Add error handling for mdio_setup and remove phy_read changes.
  Error checking of phy_read will be added along with phy_write
  in a followup patch. Document the changes in commit description.
---
 drivers/net/ethernet/xilinx/xilinx_emaclite.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/xilinx_emaclite.c b/drivers/net/ethernet/xilinx/xilinx_emaclite.c
index 0c26f5bcc523..4e0005164785 100644
--- a/drivers/net/ethernet/xilinx/xilinx_emaclite.c
+++ b/drivers/net/ethernet/xilinx/xilinx_emaclite.c
@@ -820,7 +820,7 @@ static int xemaclite_mdio_write(struct mii_bus *bus, int phy_id, int reg,
 static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
 {
 	struct mii_bus *bus;
-	int rc;
+	int rc, ret;
 	struct resource res;
 	struct device_node *np = of_get_parent(lp->phy_node);
 	struct device_node *npp;
@@ -834,7 +834,12 @@ static int xemaclite_mdio_setup(struct net_local *lp, struct device *dev)
 	}
 	npp = of_get_parent(np);
 
-	of_address_to_resource(npp, 0, &res);
+	ret = of_address_to_resource(npp, 0, &res);
+	if (ret) {
+		dev_err(dev, "%s resource error!\n",
+			dev->of_node->full_name);
+		return ret;
+	}
 	if (lp->ndev->mem_start != res.start) {
 		struct phy_device *phydev;
 		phydev = of_phy_find_device(lp->phy_node);
@@ -1173,7 +1178,11 @@ static int xemaclite_of_probe(struct platform_device *ofdev)
 	xemaclite_update_address(lp, ndev->dev_addr);
 
 	lp->phy_node = of_parse_phandle(ofdev->dev.of_node, "phy-handle", 0);
-	xemaclite_mdio_setup(lp, &ofdev->dev);
+	rc = xemaclite_mdio_setup(lp, &ofdev->dev);
+	if (rc) {
+		dev_warn(dev, "error registering MDIO bus: %d\n", rc);
+		goto error;
+	}
 
 	dev_info(dev, "MAC address is now %pM\n", ndev->dev_addr);
 
@@ -1197,6 +1206,7 @@ static int xemaclite_of_probe(struct platform_device *ofdev)
 	return 0;
 
 error:
+	of_node_put(lp->phy_node);
 	free_netdev(ndev);
 	return rc;
 }
-- 
2.7.4