[PATCH net-next] net: emaclite: Add error handling for of_address_ and phy read functions

[Radhey Shyam Pandey]

From: Shravya Kumbham <shravya.kumb...@xilinx.com>

Add ret variable, conditions to check the return value and it's error
path for of_address_to_resource() and phy_read() functions.

Addresses-Coverity: Event check_return value.
Signed-off-by: Shravya Kumbham <shravya.kumb...@xilinx.com>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pan...@xilinx.com>
---
 drivers/net/ethernet/xilinx/xilinx_emaclite.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/xilinx_emaclite.c 
b/drivers/net/ethernet/xilinx/xilinx_emaclite.c
index 0c26f5b..fc5ccd1 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 +834,13 @@ 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);
+               of_node_put(lp->phy_node);
+               return ret;
+       }
        if (lp->ndev->mem_start != res.start) {
                struct phy_device *phydev;
                phydev = of_phy_find_device(lp->phy_node);
@@ -923,7 +929,7 @@ static int xemaclite_open(struct net_device *dev)
        xemaclite_disable_interrupts(lp);
 
        if (lp->phy_node) {
-               u32 bmcr;
+               int bmcr;
 
                lp->phy_dev = of_phy_connect(lp->ndev, lp->phy_node,
                                             xemaclite_adjust_link, 0,
@@ -945,6 +951,13 @@ static int xemaclite_open(struct net_device *dev)
 
                /* Restart auto negotiation */
                bmcr = phy_read(lp->phy_dev, MII_BMCR);
+               if (bmcr < 0) {
+                       dev_err(&lp->ndev->dev, "phy_read failed\n");
+                       phy_disconnect(lp->phy_dev);
+                       lp->phy_dev = NULL;
+
+                       return bmcr;
+               }
                bmcr |= (BMCR_ANENABLE | BMCR_ANRESTART);
                phy_write(lp->phy_dev, MII_BMCR, bmcr);
 
-- 
2.7.4