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From:   Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
To:     <davem@davemloft.net>, <kuba@kernel.org>, <michal.simek@xilinx.com>
CC:     <netdev@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <git@xilinx.com>,
        Shravya Kumbham <shravya.kumbham@xilinx.com>,
        Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Subject: [PATCH net-next] net: emaclite: Add error handling for of_address_ and phy read functions
Date:   Tue, 3 Nov 2020 19:01:05 +0530
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From: Shravya Kumbham <shravya.kumbham@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.kumbham@xilinx.com>
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@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