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

[Denis Kirjanov]

On 11/17/20, Radhey Shyam Pandey <radhey.shyam.pandey at xilinx.com> wrote:
> 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;
> +	}

npp is not returned to of_node_put() in the error case below

>  	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
>
>