[PATCH 1/2] net: phy: Add error checks in the driver

-	mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG, val);
+	err = mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG,
+			    val);
+	if (err < 0)
+		return err;
 
 	return 0;

Do you need to assign err? Why not just

   return mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG,
			val);