Re: [net-next PATCH v3 5/5] net: mdiobus: Introduce fwnode_mdiobus_register_phy()

[Andy Shevchenko]

On Tue, May 5, 2020 at 4:30 PM Calvin Johnson
<calvin.johnson@xxxxxxxxxxx> wrote:
>
> Introduce fwnode_mdiobus_register_phy() to register PHYs on the
> mdiobus. From the compatible string, identify whether the PHY is
> c45 and based on this create a PHY device instance which is
> registered on the mdiobus.

...

> +int fwnode_mdiobus_register_phy(struct mii_bus *bus,
> +                               struct fwnode_handle *child, u32 addr)
> +{
> +       struct phy_device *phy;

> +       bool is_c45 = false;

Redundant assignment, see below.

> +       const char *cp;
> +       u32 phy_id;
> +       int rc;
> +

> +       fwnode_property_read_string(child, "compatible", &cp);

Consider rc = ...; otherwise you will have UB below.

> +       if (!strcmp(cp, "ethernet-phy-ieee802.3-c45"))

UB!

> +               is_c45 = true;

is_c45 = !(rc || strcmp(...));

> +       if (!is_c45 && !fwnode_get_phy_id(child, &phy_id))

Perhaps positive conditional

if (is_c45 || fwnode_...(...))
  get_phy_device();
else
  ...

> +               phy = phy_device_create(bus, addr, phy_id, 0, NULL);
> +       else
> +               phy = get_phy_device(bus, addr, is_c45);
> +       if (IS_ERR(phy))
> +               return PTR_ERR(phy);
> +
> +       phy->irq = bus->irq[addr];
> +
> +       /* Associate the fwnode with the device structure so it
> +        * can be looked up later.
> +        */
> +       phy->mdio.dev.fwnode = child;
> +
> +       /* All data is now stored in the phy struct, so register it */
> +       rc = phy_device_register(phy);
> +       if (rc) {
> +               phy_device_free(phy);

> +               fwnode_handle_put(child);

Shouldn't mdio.dev.fwnode be put rather than child (yes, I see the assignment)

> +               return rc;
> +       }
> +
> +       dev_dbg(&bus->dev, "registered phy at address %i\n", addr);
> +
> +       return 0;
> +}

-- 
With Best Regards,
Andy Shevchenko