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

From: Calvin Johnson
Date: Thu May 07 2020 - 03:44:56 EST


On Tue, May 05, 2020 at 05:22:00PM +0300, Andy Shevchenko wrote:
> 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!

Thanks for the comments! I've considered all of them.
What is UB, by the way? :)-

Regards
Calvin