Re: [net-next: PATCH v3 2/6] net: mdiobus: Introduce fwnode_mdbiobus_register()

From: Marcin Wojtas
Date: Wed Jun 23 2021 - 18:14:39 EST


Hi,

śr., 23 cze 2021 o 22:22 Andrew Lunn <andrew@xxxxxxx> napisał(a):
>
> On Mon, Jun 21, 2021 at 07:30:24PM +0200, Marcin Wojtas wrote:
> > This patch introduces a new helper function that
> > wraps acpi_/of_ mdiobus_register() and allows its
> > usage via common fwnode_ interface.
> >
> > Fall back to raw mdiobus_register() in case CONFIG_FWNODE_MDIO
> > is not enabled, in order to satisfy compatibility
> > in all future user drivers.
> >
> > Signed-off-by: Marcin Wojtas <mw@xxxxxxxxxxxx>
> > ---
> > include/linux/fwnode_mdio.h | 12 +++++++++++
> > drivers/net/mdio/fwnode_mdio.c | 22 ++++++++++++++++++++
> > 2 files changed, 34 insertions(+)
> >
> > diff --git a/include/linux/fwnode_mdio.h b/include/linux/fwnode_mdio.h
> > index faf603c48c86..13d4ae8fee0a 100644
> > --- a/include/linux/fwnode_mdio.h
> > +++ b/include/linux/fwnode_mdio.h
> > @@ -16,6 +16,7 @@ int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,
> > int fwnode_mdiobus_register_phy(struct mii_bus *bus,
> > struct fwnode_handle *child, u32 addr);
> >
> > +int fwnode_mdiobus_register(struct mii_bus *bus, struct fwnode_handle *fwnode);
> > #else /* CONFIG_FWNODE_MDIO */
> > int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,
> > struct phy_device *phy,
> > @@ -30,6 +31,17 @@ static inline int fwnode_mdiobus_register_phy(struct mii_bus *bus,
> > {
> > return -EINVAL;
> > }
> > +
> > +static inline int fwnode_mdiobus_register(struct mii_bus *bus,
> > + struct fwnode_handle *fwnode)
> > +{
> > + /*
> > + * Fall back to mdiobus_register() function to register a bus.
> > + * This way, we don't have to keep compat bits around in drivers.
> > + */
> > +
> > + return mdiobus_register(mdio);
> > +}
> > #endif
>
> I looked at this some more, and in the end i decided it was O.K.
>
> > +/**
> > + * fwnode_mdiobus_register - bring up all the PHYs on a given MDIO bus and
> > + * attach them to it.
> > + * @bus: Target MDIO bus.
> > + * @fwnode: Pointer to fwnode of the MDIO controller.
> > + *
> > + * Return values are determined accordingly to acpi_/of_ mdiobus_register()
> > + * operation.
> > + */
> > +int fwnode_mdiobus_register(struct mii_bus *bus, struct fwnode_handle *fwnode)
> > +{
> > + if (is_acpi_node(fwnode))
> > + return acpi_mdiobus_register(bus, fwnode);
> > + else if (is_of_node(fwnode))
> > + return of_mdiobus_register(bus, to_of_node(fwnode));
> > + else
> > + return -EINVAL;
>
> I wounder if here you should call mdiobus_register(mdio), rather than
> -EINVAL?
>
> I don't have a strong opinion.

Currently (and in foreseeable future) we support only DT/ACPI as a
firmware description, reaching the last "else" means something really
wrong. The case of lack of DT/ACPI and the fallback is handled on the
include/linux/fwnode_mdio.h level.

>
> Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
>

Thanks,
Marcin