Re: [PATCH net-next v2 07/10] net: phy: add support for C45-over-C22 transfers

Andrew Lunn
2023-06-24T20:18:15Z

> int __phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
> {
> - int val;
> + struct mii_bus *bus = phydev->mdio.bus;
> + int phy_addr = phydev->mdio.addr;
> + bool check_rc = true;
> + int ret;

Although __phy_read_mmd() is exported as a GPL symbol, it is not in
fact used outside of this file. I think we can easily change it
signature.

> + switch (phydev->access_mode) {

Have access_mode passed in as a parameter. It then becomes a generic
low level helper.

The function which is really exported and expected to by used by PHY
drivers is:

int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum)
{
int ret;

phy_lock_mdio_bus(phydev);
ret = __phy_read_mmd(phydev, devad, regnum);
phy_unlock_mdio_bus(phydev);

return ret;
}
EXPORT_SYMBOL(phy_read_mmd);

This can easily pass phydev->access_mode as a parameter.

> +static int phy_probe_mmd_read(struct mii_bus *bus, int prtad, int devad,
> + u16 regnum, bool c45_over_c22)
> +{

What i don't like is this bool c45_over_c22. Why have both the enum
for the three access modes, and this bool. Pass an access mode.

> + int ret;
> +
> + if (!c45_over_c22)
> + return mdiobus_c45_read(bus, prtad, devad, regnum);
> +
> + mutex_lock(&bus->mdio_lock);
> +
> + ret = __phy_mmd_indirect(bus, prtad, devad, regnum);
> + if (ret)
> + goto out;
> +
> + ret = __mdiobus_read(bus, prtad, MII_MMD_DATA);

And then this just uses the generic low level __phy_read_mmd().

Andrew