Re: [PATCH net-next 6/6] net: phy: added ethtool master-slave configuration support

[<Arun.Ramadoss@microchip.com>]

Hi Andrew,

On Fri, 2022-03-04 at 14:13 +0100, Andrew Lunn wrote:
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> 
> > +static int lan87xx_read_master_slave(struct phy_device *phydev)
> > +{
> > +     int rc = 0;
> > +
> > +     phydev->master_slave_get = MASTER_SLAVE_CFG_UNKNOWN;
> > +     phydev->master_slave_state = MASTER_SLAVE_STATE_UNKNOWN;
> > +
> > +     rc = phy_read(phydev, MII_CTRL1000);
> > +     if (rc < 0)
> > +             return rc;
> > +
> > +     if (rc & CTL1000_AS_MASTER)
> > +             phydev->master_slave_get =
> > MASTER_SLAVE_CFG_MASTER_FORCE;
> > +     else
> > +             phydev->master_slave_get =
> > MASTER_SLAVE_CFG_SLAVE_FORCE;
> > +
> > +     rc = phy_read(phydev, MII_STAT1000);
> > +     if (rc < 0)
> > +             return rc;
> > +
> > +     if (rc & LPA_1000MSRES)
> > +             phydev->master_slave_state =
> > MASTER_SLAVE_STATE_MASTER;
> > +     else
> > +             phydev->master_slave_state =
> > MASTER_SLAVE_STATE_SLAVE;
> > +
> > +     return rc;
> > +}
> 
> It looks like you can just call genphy_read_master_slave()? Or am i
> missing some subtle difference?

Thanks for the comment.

genphy_read_master_slave() and genphy_setup_master_slave() functions
first check for whether phy is gigabit capable. If no, it returns.
LAN87XX is not gigabit capable, so I replicated the genphy function and
removed only the gigabit capable check. I took nxp-tja11xx code as
reference, which has similar implementation.

> 
> > +static int lan87xx_config_aneg(struct phy_device *phydev)
> > +{
> > +     u16 ctl = 0;
> > +     int rc;
> > +
> > +     switch (phydev->master_slave_set) {
> > +     case MASTER_SLAVE_CFG_MASTER_FORCE:
> > +             ctl |= CTL1000_AS_MASTER;
> > +             break;
> > +     case MASTER_SLAVE_CFG_SLAVE_FORCE:
> > +             break;
> > +     case MASTER_SLAVE_CFG_UNKNOWN:
> > +     case MASTER_SLAVE_CFG_UNSUPPORTED:
> > +             return 0;
> > +     default:
> > +             phydev_warn(phydev, "Unsupported Master/Slave
> > mode\n");
> > +             return -EOPNOTSUPP;
> > +     }
> > +
> > +     rc = phy_modify_changed(phydev, MII_CTRL1000,
> > CTL1000_AS_MASTER, ctl);
> > +     if (rc == 1)
> > +             rc = genphy_soft_reset(phydev);
> > +
> > +     return rc;
> > +}
> 
> Please use genphy_setup_master_slave()
> 
>        Andrew