Re: [PATCH net-next v2 2/4] net: phy: micrel: add EEE configuration support for KSZ9477 variants of PHYs

[<Arun.Ramadoss@microchip.com>]

Hi Oleksij,

On Fri, 2023-01-20 at 10:20 +0100, Oleksij Rempel wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you
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> 
> KSZ9477 variants of PHYs are not completely compatible with generic
> phy_ethtool_get/set_eee() handlers. For example MDIO_PCS_EEE_ABLE
> acts
> like a mirror of MDIO_AN_EEE_ADV register. If MDIO_AN_EEE_ADV set to
> 0,
> MDIO_PCS_EEE_ABLE will be 0 too. It means, if we do
> "ethtool --set-eee lan2 eee off", we won't be able to enable it
> again.
> 
> With this patch, instead of reading MDIO_PCS_EEE_ABLE register, the
> driver will provide proper abilities.
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
>  drivers/net/phy/micrel.c | 81
> ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 81 insertions(+)
> 
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index d5b80c31ab91..dca61a73c144 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -1370,6 +1370,85 @@ static int ksz9131_config_aneg(struct
> phy_device *phydev)
>         return genphy_config_aneg(phydev);
>  }
> 
> +static int ksz9477_set_eee(struct phy_device *phydev, struct
> ethtool_eee *data)
> +{
> +       int old_adv, adv = 0, ret;

nit: you can consider declaring variable in two lines, one with
initialized and other with uninitialized.
int old_adv, ret;
int adv = 0;

> +
> +       ksz9477_get_eee_caps(phydev, data);
> +
> +       old_adv = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV);
> +       if (old_adv < 0)
> +               return old_adv;
> +
> +       if (data->eee_enabled) {
> +               if (!data->advertised)
> +                       adv = ethtool_adv_to_mmd_eee_adv_t(data-
> >supported);
> +               else
> +                       adv = ethtool_adv_to_mmd_eee_adv_t(data-
> >advertised &
> +                                                          data-
> >supported);
> +               /* Mask prohibited EEE modes */
> +               adv &= ~phydev->eee_broken_modes;
> +       }
> +
> +       if (old_adv != adv) {
> +               ret = phy_write_mmd(phydev, MDIO_MMD_AN,
> MDIO_AN_EEE_ADV, adv);
> +               if (ret < 0)
> +                       return ret;
> +
> +               /* Restart autonegotiation so the new modes get sent
> to the
> +                * link partner.
> +                */
> +               if (phydev->autoneg == AUTONEG_ENABLE) {
> +                       ret = phy_restart_aneg(phydev);
> +                       if (ret < 0)
> +                               return ret;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> 
>