Re: [PATCH net-next v7 2/3] net: phy: add support for clause 37 auto-negotiation

From: Tao Ren
Date: Mon Aug 19 2019 - 18:18:26 EST


On 8/11/19 4:40 PM, Tao Ren wrote:
> From: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>
> This patch adds support for clause 37 1000Base-X auto-negotiation.
>
> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
> Signed-off-by: Tao Ren <taoren@xxxxxx>

A kind reminder: could someone help to review the patch when you have bandwidth?


Cheers,

Tao

> ---
> Changes in v7:
> - Update "if (AUTONEG_ENABLE != phydev->autoneg)" to
> "if (phydev->autoneg != AUTONEG_ENABLE)" so checkpatch.pl is happy.
> Changes in v6:
> - add "Signed-off-by: Tao Ren <taoren@xxxxxx>"
> Changes in v1-v5:
> - nothing changed. It's given v5 just to align with the version of
> patch series.
>
> drivers/net/phy/phy_device.c | 139 +++++++++++++++++++++++++++++++++++
> include/linux/phy.h | 5 ++
> 2 files changed, 144 insertions(+)
>
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 252a712d1b2b..301a794b2963 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -1617,6 +1617,40 @@ static int genphy_config_advert(struct phy_device *phydev)
> return changed;
> }
>
> +/**
> + * genphy_c37_config_advert - sanitize and advertise auto-negotiation parameters
> + * @phydev: target phy_device struct
> + *
> + * Description: Writes MII_ADVERTISE with the appropriate values,
> + * after sanitizing the values to make sure we only advertise
> + * what is supported. Returns < 0 on error, 0 if the PHY's advertisement
> + * hasn't changed, and > 0 if it has changed. This function is intended
> + * for Clause 37 1000Base-X mode.
> + */
> +static int genphy_c37_config_advert(struct phy_device *phydev)
> +{
> + u16 adv = 0;
> +
> + /* Only allow advertising what this PHY supports */
> + linkmode_and(phydev->advertising, phydev->advertising,
> + phydev->supported);
> +
> + if (linkmode_test_bit(ETHTOOL_LINK_MODE_1000baseX_Full_BIT,
> + phydev->advertising))
> + adv |= ADVERTISE_1000XFULL;
> + if (linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
> + phydev->advertising))
> + adv |= ADVERTISE_1000XPAUSE;
> + if (linkmode_test_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
> + phydev->advertising))
> + adv |= ADVERTISE_1000XPSE_ASYM;
> +
> + return phy_modify_changed(phydev, MII_ADVERTISE,
> + ADVERTISE_1000XFULL | ADVERTISE_1000XPAUSE |
> + ADVERTISE_1000XHALF | ADVERTISE_1000XPSE_ASYM,
> + adv);
> +}
> +
> /**
> * genphy_config_eee_advert - disable unwanted eee mode advertisement
> * @phydev: target phy_device struct
> @@ -1726,6 +1760,54 @@ int genphy_config_aneg(struct phy_device *phydev)
> }
> EXPORT_SYMBOL(genphy_config_aneg);
>
> +/**
> + * genphy_c37_config_aneg - restart auto-negotiation or write BMCR
> + * @phydev: target phy_device struct
> + *
> + * Description: If auto-negotiation is enabled, we configure the
> + * advertising, and then restart auto-negotiation. If it is not
> + * enabled, then we write the BMCR. This function is intended
> + * for use with Clause 37 1000Base-X mode.
> + */
> +int genphy_c37_config_aneg(struct phy_device *phydev)
> +{
> + int err, changed;
> +
> + if (phydev->autoneg != AUTONEG_ENABLE)
> + return genphy_setup_forced(phydev);
> +
> + err = phy_modify(phydev, MII_BMCR, BMCR_SPEED1000 | BMCR_SPEED100,
> + BMCR_SPEED1000);
> + if (err)
> + return err;
> +
> + changed = genphy_c37_config_advert(phydev);
> + if (changed < 0) /* error */
> + return changed;
> +
> + if (!changed) {
> + /* Advertisement hasn't changed, but maybe aneg was never on to
> + * begin with? Or maybe phy was isolated?
> + */
> + int ctl = phy_read(phydev, MII_BMCR);
> +
> + if (ctl < 0)
> + return ctl;
> +
> + if (!(ctl & BMCR_ANENABLE) || (ctl & BMCR_ISOLATE))
> + changed = 1; /* do restart aneg */
> + }
> +
> + /* Only restart aneg if we are advertising something different
> + * than we were before.
> + */
> + if (changed > 0)
> + return genphy_restart_aneg(phydev);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(genphy_c37_config_aneg);
> +
> /**
> * genphy_aneg_done - return auto-negotiation status
> * @phydev: target phy_device struct
> @@ -1864,6 +1946,63 @@ int genphy_read_status(struct phy_device *phydev)
> }
> EXPORT_SYMBOL(genphy_read_status);
>
> +/**
> + * genphy_c37_read_status - check the link status and update current link state
> + * @phydev: target phy_device struct
> + *
> + * Description: Check the link, then figure out the current state
> + * by comparing what we advertise with what the link partner
> + * advertises. This function is for Clause 37 1000Base-X mode.
> + */
> +int genphy_c37_read_status(struct phy_device *phydev)
> +{
> + int lpa, err, old_link = phydev->link;
> +
> + /* Update the link, but return if there was an error */
> + err = genphy_update_link(phydev);
> + if (err)
> + return err;
> +
> + /* why bother the PHY if nothing can have changed */
> + if (phydev->autoneg == AUTONEG_ENABLE && old_link && phydev->link)
> + return 0;
> +
> + phydev->duplex = DUPLEX_UNKNOWN;
> + phydev->pause = 0;
> + phydev->asym_pause = 0;
> +
> + if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) {
> + lpa = phy_read(phydev, MII_LPA);
> + if (lpa < 0)
> + return lpa;
> +
> + linkmode_mod_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
> + phydev->lp_advertising, lpa & LPA_LPACK);
> + linkmode_mod_bit(ETHTOOL_LINK_MODE_1000baseX_Full_BIT,
> + phydev->lp_advertising, lpa & LPA_1000XFULL);
> + linkmode_mod_bit(ETHTOOL_LINK_MODE_Pause_BIT,
> + phydev->lp_advertising, lpa & LPA_1000XPAUSE);
> + linkmode_mod_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
> + phydev->lp_advertising,
> + lpa & LPA_1000XPAUSE_ASYM);
> +
> + phy_resolve_aneg_linkmode(phydev);
> + } else if (phydev->autoneg == AUTONEG_DISABLE) {
> + int bmcr = phy_read(phydev, MII_BMCR);
> +
> + if (bmcr < 0)
> + return bmcr;
> +
> + if (bmcr & BMCR_FULLDPLX)
> + phydev->duplex = DUPLEX_FULL;
> + else
> + phydev->duplex = DUPLEX_HALF;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(genphy_c37_read_status);
> +
> /**
> * genphy_soft_reset - software reset the PHY via BMCR_RESET bit
> * @phydev: target phy_device struct
> diff --git a/include/linux/phy.h b/include/linux/phy.h
> index 462b90b73f93..81a2921512ee 100644
> --- a/include/linux/phy.h
> +++ b/include/linux/phy.h
> @@ -1077,6 +1077,11 @@ int genphy_suspend(struct phy_device *phydev);
> int genphy_resume(struct phy_device *phydev);
> int genphy_loopback(struct phy_device *phydev, bool enable);
> int genphy_soft_reset(struct phy_device *phydev);
> +
> +/* Clause 37 */
> +int genphy_c37_config_aneg(struct phy_device *phydev);
> +int genphy_c37_read_status(struct phy_device *phydev);
> +
> static inline int genphy_no_soft_reset(struct phy_device *phydev)
> {
> return 0;
>