Re: [PATCH 3/3] net: phy: mediatek: add support for built-in 2.5G ethernet PHY on MT7988

From: Andrew Lunn
Date: Thu Apr 25 2024 - 11:38:05 EST


> +static int mt7988_2p5ge_phy_config_init(struct phy_device *phydev)
> +{
> + int ret, i;
> + const struct firmware *fw;
> + struct device *dev = &phydev->mdio.dev;
> + struct device_node *np;
> + void __iomem *pmb_addr;
> + void __iomem *md32_en_cfg_base;
> + struct mtk_i2p5ge_phy_priv *priv = phydev->priv;
> + u16 reg;
> + struct pinctrl *pinctrl;

Reverse Christmas Tree please.

> +static int mt7988_2p5ge_phy_config_aneg(struct phy_device *phydev)
> +{
> + bool changed = false;
> + u32 adv;
> + int ret;
> +
> + if (phydev->autoneg == AUTONEG_DISABLE) {
> + /* Configure half duplex with genphy_setup_forced,
> + * because genphy_c45_pma_setup_forced does not support.
> + */

The English in that comment is wrong.

Ah, it appears to be a copy/paste, e.g. from mxl-gpy.c. In fact, a lot
of this function is identical to gpy_config_aneg(). Maybe it should be
pulled out into a helper.

> +static int mt7988_2p5ge_phy_get_features(struct phy_device *phydev)
> +{
> + int ret;
> +
> + ret = genphy_read_abilities(phydev);
> + if (ret)
> + return ret;
> +
> + /* We don't support HDX at MAC layer on mt7988.
> + * So mask phy's HDX capabilities, too.
> + */

This comment seems to contradict the comment above?

Also, this code does not mask anything, it sets bits. What does
genphy_read_abilities() find out about the device? If the hardware
confirms to the standard, it should not indicate is supports 1/2
duplex, genphy_read_abilities() should then not return those link
modes, but it should return 10, 100 and 1000 full duplex.

> + linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT,
> + phydev->supported);
> + linkmode_set_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT,
> + phydev->supported);
> + linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
> + phydev->supported);
> + linkmode_set_bit(ETHTOOL_LINK_MODE_2500baseT_Full_BIT,
> + phydev->supported);
> + linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, phydev->supported);

What does genphy_c45_pma_read_abilities() report about the device?

> +static int mt7988_2p5ge_phy_read_status(struct phy_device *phydev)
> +{
> + int ret;
> +
> + ret = genphy_update_link(phydev);
> + if (ret)
> + return ret;
> +
> + phydev->speed = SPEED_UNKNOWN;
> + phydev->duplex = DUPLEX_UNKNOWN;
> + phydev->pause = 0;
> + phydev->asym_pause = 0;
> +
> + if (phydev->autoneg == AUTONEG_ENABLE) {
> + if (phydev->autoneg_complete) {
> + ret = genphy_c45_read_lpa(phydev);
> + if (ret < 0)
> + return ret;
> +
> + /* Read the link partner's 1G advertisement */
> + ret = phy_read(phydev, MII_STAT1000);
> + if (ret < 0)
> + return ret;
> + mii_stat1000_mod_linkmode_lpa_t(phydev->lp_advertising, ret);

> + } else if (!linkmode_test_bit(ETHTOOL_LINK_MODE_2500baseT_Full_BIT,
> + phydev->advertising) &&
> + linkmode_test_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
> + phydev->advertising)) {
> + extend_an_new_lp_cnt_limit(phydev);
> + }

A comment about what is happening here would be good.

> + } else if (phydev->autoneg == AUTONEG_DISABLE) {
> + linkmode_zero(phydev->lp_advertising);
> + }

This if does not make much sense.

> + ret = phy_read_mmd(phydev, MDIO_MMD_VEND1, MTK_PHY_LINK_STATUS_MISC);
> + if (ret < 0)
> + return ret;
> + phydev->duplex = (ret & MTK_PHY_FDX_ENABLE) ? DUPLEX_FULL : DUPLEX_HALF;

Do does it support half duplex or not?

Andrew