Re: [PATCH net-next] net: phy: intel-xway: Add RGMII internal delay configuration

From: Andrew Lunn
Date: Fri Jul 09 2021 - 09:33:30 EST


> + /* RX delay *must* be specified if internal delay of RX is used. */
> + if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
> + phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID) {
> + rx_int_delay = phy_get_internal_delay(phydev, dev,
> + &xway_internal_delay[0],
> + delay_size, true);
> +
> + if (rx_int_delay < 0) {
> + phydev_err(phydev, "rx-internal-delay-ps must be specified\n");
> + return rx_int_delay;
> + }
> +
> + val &= ~XWAY_MDIO_MIICTRL_RXSKEW_MASK;
> + val |= rx_int_delay << XWAY_MDIO_MIICTRL_RXSKEW_SHIFT;
> + }

Please don't force the delay property to be present, use the default
of 2ns if it is missing.

> + if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID ||
> + phydev->interface == PHY_INTERFACE_MODE_RGMII_RXID ||
> + phydev->interface == PHY_INTERFACE_MODE_RGMII_TXID)
> + err = phy_write(phydev, XWAY_MDIO_MIICTRL, val);
> +

This is the tricky bit. Do we want to act on PHY_INTERFACE_MODE_RGMII?
At the moment, i would say no, lets see how many patches we get
because of the warning you add. But i think it is worth adding a
comment here, briefly explaining why it is missing.

Andrew