Re: [PATCH 2/2] net: ti: icssg-prueth: Add ICSSG ethernet driver

From: Andrew Lunn
Date: Fri May 06 2022 - 12:50:06 EST


> +static int prueth_config_rgmiidelay(struct prueth *prueth,
> + struct device_node *eth_np,
> + phy_interface_t phy_if)
> +{
> + struct device *dev = prueth->dev;
> + struct regmap *ctrl_mmr;
> + u32 rgmii_tx_id = 0;
> + u32 icssgctrl_reg;
> +
> + if (!phy_interface_mode_is_rgmii(phy_if))
> + return 0;
> +
> + ctrl_mmr = syscon_regmap_lookup_by_phandle(eth_np, "ti,syscon-rgmii-delay");
> + if (IS_ERR(ctrl_mmr)) {
> + dev_err(dev, "couldn't get ti,syscon-rgmii-delay\n");
> + return -ENODEV;
> + }
> +
> + if (of_property_read_u32_index(eth_np, "ti,syscon-rgmii-delay", 1,
> + &icssgctrl_reg)) {
> + dev_err(dev, "couldn't get ti,rgmii-delay reg. offset\n");
> + return -ENODEV;
> + }
> +
> + if (phy_if == PHY_INTERFACE_MODE_RGMII_ID ||
> + phy_if == PHY_INTERFACE_MODE_RGMII_TXID)
> + rgmii_tx_id |= ICSSG_CTRL_RGMII_ID_MODE;
> +
> + regmap_update_bits(ctrl_mmr, icssgctrl_reg, ICSSG_CTRL_RGMII_ID_MODE, rgmii_tx_id);

I know we discussed this before. Why are you adding a delay here in
the MAC? If you do add the delay here, you need to mask what you pass
to phy_connect(), otherwise the PHY is also going to add a delay for
"id" and "txid".

In general, it is best to leave all delays to the PHY.

Andrew