Re: [PATCH net-next v3 4/4] net: dsa: initial support for MT7628 embedded switch

Andrew Lunn
2026-04-30T19:20:04Z

> source "drivers/net/dsa/lantiq/Kconfig"
>
> +config NET_DSA_MT7628
> + tristate "MediaTek MT7628 Embedded Ethernet switch support"
> + select NET_DSA_TAG_MT7628
> + select MEDIATEK_FE_SOC_PHY
> + help
> + This enables support for the built-in Ethernet switch found
> + in the MT7628 SoC.
> +
> config NET_DSA_MT7530
> tristate "MediaTek MT7530 and MT7531 Ethernet switch support"

NET_DSA_MT7628 is > NET_DSA_MT7530 so should come second.

> +static int mt7628_mii_read(struct mii_bus *bus, int port, int regnum)
> +{
> + struct mt7628_esw *esw = bus->priv;
> + int ret;
> + u32 val;
> +
> + ret = regmap_read_poll_timeout(esw->regmap, MT7628_ESW_REG_PCR1, val,
> + !(val & MT7628_ESW_PCR1_RD_DONE), 10,
> + 5000);
> + if (ret)
> + goto out;
> +
> + ret = regmap_write(esw->regmap, MT7628_ESW_REG_PCR0,
> + FIELD_PREP(MT7628_ESW_PCR0_CPU_PHY_REG,
> + regnum) |
> + FIELD_PREP(MT7628_ESW_PCR0_CPU_PHY_ADDR,
> + port) | MT7628_ESW_PCR0_RD_PHY_CMD);
> + if (ret)
> + goto out;
> +
> + ret = regmap_read_poll_timeout(esw->regmap, MT7628_ESW_REG_PCR1, val,
> + (val & MT7628_ESW_PCR1_RD_DONE), 10,
> + 5000);
> +out:
> + if (ret) {
> + dev_err(&bus->dev, "read failed. MDIO timeout?\n");
> + return ret;
> + }
> + return FIELD_GET(MT7628_ESW_PCR1_RD_DATA, val);

This works, but it is an unusual structure. Normally the label is
after the normal exist path, and only deals with errors.

> +}
> +
> +static int mt7628_mii_write(struct mii_bus *bus, int port, int regnum, u16 dat)
> +{
> + ret = regmap_read_poll_timeout(esw->regmap, MT7628_ESW_REG_PCR1, val,
> + (val & MT7628_ESW_PCR1_WT_DONE), 10,
> + 5000);
> +out:
> + if (ret) {
> + dev_err(&bus->dev, "write failed. MDIO timeout?\n");
> + return ret;
> + }
> + return 0;
> +}

Same here.

Otherwise this looks O.K.

Andrew