Hi Luo For a patchset, netdev wants to see a patch 0/X which describes the big picture. What is the patchset as a whole doing. > +static int ipq_mdio_reset(struct mii_bus *bus) > +{ > + struct ipq4019_mdio_data *priv = bus->priv; > + struct device *dev = bus->parent; > + struct gpio_desc *reset_gpio; > + u32 val; > + int i, ret; > + > + /* To indicate CMN_PLL that ethernet_ldo has been ready if needed */ > + if (!IS_ERR(priv->eth_ldo_rdy)) { > + val = readl(priv->eth_ldo_rdy); > + val |= BIT(0); > + writel(val, priv->eth_ldo_rdy); > + fsleep(QCA_PHY_SET_DELAY_US); > + } > + > + /* Reset GEPHY if need */ > + if (!IS_ERR(priv->reset_ctrl)) { > + reset_control_assert(priv->reset_ctrl); > + fsleep(QCA_PHY_SET_DELAY_US); > + reset_control_deassert(priv->reset_ctrl); > + fsleep(QCA_PHY_SET_DELAY_US); > + } What exactly is being reset here? Which is GEPHY? The MDIO bus master driver should not be touching any Ethernet PHYs. All it provides is a bus, nothing more. > + > + /* Configure MDIO clock frequency */ > + if (!IS_ERR(priv->mdio_clk)) { > + ret = clk_set_rate(priv->mdio_clk, QCA_MDIO_CLK_RATE); > + if (ret) > + return ret; > + > + ret = clk_prepare_enable(priv->mdio_clk); > + if (ret) > + return ret; > + } > + > + /* Reset PHYs by gpio pins */ > + for (i = 0; i < gpiod_count(dev, "phy-reset"); i++) { > + reset_gpio = gpiod_get_index_optional(dev, "phy-reset", i, GPIOD_OUT_HIGH); > + if (IS_ERR(reset_gpio)) > + continue; > + gpiod_set_value_cansleep(reset_gpio, 0); > + fsleep(QCA_PHY_SET_DELAY_US); > + gpiod_set_value_cansleep(reset_gpio, 1); > + fsleep(QCA_PHY_SET_DELAY_US); > + gpiod_put(reset_gpio); > + } No, there is common code in phylib to do that. > static int ipq4019_mdio_probe(struct platform_device *pdev) > { > struct ipq4019_mdio_data *priv; > struct mii_bus *bus; > + struct resource *res; > int ret; > > bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*priv)); > @@ -182,14 +244,23 @@ static int ipq4019_mdio_probe(struct platform_device *pdev) > return -ENOMEM; > > priv = bus->priv; > + priv->eth_ldo_rdy = IOMEM_ERR_PTR(-EINVAL); > > priv->membase = devm_platform_ioremap_resource(pdev, 0); > if (IS_ERR(priv->membase)) > return PTR_ERR(priv->membase); > > + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); > + if (res) > + priv->eth_ldo_rdy = devm_ioremap_resource(&pdev->dev, res); > + > + priv->reset_ctrl = devm_reset_control_get_exclusive(&pdev->dev, "gephy_mdc_rst"); > + priv->mdio_clk = devm_clk_get(&pdev->dev, "gcc_mdio_ahb_clk"); You probably want to use devm_clk_get_optional(). Andrew