Re: [PATCH v1 1/2] net: mdio: Add the reset function for IPQ MDIO driver

[Jie Luo]

On 8/8/2021 11:27 PM, Andrew Lunn wrote:
> > +static int ipq_mdio_reset(struct mii_bus *bus)
> > +{
> > +	struct ipq4019_mdio_data *priv = bus->priv;
> > +	u32 val;
> > +	int ret;
> > +
> > +	/* To indicate CMN_PLL that ethernet_ldo has been ready if platform resource 1
> > +	 * is specified in the device tree.
> > +	 * */
> > +	if (!IS_ERR(priv->eth_ldo_rdy)) {
> > +		val = readl(priv->eth_ldo_rdy);
> > +		val |= BIT(0);
> > +		writel(val, priv->eth_ldo_rdy);
> > +		fsleep(IPQ_PHY_SET_DELAY_US);
> > +	}
> > +
> > +	/* Configure MDIO clock source frequency if clock is specified in the device tree */
> > +	if (!IS_ERR_OR_NULL(priv->mdio_clk)) {
> > +		ret = clk_set_rate(priv->mdio_clk, IPQ_MDIO_CLK_RATE);
> > +		if (ret)
> > +			return ret;
> > +
> > +		ret = clk_prepare_enable(priv->mdio_clk);
> > +		if (ret)
> > +			return ret;
> > +	}
> These !IS_ERR() are pretty ugly. So
>
> > @@ -182,14 +221,22 @@ 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);
> >   
> > +	priv->mdio_clk = devm_clk_get_optional(&pdev->dev, "gcc_mdio_ahb_clk");
> If this returns an error, it is a real error. You should not ignore
> it. Fail the probe returning the error. That then means when the reset
> function is called priv->mdio_clk contains either a clock, or NULL,
> which the clk API is happy to take. No need for an if.
>
>
> > +
> > +	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> > +	if (res)
> > +		priv->eth_ldo_rdy = devm_ioremap_resource(&pdev->dev, res);
> platform_get_resource() returns a pointer or NULL. There is no error
> code. So
>
> > +	if (!IS_ERR(priv->eth_ldo_rdy)) {
> is actually wrong, should simply become
>
> > +	if (priv->eth_ldo_rdy) {
>    Andrew

Hi Andrew,

Thanks for the kindly review and the comments, will follow it in the 
next patch set.