Re: [PATCH v2 1/5] net: mdio: ipq4019: move eth_ldo_rdy before MDIO bus register

[Maxime Chevallier]

Hello Russell,

On Tue, 12 Dec 2023 19:11:15 +0000
"Russell King (Oracle)" <linux@xxxxxxxxxxxxxxx> wrote:

> On Tue, Dec 12, 2023 at 01:50:01PM +0100, Maxime Chevallier wrote:
> > Hello,
> > 
> > On Tue, 12 Dec 2023 19:51:46 +0800
> > Luo Jie <quic_luoj@xxxxxxxxxxx> wrote:  
> > > @@ -252,11 +244,32 @@ static int ipq4019_mdio_probe(struct platform_device *pdev)
> > >  	if (IS_ERR(priv->mdio_clk))
> > >  		return PTR_ERR(priv->mdio_clk);
> > >  
> > > -	/* The platform resource is provided on the chipset IPQ5018 */
> > > -	/* This resource is optional */
> > > -	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> > > -	if (res)
> > > -		priv->eth_ldo_rdy = devm_ioremap_resource(&pdev->dev, res);
> > > +	/* These platform resources are provided on the chipset IPQ5018 or
> > > +	 * IPQ5332.
> > > +	 */
> > > +	/* This resource are optional */
> > > +	for (index = 0; index < ETH_LDO_RDY_CNT; index++) {
> > > +		res = platform_get_resource(pdev, IORESOURCE_MEM, index + 1);
> > > +		if (res) {
> > > +			priv->eth_ldo_rdy[index] = devm_ioremap(&pdev->dev,
> > > +								res->start,
> > > +								resource_size(res));  
> > 
> > You can simplify that sequence by using
> > devm_platform_get_and_ioremap_resource(), which will do both the
> > platform_get_resource and the devm_ioremap at once for you.  
> 
> Sadly it can't if resources are optional. __devm_ioremap_resource()
> which will be capped by devm_platform_get_and_ioremap_resource() will
> be passed a NULL 'res', which will lead to:
> 
>         if (!res || resource_type(res) != IORESOURCE_MEM) {
>                 dev_err(dev, "invalid resource %pR\n", res);
>                 return IOMEM_ERR_PTR(-EINVAL);
>         }
> 
> There isn't an "optional" version of
> devm_platform_get_and_ioremap_resource().
> 

Ah right, I missed that part indeed. Sorry for the noise then, and
thanks for double-checking :)

Best regards,

Maxime