Re: [PATCH net-next] net: mdio: mscc-miim: Use devm_platform_get_and_ioremap_resource()

[Yang Yingliang]

Hi,

On 2021/6/11 0:01, Andrew Lunn wrote:
> > -	dev->regs = devm_ioremap_resource(&pdev->dev, res);
> > +	dev->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
> >   	if (IS_ERR(dev->regs)) {
> Here, only dev->regs is considered.
>
> >   		dev_err(&pdev->dev, "Unable to map MIIM registers\n");
> >   		return PTR_ERR(dev->regs);
> >   	}
>
>
> > +	dev->phy_regs = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
> > +	if (res && IS_ERR(dev->phy_regs)) {
> Here you look at both res and dev->phy_regs.
>
> This seems inconsistent. Can devm_platform_get_and_ioremap_resource()
> return success despite res being NULL?
No, if res is NULL, devm_platform_get_and_ioremap_resource() returns failed.
But, before this patch, if the internal phy res is NULL, it doesn't 
return error
code, so I checked the res to make sure it doesn't change the origin 
code logic.

Thanks,
Yang
>         Andrew
> .