Re: [PATCH V3 1/2] soc: imx: Add SCU SoC info driver support

[Leonard Crestez]

On 16.05.2019 06:24, Anson Huang wrote:
> Add i.MX SCU SoC info driver to support i.MX8QXP SoC, introduce
> driver dependency into Kconfig as CONFIG_IMX_SCU must be
> selected to support i.MX SCU SoC driver, also need to use
> platform driver model to make sure IMX_SCU driver is probed
> before i.MX SCU SoC driver.

> +#define imx_scu_revision(soc_rev) \
> +	soc_rev ? \
> +	kasprintf(GFP_KERNEL, "%d.%d", (soc_rev >> 4) & 0xf,  soc_rev & 0xf) : \
> +	"unknown"

> +	id = of_match_node(imx_scu_soc_match, pdev->dev.of_node);
> +	data = id->data;
> +	if (data) {
> +		soc_dev_attr->soc_id = data->name;
> +		if (data->soc_revision)
> +			soc_rev = data->soc_revision();
> +	}
> +
> +	soc_dev_attr->revision = imx_scu_revision(soc_rev);
> +	if (!soc_dev_attr->revision)
> +		return -ENODEV;

The imx_scu_revision macro returns either kasprintf or "unknown", never 
NULL. So it's not clear what this return -ENODEV does exactly.

It makes more sense to return -ENODEV if get_soc_revision fails, so 
maybe check "soc_rev != 0" instead?

If you really want to check the kasprintf result then you should return 
-ENOMEM for it. It would be clearer if you dropped the imx_scu_revision 
revision macro and open-coded instead.

--
Regards,
Leonard