Re: [PATCH v7 6/7] power: supply: Add driver for ASUS Transformer battery

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] The driver lacks a MODULE_ALIAS declaration, which breaks module autoloading.
- [Low] Missing NULL check for the devm_kasprintf allocation of the power supply name.
--

commit ccc69cbdb16bd3e704318f7d07abbad8dc370844
Author: Michał Mirosław <mirq-linux@rere.qmqm.pl>

power: supply: Add driver for ASUS Transformer battery

This commit introduces a new power supply driver for the ASUS Transformer
battery. It communicates with the embedded controller via I2C to read battery
status for both the tablet and mobile dock.

> diff --git a/drivers/power/supply/asus-transformer-ec-battery.c b/drivers/power/supply/asus-transformer-ec-battery.c
> new file mode 100644
> index 0000000000000..d08d155f72a3d
> --- /dev/null
> +++ b/drivers/power/supply/asus-transformer-ec-battery.c
[ ... ]
> +static int asus_ec_battery_probe(struct platform_device *pdev)
> +{
[ ... ]
> +	cfg.fwnode = dev_fwnode(dev->parent);
> +	cfg.drv_data = priv;
> +
> +	memcpy(&priv->psy_desc, &asus_ec_battery_desc, sizeof(priv->psy_desc));
> +	priv->psy_desc.name = devm_kasprintf(dev, GFP_KERNEL, "%s-battery",
> +					     priv->ec->name);
> +
> +	priv->battery = devm_power_supply_register(dev, &priv->psy_desc, &cfg);
> +	if (IS_ERR(priv->battery))
> +		return dev_err_probe(dev, PTR_ERR(priv->battery),
> +				     "Failed to register power supply\n");

Is it possible for devm_kasprintf() to fail and return NULL under memory
pressure?

If so, priv->psy_desc.name would become NULL, and devm_power_supply_register()
would return ERR_PTR(-EINVAL) because it checks for !desc->name. This relies
on downstream validation and results in an incorrect error code being
propagated for a memory allocation failure instead of -ENOMEM.

Should there be an explicit NULL check here?

[ ... ]
> +static struct platform_driver asus_ec_battery_driver = {
> +	.driver = {
> +		.name = "asus-transformer-ec-battery",
> +		.pm = &asus_ec_battery_pm_ops,
> +	},
> +	.probe = asus_ec_battery_probe,
> +};
> +module_platform_driver(asus_ec_battery_driver);
> +
> +MODULE_AUTHOR("Michał Mirosław <mirq-linux@rere.qmqm.pl>");
> +MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
> +MODULE_DESCRIPTION("ASUS Transformer's battery driver");
> +MODULE_LICENSE("GPL");

Since this platform driver matches devices purely by name
("asus-transformer-ec-battery") and lacks an id_table or of_match_table,
will userspace tools like udev be able to automatically load this driver
when it is compiled as a module?

Should a MODULE_ALIAS("platform:asus-transformer-ec-battery"); declaration
be added to ensure module autoloading works correctly?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260518095907.36158-1-clamor95@gmail.com?part=6