Re: [PATCH v2 5/5] hwmon: (pmbus/adm1266) include adapter number in GPIO line label

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Critical] Changing the generated GPIO line names breaks backwards compatibility for userspace tools and scripts.
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commit c155c76ac978e1fe6990333ff1cb0db4a1c40a1e
Author: Abdurrahman Hussain <abdurrahman@nexthop.ai>

hwmon: (pmbus/adm1266) include adapter number in GPIO line label
    
This commit updates the GPIO line labels for the ADM1266 driver to include
the I2C adapter number, in addition to the slave address. This is intended
to disambiguate labels when multiple devices use the same 7-bit address on
different buses.

> The label is purely informational (visible via gpioinfo and the
> gpiochip /sys/class/gpio name); no DT or ABI consumer parses it.

Does changing the generated GPIO line names risk breaking backwards
compatibility for userspace tools and scripts? 

These names are exposed to userspace via the GPIO chardev API and sysfs, and
userspace tools (such as libgpiod) or custom scripts can request GPIO lines
by their names. Modifying these names might break existing userspace
deployments that rely on the old naming convention.

> diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
> index 0dfb02db86837..479e768ff87ca 100644
> --- a/drivers/hwmon/pmbus/adm1266.c
> +++ b/drivers/hwmon/pmbus/adm1266.c
> @@ -292,8 +292,9 @@ static int adm1266_config_gpio(struct adm1266_data *data)
>  	int i;
>  
>  	for (i = 0; i < ARRAY_SIZE(data->gpio_names); i++) {
> -		gpio_name = devm_kasprintf(&data->client->dev, GFP_KERNEL, "adm1266-%x-%s",
> -					   data->client->addr, adm1266_names[i]);
> +		gpio_name = devm_kasprintf(&data->client->dev, GFP_KERNEL, "adm1266-%d-%x-%s",
> +					   data->client->adapter->nr, data->client->addr,
> +					   adm1266_names[i]);

Could this naming format change cause regressions for userspace applications
that are already matching on the previous adm1266-%x-%s format?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260510-adm1266-v2-0-3a22b903c2f1@nexthop.ai?part=5