Re: [PATCH v5 4/5] mfd: max8907: Convert to use device managed poweroff handler

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Medium] mfd: max8907: max8907_i2c_probe() drops
  maxim,system-power-controller check
--

commit fb2af9972c7fa309fa63776f15c1fc76c0092afe
Author: Svyatoslav Ryhel <clamor95@gmail.com>

mfd: max8907: Convert to use device managed poweroff handler

This commit replaces the global pm_power_off assignment in max8907 with
devm_register_power_off_handler() and switches the DT property check from
"maxim,system-power-controller" to of_device_is_system_power_controller().

> diff --git a/drivers/mfd/max8907.c b/drivers/mfd/max8907.c
> index f6d7a4ce9712f..8412dab2133e3 100644
> --- a/drivers/mfd/max8907.c
> +++ b/drivers/mfd/max8907.c

[ ... ]

> @@ -185,8 +192,6 @@ static int max8907_i2c_probe(struct i2c_client *i2c)
>  	struct device *dev = &i2c->dev;
>  	struct max8907 *max8907;
>  	int ret;
> -	bool pm_off = of_property_read_bool(dev->of_node,
> -					"maxim,system-power-controller");
>  
>  	max8907 = devm_kzalloc_obj(dev, struct max8907);
>  	if (!max8907)
> @@ -237,9 +242,10 @@ static int max8907_i2c_probe(struct i2c_client *i2c)
>  	if (ret)
>  		return dev_err_probe(dev, ret, "Failed to add MFD devices\n");
>  
> -	if (pm_off && !pm_power_off) {
> -		max8907_pm_off = max8907;
> -		pm_power_off = max8907_power_off;
> +	if (of_device_is_system_power_controller(dev->of_node)) {
> +		ret = devm_register_power_off_handler(dev, max8907_power_off, max8907);
> +		if (ret)
> +			return dev_err_probe(dev, ret, "failed to register power-off handler\n");
>  	}
>  
>  	return 0;

[Severity: Medium]
Should max8907_i2c_probe() still check for "maxim,system-power-controller"
as a fallback alongside of_device_is_system_power_controller()?

of_device_is_system_power_controller() only checks for the standard
"system-power-controller" property.  In commit "regulator: dt-bindings:
maxim,max8907: Convert to DT schema", Documentation/devicetree/bindings/
regulator/maxim,max8907.yaml marks "maxim,system-power-controller" as
deprecated rather than removed, and commit "mfd: max8907: Remove
platform_data based probing" notes that external DTBs may exist for this
driver.  On any system booting with an existing DTB that uses
"maxim,system-power-controller", this regression causes max8907_i2c_probe()
to skip registering the power-off handler, leaving the board unable to
power off via the PMIC.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261115090147.95337-1-clamor95@gmail.com?part=4