Re: [PATCH] pinctrl: pinctrl-generic-mux: Fix provider resource leak on re-parse

[Chancel Liu]

On 9/18/2026 5:02 AM, Frank Li wrote:
> On Wed, Sep 16, 2026 at 12:04:35PM +0900, Chancel Liu wrote:
>> From: Chancel Liu <chancel.liu@xxxxxxx>
>>
> ...
>>
>> +static int mux_pinctrl_probe_dt(struct pinctrl_dev *pctldev,
>> +				struct device_node *np)
>> +{
>> +	struct device *dev = pctldev->dev;
>> +
>> +	for_each_available_child_of_node_scoped(np, grp) {
>> +		struct mux_pin_function *function;
>> +		const char **group_names;
>> +		int ret;
>> +
>> +		function = devm_kzalloc(dev, sizeof(*function), GFP_KERNEL);
>> +		if (!function)
>> +			return -ENOMEM;
>> +
>> +		group_names = devm_kcalloc(dev, 1, sizeof(*group_names), GFP_KERNEL);
>> +		if (!group_names)
>> +			return -ENOMEM;
>> +
>> +		group_names[0] = grp->name;
>> +
>> +		function->mux_state = devm_mux_state_get_from_np(dev, NULL, grp);
>> +		if (IS_ERR(function->mux_state))
>> +			return dev_err_probe(dev, PTR_ERR(function->mux_state),
>> +					     "failed to get mux-state for %pOFn\n",
>> +					     grp);
>> +
>> +		ret = pinctrl_generic_add_group(pctldev, grp->name, NULL, 0, NULL);
>> +		if (ret < 0)
>> +			return dev_err_probe(dev, ret,
>> +					     "failed to add group %pOFn\n", grp);
>> +
>> +		ret = pinmux_generic_add_function(pctldev, grp->name, group_names,
>> +						  1, function);
>> +		if (ret < 0)
>> +			return dev_err_probe(dev, ret,
>> +					     "failed to add function %pOFn\n", grp);
>> +	}
>> +
>> +	return 0;
>> +}
> 
> This method also works, slice difference, if some pin have not used by
> consumer,  old method may save some memory.
> 
> leave to linus to decide which is better way, this one or add free() at
> .dt_free_map()
> 
> Frank

IMHO, the groups and functions of a board-level mux are static and fully
described by the devicetree, so probe time is the natural place to build
them, and dt_node_to_map() can then focus on mapping. Happy to go with
whichever Linus prefers.

Regards,
Chancel Liu