Re: [PATCH 2/2] hwmon: (ltc2992) use fwnode_for_each_available_child_node_scoped()

[Guenter Roeck]

On 5/22/24 02:18, Javier Carrasco wrote:
> The error path from a zero value of the "shunt-resistor-micro-ohms"
> property does not decrement the refcount of the child node.
>
> Instead of adding the missing fwnode_handle_put(), a safer fix for
> future modifications is using the _scoped version of the macro,
> which removes the need for fwnode_handle_put() in all error paths.
>
> The macro defines the child node internally, which removes the need for
> the current child node declaration as well.
>
> Fixes: 10b029020487 ("hwmon: (ltc2992) Avoid division by zero")
> Signed-off-by: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>

I really don't like fixes which depend on an API change.

Guenter

> ---
>   drivers/hwmon/ltc2992.c | 11 +++--------
>   1 file changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/hwmon/ltc2992.c b/drivers/hwmon/ltc2992.c
> index 229aed15d5ca..3feee400ecf8 100644
> --- a/drivers/hwmon/ltc2992.c
> +++ b/drivers/hwmon/ltc2992.c
> @@ -855,24 +855,19 @@ static const struct regmap_config ltc2992_regmap_config = {
>   static int ltc2992_parse_dt(struct ltc2992_state *st)
>   {
>   	struct fwnode_handle *fwnode;
> -	struct fwnode_handle *child;
>   	u32 addr;
>   	u32 val;
>   	int ret;
>   
>   	fwnode = dev_fwnode(&st->client->dev);
>   
> -	fwnode_for_each_available_child_node(fwnode, child) {
> +	fwnode_for_each_available_child_node_scoped(fwnode, child) {
>   		ret = fwnode_property_read_u32(child, "reg", &addr);
> -		if (ret < 0) {
> -			fwnode_handle_put(child);
> +		if (ret < 0)
>   			return ret;
> -		}
>   
> -		if (addr > 1) {
> -			fwnode_handle_put(child);
> +		if (addr > 1)
>   			return -EINVAL;
> -		}
>   
>   		ret = fwnode_property_read_u32(child, "shunt-resistor-micro-ohms", &val);
>   		if (!ret) {