Re: [PATCH v4] pmdomain: imx: Fix reference count leak in imx_gpc_probe()

[Frank Li <Frank.li@nxp.com>]

On Thu, Dec 11, 2025 at 04:02:52AM +0000, Wentao Liang wrote:
> of_get_child_by_name() returns a node pointer with refcount incremented.
> Use the __free() attribute to manage the pgc_node reference, ensuring
> automatic of_node_put() cleanup when pgc_node goes out of scope.
>
> This eliminates the need for explicit error handling paths and avoids
> reference count leaks.
>
> Fixes: 721cabf6c660 ("soc: imx: move PGC handling to a new GPC driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>
> ---
> Change in V4:
> - Fix typo error in code
>
> Change in V3:
> - Ensure variable is assigned when using cleanup attribute
>
> Change in V2:
> - Use __free() attribute instead of explicit of_node_put() calls
> ---
>  drivers/pmdomain/imx/gpc.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pmdomain/imx/gpc.c b/drivers/pmdomain/imx/gpc.c
> index f18c7e6e75dd..56a78cc86584 100644
> --- a/drivers/pmdomain/imx/gpc.c
> +++ b/drivers/pmdomain/imx/gpc.c
> @@ -403,13 +403,12 @@ static int imx_gpc_old_dt_init(struct device *dev, struct regmap *regmap,
>  static int imx_gpc_probe(struct platform_device *pdev)
>  {
>  	const struct imx_gpc_dt_data *of_id_data = device_get_match_data(&pdev->dev);
> -	struct device_node *pgc_node;
> +	struct device_node *pgc_node __free(device_node)
> +		= of_get_child_by_name(pdev->dev.of_node, "pgc");
>  	struct regmap *regmap;
>  	void __iomem *base;
>  	int ret;
>
> -	pgc_node = of_get_child_by_name(pdev->dev.of_node, "pgc");
> -
>  	/* bail out if DT too old and doesn't provide the necessary info */
>  	if (!of_property_present(pdev->dev.of_node, "#power-domain-cells") &&
>  	    !pgc_node)
> --
> 2.34.1
>