Re: [PATCH v2] clk: meson: Hold reference returned by of_get_parent()

[Neil Armstrong <narmstrong@baylibre.com>]

On 28/06/2022 16:10, Liang He wrote:
> We should hold the reference returned by of_get_parent() and use it
> to call of_node_put() for refcount balance.
> 
> Fixes: 88e2da81241e ("clk: meson: aoclk: refactor common code into dedicated file")
> Fixes: 6682bd4d443f ("clk: meson: factorise meson64 peripheral clock controller drivers")
> Fixes: bb6eddd1d28c ("clk: meson: meson8b: use the HHI syscon if available")
> 
> Signed-off-by: Liang He <windhl@126.com>
> ---
>   changelog:
>   
>   v2: change the name of 'tp', change the title format, keep reverse christmas tree
>   v1: hold reference returned by of_get_parent()
> 
>   v1-link: https://lore.kernel.org/all/20220624102719.4166125-1-windhl@126.com/
> 
>   Patched files have been compiled test in 5.19rc2.
> 
> 
>   drivers/clk/meson/meson-aoclk.c | 5 ++++-
>   drivers/clk/meson/meson-eeclk.c | 5 ++++-
>   drivers/clk/meson/meson8b.c     | 5 ++++-
>   3 files changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/clk/meson/meson-aoclk.c b/drivers/clk/meson/meson-aoclk.c
> index 27cd2c1f3f61..434cd8f9de82 100644
> --- a/drivers/clk/meson/meson-aoclk.c
> +++ b/drivers/clk/meson/meson-aoclk.c
> @@ -38,6 +38,7 @@ int meson_aoclkc_probe(struct platform_device *pdev)
>   	struct meson_aoclk_reset_controller *rstc;
>   	struct meson_aoclk_data *data;
>   	struct device *dev = &pdev->dev;
> +	struct device_node *np;
>   	struct regmap *regmap;
>   	int ret, clkid;
>   
> @@ -49,7 +50,9 @@ int meson_aoclkc_probe(struct platform_device *pdev)
>   	if (!rstc)
>   		return -ENOMEM;
>   
> -	regmap = syscon_node_to_regmap(of_get_parent(dev->of_node));
> +	np = of_get_parent(dev->of_node);
> +	regmap = syscon_node_to_regmap(np);
> +	of_node_put(np);
>   	if (IS_ERR(regmap)) {
>   		dev_err(dev, "failed to get regmap\n");
>   		return PTR_ERR(regmap);
> diff --git a/drivers/clk/meson/meson-eeclk.c b/drivers/clk/meson/meson-eeclk.c
> index 8d5a5dab955a..0e5e6b57eb20 100644
> --- a/drivers/clk/meson/meson-eeclk.c
> +++ b/drivers/clk/meson/meson-eeclk.c
> @@ -18,6 +18,7 @@ int meson_eeclkc_probe(struct platform_device *pdev)
>   {
>   	const struct meson_eeclkc_data *data;
>   	struct device *dev = &pdev->dev;
> +	struct device_node *np;
>   	struct regmap *map;
>   	int ret, i;
>   
> @@ -26,7 +27,9 @@ int meson_eeclkc_probe(struct platform_device *pdev)
>   		return -EINVAL;
>   
>   	/* Get the hhi system controller node */
> -	map = syscon_node_to_regmap(of_get_parent(dev->of_node));
> +	np = of_get_parent(dev->of_node);
> +	map = syscon_node_to_regmap(np);
> +	of_node_put(np);
>   	if (IS_ERR(map)) {
>   		dev_err(dev,
>   			"failed to get HHI regmap\n");
> diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c
> index 8f3b7a94a667..827e78fb16a8 100644
> --- a/drivers/clk/meson/meson8b.c
> +++ b/drivers/clk/meson/meson8b.c
> @@ -3792,12 +3792,15 @@ static void __init meson8b_clkc_init_common(struct device_node *np,
>   			struct clk_hw_onecell_data *clk_hw_onecell_data)
>   {
>   	struct meson8b_clk_reset *rstc;
> +	struct device_node *parent_np;
>   	const char *notifier_clk_name;
>   	struct clk *notifier_clk;
>   	struct regmap *map;
>   	int i, ret;
>   
> -	map = syscon_node_to_regmap(of_get_parent(np));
> +	parent_np = of_get_parent(np);
> +	map = syscon_node_to_regmap(parent_np);
> +	of_node_put(parent_np);
>   	if (IS_ERR(map)) {
>   		pr_err("failed to get HHI regmap - Trying obsolete regs\n");
>   		return;

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>