linux-kernel - Re: [PATCH 2/2] cpufreq: sun50i: replace of_node

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Message-ID: <20240510184213.68f92cab@donnerap.manchester.arm.com>
Date: Fri, 10 May 2024 18:42:13 +0100
From: Andre Przywara <andre.przywara@....com>
To: Javier Carrasco <javier.carrasco.cruz@...il.com>
Cc: Yangtao Li <tiny.windzz@...il.com>, "Rafael J. Wysocki"
 <rafael@...nel.org>, Viresh Kumar <viresh.kumar@...aro.org>, Chen-Yu Tsai
 <wens@...e.org>, Jernej Skrabec <jernej.skrabec@...il.com>, Samuel Holland
 <samuel@...lland.org>, Jonathan Cameron <Jonathan.Cameron@...wei.com>,
 linux-pm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
 linux-sunxi@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] cpufreq: sun50i: replace of_node_put() with
 automatic cleanup handler

On Fri, 03 May 2024 19:52:33 +0200
Javier Carrasco <javier.carrasco.cruz@...il.com> wrote:

Hi,

> Make use of the __free() cleanup handler to automatically free nodes
> when they get out of scope.

Looks alright, the last function is now particularly neat.

> Signed-off-by: Javier Carrasco <javier.carrasco.cruz@...il.com>

Reviewed-by: Andre Przywara <andre.przywara@....com>

I haven't tested the error paths yet, but it certainly boots fine on an
OrangePi Zero3.

Cheers,
Andre

> ---
>  drivers/cpufreq/sun50i-cpufreq-nvmem.c | 25 ++++++++-----------------
>  1 file changed, 8 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/cpufreq/sun50i-cpufreq-nvmem.c b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> index ef83e4bf2639..eb47c193269c 100644
> --- a/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> +++ b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> @@ -131,14 +131,14 @@ static const struct of_device_id cpu_opp_match_list[] = {
>  static bool dt_has_supported_hw(void)
>  {
>  	bool has_opp_supported_hw = false;
> -	struct device_node *np;
>  	struct device *cpu_dev;
>  
>  	cpu_dev = get_cpu_device(0);
>  	if (!cpu_dev)
>  		return false;
>  
> -	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
> +	struct device_node *np __free(device_node) =
> +		dev_pm_opp_of_get_opp_desc_node(cpu_dev);
>  	if (!np)
>  		return false;
>  
> @@ -149,8 +149,6 @@ static bool dt_has_supported_hw(void)
>  		}
>  	}
>  
> -	of_node_put(np);
> -
>  	return has_opp_supported_hw;
>  }
>  
> @@ -165,7 +163,6 @@ static int sun50i_cpufreq_get_efuse(void)
>  	const struct sunxi_cpufreq_data *opp_data;
>  	struct nvmem_cell *speedbin_nvmem;
>  	const struct of_device_id *match;
> -	struct device_node *np;
>  	struct device *cpu_dev;
>  	u32 *speedbin;
>  	int ret;
> @@ -174,19 +171,18 @@ static int sun50i_cpufreq_get_efuse(void)
>  	if (!cpu_dev)
>  		return -ENODEV;
>  
> -	np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
> +	struct device_node *np __free(device_node) =
> +		dev_pm_opp_of_get_opp_desc_node(cpu_dev);
>  	if (!np)
>  		return -ENOENT;
>  
>  	match = of_match_node(cpu_opp_match_list, np);
> -	if (!match) {
> -		of_node_put(np);
> +	if (!match)
>  		return -ENOENT;
> -	}
> +
>  	opp_data = match->data;
>  
>  	speedbin_nvmem = of_nvmem_cell_get(np, NULL);
> -	of_node_put(np);
>  	if (IS_ERR(speedbin_nvmem))
>  		return dev_err_probe(cpu_dev, PTR_ERR(speedbin_nvmem),
>  				     "Could not get nvmem cell\n");
> @@ -301,14 +297,9 @@ MODULE_DEVICE_TABLE(of, sun50i_cpufreq_match_list);
>  
>  static const struct of_device_id *sun50i_cpufreq_match_node(void)
>  {
> -	const struct of_device_id *match;
> -	struct device_node *np;
> -
> -	np = of_find_node_by_path("/");
> -	match = of_match_node(sun50i_cpufreq_match_list, np);
> -	of_node_put(np);
> +	struct device_node *np __free(device_node) = of_find_node_by_path("/");
>  
> -	return match;
> +	return of_match_node(sun50i_cpufreq_match_list, np);
>  }
>  
>  /*
>