linux-kernel - Re: [RESEND PATCH V2] leds: sc27xx: Move mutex

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Date:   Thu, 12 Oct 2023 15:29:44 +0800
From:   Baolin Wang <baolin.wang@...ux.alibaba.com>
To:     Chunyan Zhang <chunyan.zhang@...soc.com>,
        Pavel Machek <pavel@....cz>, Lee Jones <lee@...nel.org>
Cc:     linux-leds@...r.kernel.org, Orson Zhai <orsonzhai@...il.com>,
        Chunyan Zhang <zhang.lyra@...il.com>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [RESEND PATCH V2] leds: sc27xx: Move mutex_init() to the end of
 probe



On 10/12/2023 11:47 AM, Chunyan Zhang wrote:
> Move the mutex_init() to avoid redundant mutex_destroy() calls after
> that for each time the probe fails.
> 
> Signed-off-by: Chunyan Zhang <chunyan.zhang@...soc.com>
> ---
> Rebased onto linux-next.
> 
> V2:
> - Move the mutex_init() to the end of .probe() instead of adding
> mutex_destroy() according to Lee's comments.
> ---
>   drivers/leds/leds-sc27xx-bltc.c | 9 ++++-----
>   1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/leds/leds-sc27xx-bltc.c b/drivers/leds/leds-sc27xx-bltc.c
> index af1f00a2f328..ef57e57ecf07 100644
> --- a/drivers/leds/leds-sc27xx-bltc.c
> +++ b/drivers/leds/leds-sc27xx-bltc.c
> @@ -296,7 +296,6 @@ static int sc27xx_led_probe(struct platform_device *pdev)
>   		return -ENOMEM;
>   
>   	platform_set_drvdata(pdev, priv);
> -	mutex_init(&priv->lock);
>   	priv->base = base;
>   	priv->regmap = dev_get_regmap(dev->parent, NULL);
>   	if (!priv->regmap) {
> @@ -309,13 +308,11 @@ static int sc27xx_led_probe(struct platform_device *pdev)
>   		err = of_property_read_u32(child, "reg", &reg);
>   		if (err) {
>   			of_node_put(child);
> -			mutex_destroy(&priv->lock);
>   			return err;
>   		}
>   
>   		if (reg >= SC27XX_LEDS_MAX || priv->leds[reg].active) {
>   			of_node_put(child);
> -			mutex_destroy(&priv->lock);
>   			return -EINVAL;
>   		}
>   
> @@ -325,9 +322,11 @@ static int sc27xx_led_probe(struct platform_device *pdev)
>   
>   	err = sc27xx_led_register(dev, priv);
>   	if (err)
> -		mutex_destroy(&priv->lock);
> +		return err;
>   
> -	return err;
> +	mutex_init(&priv->lock);

I think it is better to prepare all the required resources before 
registering the led device, what I mean is moving mutex_init() before 
calling sc27xx_led_register().