Re: [PATCH v1 2/4] leds: trigger: gpio: Convert to use kstrtox()

[Lee Jones <lee@kernel.org>]

On Fri, 03 Nov 2023, Andy Shevchenko wrote:

> sscanf() is a heavy one and moreover requires additional boundary checks.
> Convert driver to use kstrtou8() in gpio_trig_inverted_store().
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/leds/trigger/ledtrig-gpio.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/leds/trigger/ledtrig-gpio.c b/drivers/leds/trigger/ledtrig-gpio.c
> index d91ae7fde3cf..8a30f9228186 100644
> --- a/drivers/leds/trigger/ledtrig-gpio.c
> +++ b/drivers/leds/trigger/ledtrig-gpio.c
> @@ -53,14 +53,12 @@ static ssize_t gpio_trig_brightness_store(struct device *dev,
>  		struct device_attribute *attr, const char *buf, size_t n)
>  {
>  	struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
> -	unsigned desired_brightness;
> +	u8 desired_brightness;
>  	int ret;
>  
> -	ret = sscanf(buf, "%u", &desired_brightness);
> -	if (ret < 1 || desired_brightness > 255) {
> -		dev_err(dev, "invalid value\n");
> -		return -EINVAL;
> -	}
> +	ret = kstrtou8(buf, 10, &desired_brightness);

Where does 10 come from?

> +	if (ret)
> +		return ret;
>  
>  	gpio_data->desired_brightness = desired_brightness;
>  
> -- 
> 2.40.0.1.gaa8946217a0b
> 

-- 
Lee Jones [李琼斯]