diff mbox series

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

Message ID 20231103195310.948327-2-andriy.shevchenko@linux.intel.com
State New
Headers show
Series [v1,1/4] leds: trigger: gpio: Replace custom code for gpiod_get_optional() | expand

Commit Message

Andy Shevchenko Nov. 3, 2023, 7:53 p.m. UTC
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(-)

Comments

Linus Walleij Nov. 4, 2023, 10:26 p.m. UTC | #1
On Fri, Nov 3, 2023 at 9:03 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> 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>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij
Lee Jones Nov. 23, 2023, 11:05 a.m. UTC | #2
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
>
Andy Shevchenko Nov. 23, 2023, 2:11 p.m. UTC | #3
On Thu, Nov 23, 2023 at 11:05:38AM +0000, Lee Jones wrote:
> On Fri, 03 Nov 2023, Andy Shevchenko wrote:

...

> > -	ret = sscanf(buf, "%u", &desired_brightness);

"%u" (see man sscanf() for the details)

...

> > +	ret = kstrtou8(buf, 10, &desired_brightness);
> 
> Where does 10 come from?

See above.
diff mbox series

Patch

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