hwmon: (pwm-fan) Add missing check for device_property_read_u32_array

[PATCH] hwmon: (pwm-fan) Add missing check for device_property_read_u32_array

Posted by Chen Ni 1 week, 2 days ago

Add check for the return value of device_property_read_u32_array() and
return the error if it fails in order to catch the error.

Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
---
 drivers/hwmon/pwm-fan.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 37269db2de84..3535007f5c37 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -609,8 +609,11 @@ static int pwm_fan_probe(struct platform_device *pdev)
 		for (i = 0; i < ctx->tach_count; i++)
 			ctx->pulses_per_revolution[i] = 2;
 
-		device_property_read_u32_array(dev, "pulses-per-revolution",
-					       ctx->pulses_per_revolution, ctx->tach_count);
+		ret = device_property_read_u32_array(dev, "pulses-per-revolution",
+						     ctx->pulses_per_revolution, ctx->tach_count);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "Failed to read pulses-per-revolution\n");
 	}
 
 	channels = devm_kcalloc(dev, channel_count + 1,
-- 
2.25.1

Re: [PATCH] hwmon: (pwm-fan) Add missing check for device_property_read_u32_array

Posted by Guenter Roeck 1 week, 1 day ago

On Wed, Jan 28, 2026 at 03:26:10PM +0800, Chen Ni wrote:
> Add check for the return value of device_property_read_u32_array() and
> return the error if it fails in order to catch the error.
> 
> Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
> ---
>  drivers/hwmon/pwm-fan.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
> index 37269db2de84..3535007f5c37 100644
> --- a/drivers/hwmon/pwm-fan.c
> +++ b/drivers/hwmon/pwm-fan.c
> @@ -609,8 +609,11 @@ static int pwm_fan_probe(struct platform_device *pdev)
>  		for (i = 0; i < ctx->tach_count; i++)
>  			ctx->pulses_per_revolution[i] = 2;
>  
> -		device_property_read_u32_array(dev, "pulses-per-revolution",
> -					       ctx->pulses_per_revolution, ctx->tach_count);
> +		ret = device_property_read_u32_array(dev, "pulses-per-revolution",
> +						     ctx->pulses_per_revolution, ctx->tach_count);
> +		if (ret)
> +			return dev_err_probe(dev, ret,
> +					     "Failed to read pulses-per-revolution\n");

NACK

This would defeat the purpose of setting the default a couple of lines above.

Guenter

>  	}
>  
>  	channels = devm_kcalloc(dev, channel_count + 1,
> -- 
> 2.25.1
> 
>

Re: [PATCH] hwmon: (pwm-fan) Add missing check for device_property_read_u32_array

Posted by Markus Elfring 1 week, 2 days ago

> Add check for the return value of device_property_read_u32_array() and
> return the error if it fails in order to catch the error.

* Were any source code analysis tools involved here?

* Did anything hinder to add any tags (like “Fixes” and “Cc”) accordingly?


Regards,
Markus