Re: [PATCH] hwmon: (ina3221) Clamp shunt resistor value from DT

[Guenter Roeck]

On Mon, Oct 08, 2018 at 01:05:37PM -0700, Nicolin Chen wrote:
> The input->shunt_resistor is int type while the value from DT is
> unsigned int. Meanwhile, a divide-by-zero error would happen if
> the value is 0. So this patch just simply clamps the value.
> 

I think it would be better to validate the numbers here instead of 
silently accepting bad values, and return -EINVAL if the property value
is bad.

Thanks,
Guenter

> Signed-off-by: Nicolin Chen 
> ---
>  drivers/hwmon/ina3221.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
> index c3a497aed345..ce8f0a8c4982 100644
> --- a/drivers/hwmon/ina3221.c
> +++ b/drivers/hwmon/ina3221.c
> @@ -536,8 +536,10 @@ static int ina3221_probe_child_from_dt(struct device 
> *dev,
>   of_property_read_string(child, "label", >label);
>  
>   /* Overwrite default shunt resistor value optionally */
> - if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", ))
> + if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", )) {
> + val = clamp_val(val, 1, INT_MAX);
>   input->shunt_resistor = val;
> + }
>  
>   return 0;
>  }
> -- 
> 2.17.1
> 

[PATCH] hwmon: (ina3221) Clamp shunt resistor value from DT

[Nicolin Chen]

The input->shunt_resistor is int type while the value from DT is
unsigned int. Meanwhile, a divide-by-zero error would happen if
the value is 0. So this patch just simply clamps the value.

Signed-off-by: Nicolin Chen 
---
 drivers/hwmon/ina3221.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index c3a497aed345..ce8f0a8c4982 100644
--- a/drivers/hwmon/ina3221.c
+++ b/drivers/hwmon/ina3221.c
@@ -536,8 +536,10 @@ static int ina3221_probe_child_from_dt(struct device *dev,
of_property_read_string(child, "label", >label);
 
/* Overwrite default shunt resistor value optionally */
-   if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", ))
+   if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", )) {
+   val = clamp_val(val, 1, INT_MAX);
input->shunt_resistor = val;
+   }
 
return 0;
 }
-- 
2.17.1