Re: [PATCH 2/2] hwmon: iio: Add labels from IIO channels

[Sean Anderson <sean.anderson@linux.dev>]

On 6/21/24 11:08, Guenter Roeck wrote:
> On 6/20/24 14:13, Sean Anderson wrote:
>> Add labels from IIO channels to our channels. This allows userspace to
>> display more meaningful names instead of "in0" or "temp5".
>>
>> Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
>> ---
>>
>>   drivers/hwmon/iio_hwmon.c | 33 ++++++++++++++++++++++++++++++---
>>   1 file changed, 30 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/hwmon/iio_hwmon.c b/drivers/hwmon/iio_hwmon.c
>> index 4c8a80847891..588b64c18e63 100644
>> --- a/drivers/hwmon/iio_hwmon.c
>> +++ b/drivers/hwmon/iio_hwmon.c
>> @@ -33,6 +33,17 @@ struct iio_hwmon_state {
>>       struct attribute **attrs;
>>   };
>>   +static ssize_t iio_hwmon_read_label(struct device *dev,
>> +                  struct device_attribute *attr,
>> +                  char *buf)
>> +{
>> +    struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
>> +    struct iio_hwmon_state *state = dev_get_drvdata(dev);
>> +    struct iio_channel *chan = &state->channels[sattr->index];
>> +
>> +    return iio_read_channel_label(chan, buf);
> 
> This can return -EINVAL if there is no label. Since the label attribute
> is created unconditionally, every affected system would end up with
> lots of error messages when running the "sensors" command.
> This is not acceptable.

The sensors command gracefully handles this. There are no errors, and the label is unused.

--Sean