Subject: Re: [PATCH] net: dsa: set parent of hwmon device

From: Vivien Didelot <[email-masked]>
Date: Wed, 21 Jan 2015 11:26:59 -0500 (EST)

Hi Guenter, Florian,

>>> -               ds->hwmon_dev = hwmon_device_register_with_groups(NULL,
>>> +               ds->hwmon_dev = hwmon_device_register_with_groups(parent,
>>>                                         ds->hwmon_name, ds, dsa_hwmon_groups);
>>>                 if (IS_ERR(ds->hwmon_dev))
>>>                         ds->hwmon_dev = NULL;
>>
>> Looking into my old e-mail, turns out we did not add the parent
>> device because it affected the output of the "sensors" command, and
>> we wanted the device to be handled as 'virtual device' (which implies
>> no parent). That was an explicit part of the patch set (v2 of 'net:
>> dsa: Add support for reporting switch chip temperatures'), compared
>> to v1, which did set the parent device.

I don't know about the "sensors" output, but I found that convenient
from the sysfs side to have a hierarchy of sub-devices logically exposed
at the same place, i.e.:

	# ls /sys/devices/platform/dsa.0
	driver    hwmon    net    ...

>> I would suggest to keep the code as is.

> Maybe follow-up with a comment adding that above the call to
> hwmon_device_register_with_groups()? I suspect the intent is clear if
> you are deep into hwmon devices, but not necessarily for the reader ;)

Thanks,
-v