PSU Sensors - Associations

[James Feist]

On 10/23/19 10:56 AM, Patrick Venture wrote:
> On Wed, Oct 23, 2019 at 10:54 AM James Feist
> <james.feist at linux.intel.com> wrote:
>>
>> On 10/23/19 10:52 AM, Patrick Venture wrote:
>>> On Wed, Oct 23, 2019 at 10:50 AM James Feist
>>> <james.feist at linux.intel.com> wrote:
>>>>
>>>> On 10/23/19 10:37 AM, Patrick Venture wrote:
>>>>> So, I flipped the association interface addition and the property
>>>>> initialization to match other sensors, and then it started working.  I
>>>>> was curious if you had any suggestions on how to find the matching
>>>>> sensor given the paths, for instance:
>>>>>
>>>>> busctl get-property xyz.openbmc_project.PSUSensor
>>>>> /xyz/openbmc_project/sensors/temperature/alt2_Temperature
>>>>> xyz.openbmc_project.Association.Definitions Associations
>>>>> a(sss) 1 "chassis" "all_sensors"
>>>>> "/xyz/openbmc_project/inventory/system/board/Altie"
>>>>>
>>>>> busctl tree --no-pager xyz.openbmc_project.EntityManager|grep Altie
>>>>>              |-/xyz/openbmc_project/inventory/system/board/Altie
>>>>>              | |-/xyz/openbmc_project/inventory/system/board/Altie/al_temp_0
>>>>>              | |-/xyz/openbmc_project/inventory/system/board/Altie/al_temp_1
>>>>>              | |-/xyz/openbmc_project/inventory/system/board/Altie/al_temp_2
>>>>>              | `-/xyz/openbmc_project/inventory/system/board/Altie/alt1
>>>>>
>>>>> No alt2 -- so how do I know this?  I can walk every subordinate object
>>>>> to find the name match, but I was curious if you had a faster idea?
>>>>
>>>> So for the associations you should generally not look at the definition,
>>>> the definition is primarily for the mapper. You should be looking in the
>>>> mapper for the association that matches the sensor name that you care
>>>> about and it should point back to the configuration. If there are not
>>>> associations for each of the sub-sensors, there should be.
> 
> I took a look at the ObjectMapper interface you mentioned, and it just
> points to the Board, not the individual sensor from the board.
> 
>>>
>>> I must have looked at the wrong entry there because I didn't see
>>> anything pointing back to the sensor config entry, but just the sensor
>>> itself.  I'll take a look now, the PSU sensor naming issue is
>>> identical to the one if there is just another name available or the
>>> Pwm case.
>>
>> Ah you're right, I don't that that is implemented. Should we create a
>> new association for this? It seems useful.
> 
> Not that I don't love hearing that I'm right, but in this case I would
> have rather been wrong and there been a magic bullet in place that I
> had overlooked.
> 
> I think all of my association mapping woes would immediately go away
> if every sensor pointed to the configuration dbus object that brought
> it to life.

My original argument was to have the association to point to the 
configuration item, but I got overruled when trying to add it to bmcweb, 
as bmcweb cares what 'chassis' an item is in. I would have preferred 
pointing to the item that brought it to life, but then to find the 
chassis you need to go up one element in the path. That being said, it 
would be a small change to support both.


> 
>>
>>>>
>>>>>
>>>>> Thanks,
>>>>> Patrick
>>>>>