[Skiboot] [PATCH 0/3] P9 core dts support

[Cédric Le Goater]

On 03/17/2017 12:51 AM, Stewart Smith wrote:
> Cédric Le Goater <clg at kaod.org> writes:
>> On 03/16/2017 08:07 AM, Stewart Smith wrote:
>>> Cédric Le Goater <clg at kaod.org> writes:
>>>> On 02/23/2017 07:04 PM, Rob Lippert wrote:
>>>>> On Thu, Feb 23, 2017 at 5:01 AM, Cédric Le Goater <clg at kaod.org> wrote:
>>>>>> Rob,
>>>>>>
>>>>>> Some update,
>>>>>>
>>>>>>>> Cedric, any update on getting the P9 DTS sensors to work with skiboot?
>>>>>>>>
>>>>>>>> We have not tested yet since I was waiting for confirmation on your side.
>>>>>>>
>>>>>>> The skiboot framework is in place (with this patch) and the kernel
>>>>>>> module is creating the hwmon sysfs entries. I need to dig a little
>>>>>>> further to see why we read zeroes on the core DTS as I did not see
>>>>>>> any XSCOM errors.
>>>>>>>
>>>>>>> I will try on another system next week.
>>>>>>
>>>>>> So it seems that the VPD in the OpenPOWER firmware misses calibration
>>>>>> settings for the core thermal latches. Those settings being zero
>>>>>> by default, the result of the equation is zero for the DTS.
>>>>>>
>>>>>> I am working on getting these included in the VPD now.
>>>>>
>>>>> OK, will we need a VPD update for the CPU (which I don't think we can
>>>>> do) or just the planar VPD?
>>>>
>>>> With a relatively recent firmware, I got it working on a 
>>>> witherspoon:
>>>>
>>>>
>>>> root at w39l:~#  cat  /sys/class/hwmon/hwmon0/temp*
>>>> 40000
>>>> Core 0
>>>> 54000
>>>> Core 4
>>>> 52000
>>>> Core 8
>>>> 49000
>>>> Core 12
>>>> 49000
>>>> Core 16
>>>> 50000
>>>> Core 20
>>>>
>>>> root at w39l:~# sensors
>>>> ibmpowernv-isa-0000
>>>> Adapter: ISA adapter
>>>> Core 0:       +40.0°C  
>>>> Core 4:       +54.0°C  
>>>> Core 8:       +53.0°C  
>>>> Core 12:      +50.0°C  
>>>> Core 16:      +50.0°C  
>>>> Core 20:      +50.0°C  
>>>>
>>>> Rob, I still need to check what exactly has changed in hostboot or if
>>>> I was testing on a really early version of the cores.  Anyhow, it is 
>>>> safe to use. 
>>>>
>>>>
>>>> Stewart, I think you can merge now.
>>>
>>> Thanks. It seemed to work on the zz I tried (at least if the test cases
>>> are correct... 
>>
>> I gave it a try on a Romulus as well.
>>
>>> might want to check with Pridhiviraj that we've got sufficient testing 
>>> in op-test-framework).
>>
>> This looks correct :
>>
>> https://github.com/open-power/op-test-framework/blob/master/testcases/OpTestSensors.py
>>
>> May be we should look for specific OPAL sensors because if there is an
>> adapter exposing sensors on the system, the test will return success 
>> even if there are no OPAL.
> 
> Yeah, I was thinking that.
> 
> At this point, we *know* that we have some sensors inside the chip, and
> probably a relatively known set (or at least somewhat computable?), so
> yeah, we probably should check explicitly for them.
> 
> I wonder if the list of sensors is constant enough to do what we do for
> PCI devices, have a per-machine file of sensors that we detected to
> ensure we continue to detect the correct ones.

We always have cores. So we could track these sensors. OpenPOWER systems
also expose the Centaur sensors.

C.