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

Stewart Smith stewart at linux.vnet.ibm.com
Wed Mar 22 08:30:42 AEDT 2017


Cédric Le Goater <clg at kaod.org> writes:
> 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.

Yeah, I'm thinking the core sensors is where to go.

Centaur sensors aren't necessarily going to be there in P9 though,
right? Or do we have the same sensors but on die?

-- 
Stewart Smith
OPAL Architect, IBM.



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