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

Stewart Smith stewart at linux.vnet.ibm.com
Fri Mar 17 10:51:12 AEDT 2017

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.

Stewart Smith
OPAL Architect, IBM.

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