One question is regarding of PECI driver.

One question is regarding of PECI driver.

[Derek Lin23]

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Hi team:

          We have a question for PECI driver, hope we can have some inputs and feedbacks.
          When PECI driver starts, it checks the availabilities for CPUs by the addresses defining in the device tree.
          But, when none of the CPUs are available, in our cases, CPUs are powered off, PECI driver responses with error messages of PECI clients and devices are not registered.
          Is it possible that PECI driver would listen the events for power-on? So, PECI driver would be reloaded and PECI clients and devices become available.
          Or, other thoughts and ideas?

Thank you,

Derek Lin

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Re: One question is regarding of PECI driver.

[Jae Hyun Yoo]

On 6/14/2019 2:24 AM, Derek Lin23 wrote:
> Hi team:
> 
>            We have a question for PECI driver, hope we can have some 
> inputs and feedbacks.
> 
>            When PECI driver starts, it checks the availabilities for 
> CPUs by the addresses defining in the device tree.

Yes, it's what PECI driver does.

>            But, when none of the CPUs are available, in our cases, CPUs 
> are powered off, PECI driver responses with error messages of PECI 
> clients and devices are not registered.

It's an expected result because PECI works only when the host CPU is
powered on.

>            Is it possible that PECI driver would listen the events for 
> power-on? So, PECI driver would be reloaded and PECI clients and devices 
> become available.

No. Instead, we are using CPU ping from user space and register PECI
clients at run time. Please check these services:

https://github.com/openbmc/dbus-sensors
https://github.com/openbmc/entity-manager

Thanks,
Jae

>            Or, other thoughts and ideas?
> 
> Thank you,
> 
> 
> Derek Lin
>