[PATCH v2 1/2] powerpc/powernv: Add poweroff (EPOW, DPO) events support for PowerNV platform

Vipin K Parashar vipin at linux.vnet.ibm.com
Thu May 14 06:17:04 AEST 2015

On 05/11/2015 12:19 PM, Michael Ellerman wrote:
> On Thu, 2015-05-07 at 15:00 +0530, Vipin K Parashar wrote:
>> This patch adds support for FSP EPOW (Early Power Off Warning) and
>> DPO (Delayed Power Off) events support for PowerNV platform.  EPOW events
>> are generated by SPCN/FSP due to various critical system conditions that
>> need system shutdown.  Few examples of these conditions are high ambient
>> temperature or system running on UPS power with low UPS battery. DPO event
>> is generated in response to admin initiated system shutdown request.
>> 	This patch enables host kernel on PowerNV platform to handle OPAL
>> notifications for these events and initiate system poweroff. Since EPOW
>> notifications are sent in advance of impending shutdown event and thus
>> this patch also adds functionality to wait for EPOW condition to return to
>> normal. Host allows MAX_POWEROFF_SYS_TIME (600 seconds) as system
>> poweroff time (time for host + guests shutdown) and waits for remaining
>> time for EPOW condition to return to normal. If EPOW condition doesn't
>> return to normal in calculated time it proceeds with graceful system
>> shutdown. For EPOW events with smaller timeouts values than
>> MAX_POWEROFF_SYS_TIME it proceeds with system shutdown without any wait
>> for EPOW condition to return to normal.
> Can I suggest an alternative design:
>   - when we recieve a DPO event call orderly_poweroff()
>   - when we recieve an EPOW event call orderly_poweroff()
> Thoughts?

Will make changes as per suggested design above and sent out patch.

> cheers

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