[PATCH v8 0/6] ACPI / processor_idle: Add ACPI v6.0 LPI support

Sudeep Holla sudeep.holla at arm.com
Fri Jul 8 04:04:40 PDT 2016



On 07/07/16 22:02, Rafael J. Wysocki wrote:
> On Thu, Jul 7, 2016 at 7:10 PM, Sudeep Holla <sudeep.holla at arm.com> wrote:
>> ACPI 6.0 introduced LPI(Low Power Idle) states that provides an alternate
>> method to describe processor idle states. It extends the specification
>> to allow the expression of idle states like C-states selectable by the
>> OSPM when a processor goes idle, but may affect more than one processor,
>> and may affect other system components.
>>
>> LPI extensions leverages the processor container device(again introduced
>> in ACPI 6.0) allowing to express which parts of the system are affected
>> by a given LPI state. It defines the local power states for each node
>> in a hierarchical processor topology. The OSPM can use _LPI object to
>> select a local power state for each level of processor hierarchy in the
>> system. They used to produce a composite power state request that is
>> presented to the platform by the OSPM.
>>
>> Since multiple processors affect the idle state for any non-leaf hierarchy
>> node, coordination of idle state requests between the processors is
>> required. ACPI supports two different coordination schemes: Platform
>> coordinated and  OS initiated.
>>
>> This series aims at providing basic and initial support for platform
>> coordinated LPI states.
>>
>> v7[7]->v8:
>>          - Replaced HAVE_GENERIC_CPUIDLE_ENTER with CPU_IDLE_ENTER_WRAPPED
>>            macro, which is more cleaner and definately less confusing :)
>>            (Thanks to Rafael for the suggestion)
>
> Patches [3-6/6] definitely look a lot cleaner to me now. :-)
>
> That said, the name of the macro I suggested was just an example, so
> if people don't like this one, it'd be fine to change it as far as I'm
> concerned.
>

I can think of addition to indicate it's pm notifiers wrapper.
i.e. CPU_IDLE_ENTER_PM_NOTIFIERS_WRAPPED. Is it too long ? I am happy
with the way it is too.

-- 
Regards,
Sudeep



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