Re: [PATCH v9 0/7] ACPI / processor_idle: Add ACPI v6.0 LPI support
From: Rafael J. Wysocki
Date: Tue Jul 12 2016 - 08:04:54 EST
On Tuesday, July 12, 2016 12:42:06 PM Sudeep Holla wrote:
> On 08/07/16 18:07, Sudeep Holla 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.
> I was hoping to get this in v4.8 now that merge window is
> delayed/extended if you have no further comments on this series.
I'll get to it in the next couple of days. If it looks all good and there are
no comments, I'll queue it up.