Re: [PATCH v5 2/5] ACPI / processor_idle: Add support for Low Power Idle(LPI) states

From: Sudeep Holla
Date: Tue Jun 14 2016 - 10:26:10 EST




On 13/06/16 22:05, Rafael J. Wysocki wrote:
On Friday, June 10, 2016 06:38:01 PM Sudeep Holla wrote:
Hi Rafael,

Hi,

On 11/05/16 16:37, Sudeep Holla wrote:
ACPI 6.0 introduced an optional object _LPI that provides an alternate
method to describe Low Power Idle states. 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 patch adds initial support for Platform coordination scheme of LPI.


I have added support for autopromote states(basically skip flattening or
creating composite state). I have also fixed the bug discussed in this
thread with Prashant. Do you have any other feedback on this version
that I incorporate before posting next version.

I'd really preferred it if you posted the next version without waiting for
my feedback to the previous one (as the feedback may not be relevant any
more among other things).


Sure, will do that soon.

--
Regards,
Sudeep