Subject: [v4 PATCH 0/5]: cpuidle/POWER (REDISIGN): Introducing cpuidle to POWER.

From: Arun R Bharadwaj <[email-masked]>
Date: Tue, 1 Sep 2009 17:07:04 +0530

Hi,

******** This is an RFC, not for inclusion **********

This patchset introduces cpuidle infrastructure to POWER, prototyping
for pseries and currently in the process of porting to x86 and hence
will *not* build on x86/other POWER platforms.

This is to get initial comments on the redesign of my earlier implementation
which can be found at http://lkml.org/lkml/2009/8/27/124

Major changes from last iteration:
----------------------------------

* Cleanup drivers/cpuidle/cpuidle.c
	Currently, the cpuidle implementation has weakness in the
	framework where an exported pm_idle function pointer is
	manipulated by various subsystem. The proposed framework has
	a registration architecture to cleanly add and remove new idle
	routines from different subsystems.

* Introduce [un]register_idle_function() routines
        Implement a LIFO based approach for registering architecture
        dependent idle routines.

* Sample implementation of register_idle_function for pSeries

TODO:
-----

* Extend this prototype to cover x86 and other archs that use cpuidle.
        Currently, in x86, the cpu_idle() idle loop doesn't have a
        default idle loop to fall back to if pm_idle is NULL, unlike
        the corresponding implementation in pseries, where
        ppc_md.power_save can be NULL and there is a fallback.
        So we need to create a similar fork in cpu_idle() idle loop of
        x86.

Patches included in this series:
--------------------------------

1/5 - Cleanup drivers/cpuidle/cpuidle.c
2/5 - Implement routines to register and unregister idle function.
3/5 - Incorporate registering of idle loop for pSeries.
4/5 - Add Kconfig entry to enable cpuidle for POWER.
5/5 - Implement pSeries processor idle module.

Any comments on the design is welcome.

--arun