Subject: [PATCH] ARM: OMAP4: PM: Avoid expensive cpu_suspend() path for all CPU power states except off

From: [email-masked] (Kevin Hilman)
Date: Tue, 12 Feb 2013 07:18:14 -0800

Santosh Shilimkar <[email-masked]> writes:

> On Saturday 09 February 2013 02:49 AM, Kevin Hilman wrote:
>> Santosh Shilimkar <[email-masked]> writes:
>>
>>> Current CPU PM code code make use of common cpu_suspend() path for all the
>>> CPU power states which is not optimal. In fact cpu_suspend() path is needed
>>> only when we put CPU power domain to off state where the CPU context is lost.
>>>
>>> Update the code accordingly so that the expensive cpu_suspend() path
>>> can be avoided for the shallow CPU power states like CPU PD INA/CSWR.
>>>
>>> Cc: Kevin Hilman <[email-masked]>
>>>
>>> Reported-by: Richard Woodruff <[email-masked]>
>>> Signed-off-by: Santosh Shilimkar <[email-masked]>
>>
>> Looks OK at first glance, but are you sure this is right for the
>> various ways both clusters might idle using coupled CPUidle?
>>
> Yes it is perfectly safe from all C-states. This patch has been part of
> the OMAP4/OMAP5 product port for some time. I forgot to send it upstream
> some how :(
>
>> Some description of the testing would be helpful here.
>>
> Sorry. Should have mentioned it in first place.
> Patch is being tested on OMAP4430 (idle/suspend) and OMAP5 with
> few out of tree patches.

OK, please update changelog with a brief description of how it was
tested, and on which platforms.

Thanks,

Kevin