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

Kevin Hilman khilman at linaro.org
Tue Feb 12 10:18:14 EST 2013


Santosh Shilimkar <santosh.shilimkar at ti.com> writes:

> On Saturday 09 February 2013 02:49 AM, Kevin Hilman wrote:
>> Santosh Shilimkar <santosh.shilimkar at ti.com> 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 <khilman at deeprootsystems.com>
>>>
>>> Reported-by: Richard Woodruff <r-woodruff2 at ti.com>
>>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
>>
>> 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



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