[PATCH 1/2] ARM: OMAP3: PM: remove superfluous calls to pwrdm_clear_all_prev_pwrst()

Shilimkar, Santosh
2012-01-31T08:37:28Z

On Tue, Jan 31, 2012 at 1:19 PM, Paul Walmsley <paul@pwsan.com> wrote:
> On Tue, 31 Jan 2012, Shilimkar, Santosh wrote:
>
>> A week back I was discussing with Benoit and Tony about having some
>> infrastructure like "unused clocks" so that we can shutdown those
>> modules, and if possible some power domains. That way they get
>> removed at one single place and they the power domain calls
>> need not iterate over the once which are no longer needed.
>
> Sure, if you have some ideas, that sounds promising. ?I'd assume the main
> performance issues would be related to global PRCM register reads, rather
> than raw CPU cycles. ?So that's probably where it would make sense to
> focus the effort.
>
I fully agree that PRCM register read time is the main issue.
Would discuss this with Benoit and Rajendra bit more on what we
can be done.

> We should also be able to optimize out a fair number of the powerdomain
> register reads if we cache them in the struct powerdomain. ?The current
> powerstate and next powerstate seem to be hit a lot, and those should both
> be cacheable. ?Will probably do some of this as part of the functional
> powerstate code.
>
PD register caching seems to be a good optimization.

Regards
Santosh