Re: [PATCH 05/12] arm: omap3: am35x: Add PWROFF feature

Mark A. Greer
2012-04-11T23:11:39Z

On Wed, Apr 11, 2012 at 03:46:20PM -0700, Kevin Hilman wrote:
> Hi Mark,
>
> "Mark A. Greer" <mgreer@animalcreek.com> writes:
>
> > From: "Mark A. Greer" <mgreer@animalcreek.com>
> >
> > Typical OMAP3 SoCs have four power domain states: ON,
> > INACTIVE, RETENTION, and OFF. The am35x family of SoCs
> > has only two states: ON and INACTIVE. To distinguish which
> > set of states the current device has, add the 'OMAP3_HAS_PWROFF'
> > feature. When that feature/bit is set, the device supports the
> > RETENTION and OFF states; otherwise, it doesn't.
> >
> > Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
>
> Paul has mentioned this already, but the same applies here: We shouldn't
> be using SoC-global feature flag for this. We already have per-pwrdm
> flags that indicate what states a given powerdomain suports (see .pwrsts
> field.)
>
> Wherever we have blind writes to next powerstates that assume support
> for RET/OFF is present, those should probably use a helper function from
> the powerdomain code that checks if that state is even supported.

Okay, thanks Kevin.

> Jean's work on functional powerstates will probably help here if you
> really need to support INACTIVE. However, Paul may be right in that you
> might just start with supporing ON only, and validate that module-level
> wakups acutally work.

Yeah, I'm going to do that as soon as I catch up the emails. I thinking
more & more that Paul is right and that we should just scrap the INACTIVE
state and leave everything ON.

Mark
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