Re: [PATCH] PM / domains: Kconfig: always enable PM_RUNTIME when genpd enabled

From: Rafael J. Wysocki
Date: Fri Nov 14 2014 - 17:20:25 EST


On Friday, November 14, 2014 09:36:17 AM Kevin Hilman wrote:
> Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> writes:
>
> > Hi Kevin,
> >
> > On Thu, Nov 13, 2014 at 11:28 PM, Kevin Hilman <khilman@xxxxxxxxxx> wrote:
> >> It makes little sense to use generic power domains without runtime PM.
> >
> > Does it?
> > It still powers down the PM domains on system suspend (at least on my
> > boards ;-)
>
> Sure, but your devices are also using runtime PM, so I'm not sure how
> does that change my statement above?

Questions here are (1) how many users will actually want to disable PM_RUNTIME
for systems using genpd (my sort of educated guess is "none") and (2) whether
or not we need to power up stuff dynamically during initialization on systems
using genpd (and several recent discussions indicate that the answer here is
"yes, we need to do that").

> >> Also, since the complexities of handling the !PM_RUNTIME case are
> >> causing more trouble and confusion than they're worth, let's simplify
> >> the world by making genpd always enable runtime PM.
> >
> > What do other people think?
>
> Yes, I'm curious also. This patch was supposed to be marked RFC.

I'm totally for making this change and I'm going to queue up this patch for
3.19, so if anyone sees a really good reason for not doing this, please let
me know what that reason is as soon as you can.

Rafael

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