Re: [PATCH] PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is selected (was: Re: [PATCH] PM / domains: Kconfig: always enable PM_RUNTIME when genpd enabled)

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Tuesday, November 18, 2014 09:34:11 AM Pavel Machek wrote:
> On Tue 2014-11-18 01:39:06, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > 
> > The number of and dependencies between high-level power management
> > Kconfig options make life much harder than necessary.  Several
> > conbinations of them have to be tested and supported, even though
> > some of those combinations are very rarely used in practice (it
> > they are used in practice at all).  Moreover, the fact that we
> > have separate independent Kconfig options for runtime PM and
> > system suspend is a serious obscacle for integration between
> > the two frameworks.
> > 
> > To overcome these difficulties, always select PM_RUNTIME if PM_SLEEP
> > is set.  Among other things, this will allow system suspend callbacks
> > provided by bus types and device drivers to rely on the runtime PM
> > framework regardless of the kernel configuration.
> 
> 3.18-rc5 still has:
> 
> config PM_RUNTIME
>         bool "Run-time PM core functionality"
>         depends on !IA64_HP_SIM
>         ---help---
> 
> So I assume this patch is against tree where PM_RUNTIME does not
> depend on anything?

Yes.

> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > ---
> > 
> > As a follow up.
> > 
> > Note that we won't need the patch making genpd select PM_RUNTIME with this,
> > because genpd already depends on PM.
> 
> Looking through the config file, there are more config options that
> should be stripped.
> 
> config SUSPEND_FREEZER
>         bool "Enable freezer for suspend to RAM/standby" \
> "Turning OFF this setting is NOT recommended! If in doubt, say Y."

Yeah, I'll gladly apply a patch removing this one. :-)

> config HIBERNATE_CALLBACKS
>        bool
> 
> ...can we just use CONFIG_HIBERNATE, instead?

We do, but in addition.

HIBERNATE_CALLBACKS is used by Xen IIRC and they don't want to build in the
whole hibernation image creation etc code (which they never use anyway).

Rafael