Re: [PATCH] create CONFIG_SUSPEND_UP_POSSIBLE

[Pavel Machek <pavel@ucw.cz>]

On Fri 2007-08-03 15:23:19, Len Brown wrote:
> On Tuesday 31 July 2007 02:38, Pavel Machek wrote:
> > Hi!
> > 
> > > Without this change, it is possible to build CONFIG_HIBERNATE
> > > on all !SMP architectures, but not necessarily their SMP versions.
> > 
> > Did you want to say "CONFIG_SUSPEND"?
> 
> Yes.
> 
> > > I don't know for sure if the architecture list under SUSPEND_UP_POSSIBLE
> > > is correct.  For now it simply matches the list for
> > > SUSPEND_SMP_POSSIBLE.
> > 
> > I do not think it is.
> > 
> > > Signed-off-by: Len Brown <len.brown@intel.com>
> > > ---
> > >  Kconfig |    7 ++++++-
> > >  1 file changed, 6 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
> > > index 412859f..ccf6576 100644
> > > --- a/kernel/power/Kconfig
> > > +++ b/kernel/power/Kconfig
> > > @@ -72,6 +72,11 @@ config PM_TRACE
> > >  	CAUTION: this option will cause your machine's real-time clock to be
> > >  	set to an invalid time after a resume.
> > >  
> > > +config SUSPEND_UP_POSSIBLE
> > > +	bool
> > > +	depends on (X86 && !X86_VOYAGER) || (PPC64 && (PPC_PSERIES ||
> > 
> > At least ARM can do suspend, too... probably others. I was under
> > impression that SUSPEND is "supported" by all the architectures, just
> > some of them veto it at runtime (using pm_ops or how was it renamed).
> 
> The reason this entire thread started is because Linus, Jeff and others
> said that they didn't want code magically compiled into their kernel
> that they did not explicitly ask for -- even if the savings were small
> and that kernel was already something rather beefy, such as ACPI+SMP.
> 
> The current code is simply broken, because it allows SUSPEND
> on IA64 if UP, but not on SMP.  It should really be neither.

Actually, it should be both, AFAICT. Suspend infrastructure should be
there, just returing -EINVAL... that's how it worked in 2.6.22 IIRC.

									Pavel
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