Re: Attempted summary of suspend-blockers LKML thread

[david]

On Thu, 5 Aug 2010, Rafael J. Wysocki wrote:

> On Thursday, August 05, 2010, david@xxxxxxx wrote:
> > On Wed, 4 Aug 2010, Rafael J. Wysocki wrote:
> >
> > > Subject: Re: Attempted summary of suspend-blockers LKML thread
> > >
> > > On Wednesday, August 04, 2010, david@xxxxxxx wrote:
> > > > On Wed, 4 Aug 2010, Rafael J. Wysocki wrote:
> > > > > In the suspend case, when you have frozen all applications, you can
> > > > > sequentially disable all interrupts except for a few selected ("wakeup") ones
> > > > > in a safe way.   By disabling them, you ensure that the CPU will only be
> > > > > "revived" by a limited set of events and that allows the system to stay
> > > > > low-power for extended time intervals.
> > > >
> > > > the benifit of this will depend on what wakeups you are able to avoid by
> > > > putting the hardware to sleep. Depending on the hardware, this may be not
> > > > matter that much.
> > >
> > > That's correct, but evidently it does make a difference with the hardware
> > > Android commonly runs on.
> >
> > Ok, but is there a way to put some of this to sleep without involving a
> > full suspend?
>
> Technically, maybe, but we have no generic infrastructure in the kernel for that.
> There may be SoC-specific implementations, but nothing general enough.

well, I know that we have specific cases of this (drive spin-down, cpu 
speed, display backlight for a few examples), is it worth trying to define 
a generic way to do this sort of thing? or should it be left as a 
per-device thing (with per-device knobs to control it)

I thought I had seen discussion on how to define such a generic power 
management interface, and I thought the results had been acceptable.


David Lang
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/