Re: community PM requirements/issues and PowerOP [Was: Re: So, what's the status on the recent patches here?]

David Brownell
2006-09-13T04:22:09Z

Hi Matt,

> From matt@nomadgs.com Mon Sep 11 14:56:58 2006
>
> Greg, Pavel, Dominik, Dave J and Dave B,
>
> I would like to get a plan in place for acceptance with the power
> management guys before we move this to lkml. I propose that we submit
> the current set of PowerOP patches plus final few changes (from Greg's
> comments and a Documentation/ file). The patches do not affect anyone
> else. The sysfs interface is optional. If necessary Eugeny and I will
> maintain userspace interface patches outside the mainline for now.
> Will any of the power management maintainers ACK this plan and then ACK
> the patches? If no one here is willing to ACK, then I don't see what
> will change by submitting to lkml.

The Linux-PM list booted me off itself for a while, and I just got
back on and haven't gotten through the backlog yet. Right now the
distinctions and relationships between any of the "recent patches"
and system-wide mechanisms like

- lowpower idle tasks;

- multiple run states ... cpufreq doing an inadequte subset,
even if you're only interested in CPUs;

- multiple sleep states ... /sys/power/state listing "standby"
and/or "mem" (kind of weak for embedded systems) and "disk"
(which is checkpoint/resume, not really sleep);

are not fully evident to me, so acking anything seems premature.
Plus there's an "ACPI way" to do so much of that, which doesn't
much help most non-x86 systems.

I thought I saw patches generalizing both sleep and run states
(separate patch sets!) ... plus a good comment from Greg that
a short (!) "elevator pitch" seemed to be lacking.

- Dave