Re: CVS commit: src/etc/powerd/scripts

[Jukka Ruohonen <jruohonen%iki.fi@localhost>]

On Fri, Dec 31, 2010 at 12:51:24PM -0600, David Young wrote:
> IMO, we should put the system to sleep by sending a
> power-saving/wakeup-latency goal and a set of waking events (e.g.,
> keystroke, mouse movement, LAN activity) to the root device_t using
> drvctl.  To put any smaller set of devices to sleep, send the goal &
> wake events to some subtree.
>
> FWIW, the sleep states that ACPI names are not sufficient even to
> describe all of the potential sleep states of ACPI hardware.  I have a
> laptop that's perfectly capable of an "S3-like" sleep, but the ACPI BIOS
> doesn't support S3, and the HDD is not formatted properly for the S4
> sleep.

I would still make the distinction between "system sleep" and "device sleep".
It seems to me that you describe above the latter. In the former you still
need to call the machine-dependent suspend-sequences at some point.

There is nothing quite like ACPI when it comes to jargon. The actual device
power states are represented as "D-states", which range from D0 ("fully on")
to D3 ("fully off"). If I recall correctly, the same abstraction is used in
the USB or PCI specifications. As I've noted before, we lack a representation
for this in device_t.

- Jukka.