Re: [RFC][PATCH 0/2] PM / Sleep: Extended control of suspend/hibernate interfaces

[Richard Hughes]

NeilBrown <neilb <at> suse.de> writes:
> gnome-power-manager talks to upowerd over dbus to ask for a suspend.

Quite a few other desktops talk to upower, including XFCE, KDE and LXDE.
It's basically the only way on a modern desktop a user can put the
machine to sleep without becoming root.

> upowerd then runs /usr/sbin/pm-suspend.
> pm-suspend then runs all the script in /usr/lib/pm-utils/sleep.d/
> and the calls "do_suspend" which is defined in
> /usr/lib/pm-utils/pm-functions
> 
> Ugghh.. That is a very deep stack that is doing things the "wrong"
> way.
> i.e. it is structured about request to suspend rather than requests to
> stay awake.

Erm, that's what it was designed to do. UPower has never had any feature
requests to manage "stay-awake" functionality as upower is pretty much a
mechanism daemon, rather than a policy daemon. Certainly just writing to
/sys if /usr/lib/pm-utils/pm-functions isn't installed would be a very
sane patch to suggest, given that pm-suspend in Fedora 16 basically
doesn't do anything anymore.

UPower does have signals that tell userspace when a suspend is about to
happen, and when the computer has been resumed, and this is done using
DBus.

I think it would be a shame to have Yet Another Daemon and Yet Another
Protocol just for managing this stuff, when upower already has DBus and
tons of client support. I think adding a tiny DBus interface on upower
to manage the stay-awake functionality would make things much less
complicated and give us a common desktop / embedded story.

Richard.

(please cc me in any replies, not subscribed)


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