Re: [RFC] sleepy linux

[Oliver Neukum <oliver@neukum.org>]

Am Mittwoch, 26. Dezember 2007 21:32:58 schrieb Pavel Machek:
 
> ... I also don't need to call any suspend() routines, because all the
> drivers are already suspended, right?

Well, you have a number of devices which cannot do runtime pm.
They can do suspend/resume with the whole system. For them these
operations mean saving/restoring state.
So for these devices implementing autosuspend makes no sense.
They would sensibly do only idle/busy detection.
 
> And yes, I want device activity to prevent s2ram. If user is burning
> CD, machine should not sleep. If user is actively typing, machine

In these cases the devices involved should report themselves busy,
shouldn't they?

> should not sleep. My vision is: screen saver tells kernel keyboard
> need not be very responsive, at that point keyboard driver can
> autosuspend the keyboard, and if that was the last device, whole
> system sleeps.

We lack a notion of telling devices that they are opened only for
detecting wakeups. Currently a driver has to assume that an opened
device has to be fully functional.

	Regards
		Oliver