Re: [linux-pm] suspend blockers & Android integration

From: Alan Stern
Date: Thu Jun 10 2010 - 10:39:58 EST

On Wed, 9 Jun 2010 david@xxxxxxx wrote:

> why could the suspend blocker process see all events, but the power
> manager process not see the events?
> have the userspace talk to the power manager the way it does to the
> suspend blocker now and what's the difference?
> effectivly think s/suspend blocker/power manager/ (with the power manager
> doing all the other things that are proposed instead of grabbing the
> wakelock), the difference should be hidden to the rest of userspace.
> what am I missing here?

The main difference is that with a userspace power manager, programs
have to tell the power manager whenever they open or close a
wakeup-capable device file (and send it a copy of the file descriptor).
With an in-kernel implementation these extra steps aren't needed,
because of course kernel drivers already know when their device files
are opened or closed.

Alan Stern

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at