Subject: Re: Call for testing: ACPI standby/suspend support
To: Nathan J. Williams <>
From: Steven M. Bellovin <>
List: tech-kern
Date: 03/09/2006 13:09:04
On 09 Mar 2006 13:02:27 -0500
"Nathan J. Williams" <> wrote:

> "Jared D. McNeill" <> writes:
> > > With "apm -d -z", the same errors flash by on the console, and then it
> > > does go into a low-power mode; the display goes off, I can hear the
> > > disk spin down, and the wireless card turns off. When I press the
> > > power button, the same mutex error occurs, but it does power back up
> > > reasonably (I haven't tested that all devices work, but the disk,
> > > shell, and console, at least, come back).
> > >
> > > So those errors might not be the real problem if they happen in both
> > > -S and -z, but -z seems to kind-of work.
> > 
> > Great to hear, thanks!!!
> Sure thing.
> One other oddity: when I *resume* from suspending, the laptop starts
> blinking a suspend indicator (a small moon-shaped LED), and when I
> suspend again, it turns off. This seems slightly backwards, but I
> don't know what layer is responsible for it.

I wonder if that's related to the mutex.  A blinking crescent is supposed to indicate that it's in the process of suspending.  At a wild guess, there was some code that should have been entered that would turn it on *and* grab the mutex.

		--Steven M. Bellovin,