IBM T42 freezes when going to sleep under X11

[Jacques Garrigue]

From: George Hartzell <hartzell at kestrel.alerce.com>

> Jacques Garrigue writes:
>  > From: Jacques Garrigue <garrigue at math.nagoya-u.ac.jp>
>  > > I've got a strange problem with my IBM T42 / Radeon M10 setup.
>  > > 
>  > > When using the 6.0-RELEASE kernel (including GENERIC), I cannot go to
>  > > sleep when X11 is running: the machine freezes, display still on. I
>  > > tried disabling DRI, but this does not seem to be the problem: I have
>  > > no DRM anyway.
>  > > 
>  > > On the other hand, everything works fines with a 6.0-RC1 kernel.
>  > > Was there a big change in between, such that I need to change my
>  > > configuration?
>  > 
>  > I finally found the cause of my problems: there has been changes in
>  > the em driver (Gb ethernet), such that the machine freezes when trying
>  > to switch automatically from the X11 VT to the system console, before
>  > going to sleep. The interaction is surprising, but clearly the problem
>  > disappears when I remove "device em" from the kernel configuration,
>  > and it reappears when I do "kldload if_em". Since I'm using only ath
>  > (wireless) anyway, this is fine with me...
> 
> I don't seem to have any problem with my T42p using a kernel compiled
> on 11/29 11:21
> 
> My copy of if_em.c is:
> 
> /*$FreeBSD: src/sys/dev/em/if_em.c,v 1.65.2.8 2005/11/25 14:11:59 glebius Exp $*/

The very same version I could reproduce the bug with...

I suppose the cause is a complex interaction.
For instance it only appears under X11.
So part of the reason might be the difference between the radeon M10
and the FIRE GL T2. Or the fact I'm simultaneously using
ath. Or anything else...
My point was just that the direct trigger was a change in em between
6.0-RC1 and 6.0-RELEASE. But if it cannot be reproduced on any other
machine, this is going to be difficult to track down.

By the way, I have another problem: if I set my display background to
an image (under KDE or xfce4), then the bottom half of the image gets
garbled after resume. Do you observer anything like that? Might this
be a sign of something wrong in the X11 driver? (I just use the
default Xorg)

Jacques Garrigue