Re: Complete system freeze from virtual terminals / terminal emulators

[Florian Kulzer <florian.kulzer@icfo.es>]

On Sat, Apr 14, 2007 at 21:09:16 -0700, Pat Primate wrote:
> Florian Kulzer wrote earlier:

[...]

> > It looks like your X setup is OK as far as the graphics card is
> > concerned (see my remarks below). Maybe the problem is in some weird way
> > related to the pcspkr module which controls the system bell. You could
> > try to (un)load the module and see if that makes any difference. The
> > whole thing might be a very rare coincidence of several factors;
> > tracking it down might be difficult and not really worth it.
> >
> > [...]
> 
> Brilliant Florian, the problem does seem to be the pcspkr module. I
> modprobe -r pcspkr and the terminal works fine, then I modprobe pcspkr and
> everything freezes again. So I suppose all I have to do is blacklist the
> pcspkr module or something like that and my problems should be over.
> 
> Should I file a bug report for this with the kernel team then??

I would first test if the pcspkr module works (beeps) on the TTYs. This
bug could very well be somewhere in KDE (or X) and the absence of the
pcspkr module might "fix" things only because it leads to KDE/X skipping
some buggy code.

You can check "dmesg | grep -i speaker" for clues while playing around
with the module. It would be especially interesting to see if the magic
switch X->TTY->X changes anything in /dev/input. (Don't ask me why the
device node of the speaker is generated in "input".)

Anyway, if all else fails you can simply use

echo "blacklist pcspkr" > /etc/modprobe.d/pcspkr

to blacklist the pcspkr module during boot.

-- 
Regards,
          Florian