kbdmux(4) freezing the system

Maksim Yevmenkin maksim.yevmenkin at gmail.com
Thu Aug 25 21:12:05 GMT 2005


> I tried using kbdmux(4) and after a lot of fiddling with rc.d/syscons
> and devd.conf I worked out a solution that more or less works for me.
> Sadly, in the two days I've been using kdbmux(4) I had my box freeze
> suddenly several times. This almost always happened when I was using the
> touchpad (and no other keyboard present). I have no panic strings or
> dumps or whatsoever, since it always happened in X and somehow I can't
> reproduce how to get a DDB prompt via Firewire.

unfortunately its true. i was able to narrow it down on my system to
ps/2 mouse and/or keyboard. basically if i use ps/2 mouse (and
probably ps/2 keyboard) with kbdmux(4) i have system freeze. the
solution that works for me is to _not_ use ps/2 mouse.

you should also know that there is a keyboard state synchronization
problem with kbdmux(4) (seems to be related to control/shift/alt keys)
that i can reproduce, but still can not fix :(

> So, are there any users of kbdmux out there? Are there any known
> problems with system freezes? (I'm running RELENG_6 btw).

i did not get much of a feedback, so i assume not many people are using it.
> I stopped using kbdmux(4) for now and not another freeze occurred, so it
> strongly points to kbdmux being the culprit.

yes, kbdmux(4) is definitely involved here. this is a high priority
item on my todo list and as soon as i get enough free time i will look
into this again.


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