Re: possible showstopper: kbdmux hangs -current

On 7/27/07, Dmitry Morozovsky <marck_at_rinet.ru> wrote:
> Hi there,
>
> on some of my mobos -current hangs early (when starning init) if kbdmux is
> included in kernel (both on i386 and amd64); this seems to be some race, as
> hangs are not 100% reproducible. What info should I provide to debug?

the usual suspects are

1) while (KBDMUX_CHECK_CHAR(kbd)) { ... } loop in kbdmux_kbd_event().
could you please try to put some debug printf's into it and make sure
it does not stuck there.

2) callout. kbdmux callout initialized as non mp-safe to make sure
giant is held.

3) task queue. kbdmux(4) uses taskqueue_swi_giant.

you might want to try uncomment section at line 81 in kbdmux.c. this
should add private lock for kbdmux(4). not sure it will work though -
many things has changed since i tried it.

> I'm using only PS2 keyboards, and have no other format keyboards handy;
> however, I can obtain USB keyb if needed.

are you using ps/2 mouse? if so, try to disconnect it and see if this helps.

as you said, you could try to use usb keyboard instead of ps/2.

thanks,
max