kbdmux oddity ?

[Lena at lena.kiev.ua]

On Tue, May 09, 2006 at 05:01:30PM -0700, Pascal Hofstee wrote:

> Today i got to actually installing a kbdmux enabled kernel and came to
> the conclusion that even though keys like Capslock, Numlock and
> Scrolllock perform the functions they're supposed to do, the keyboard
> leds seem to arbitrarily decide wether or not they want to toggle
> on/off.
> 
> on console i noticed that usually after hitting e.g. caps lock a few
> times the leds decdide to "work with me again" and toggle on/off
> accordingly .. until i hit any actual textual input .. at which point
> the previous eratic behavior has resurfaced.
>
> Similar problems exist in X as well ... though seem to be even more
> eratic there.
> 
> Removing kbdmux from my kernel seems to restore normality again.

Emil Mikulic <emil at cs.rmit.edu.au> wrote:

> I'm seeing a similar (but different?) problem - I get an interrupt storm
> every time I hit Caps Lock or Num Lock, or flip VTs in text mode.  If
> XMMS is running, the music skips.
>
> Normally, if I'm hitting letter keys, I never see any irq1: atkbd0
> interrupts.  If I bounce on the Caps Lock, I can get it as high as
> 72/sec.
>
> Running top(1), I can get system time up to about 50% by pounding away
> at Caps Lock.  Normal typing doesn't affect the system time much, it
> fluctuates between 0% and 1%.
>
> This is with 7-CURRENT, GENERIC, on x86, from yesterday.  And it's on a
> Dell GX280 with a USB keyboard.  I've seen similar issues on a Dell
> Poweredge SC430, again with a USB keyboard.

> If I add hint.atkbd.0.disabled="1" to /boot/loader.conf,
> I no longer see this problem.

Maksim Yevmenkin <maksim.yevmenkin at savvis.net> wrote on May 10, 2006:

> i can not reproduce it here with dell latitude d610 laptop. i think, 
> that this maybe particular usb keyboard/bios fault. kbdmux(4) really 
> does not do anything except switching slave keyboards into "raw" mode 
> and pass all scancodes to the upper layers. it seems like kbdmux(4) 
> exposes all the little problems with low level keyboard drivers.
>
> again, i'm looking into this, but i do not have much time right now.

FreeBSD 6.1-RELEASE-p2, Abit BE6-II motherboard made in 2000 or 2001,
PS/2 keyboard, no USB keyboard. In console the Caps Lock key works,
but the Caps Lock LED doesn't lit up at all. In X the LED works OK.

Adding hint.kbdmux.0.disabled="1" to /boot/device.hints
made the Caps Lock LED to work in console again.

Lena