usb/175731: detaching USB keyboard freezes other USB keyboards

Hans Petter Selasky hselasky at
Mon Feb 11 10:25:04 UTC 2013

On Thursday 07 February 2013 22:40:01 Hans Petter Selasky wrote:
> The following reply was made to PR usb/175731; it has been noted by GNATS.


You should look into HAL and xf86-input-keyboard ports. I don't have time to 
debug this currently.

To prevent KBD X11 driver unload by /usr/ports/x11-drivers/xf86-input-keyboard 
change this in the source code:

-    xf86AddInputDriver(&KBD, NULL, 0);
+    xf86AddInputDriver(&KBD, module, 0);
     return module;

The problem is deeper. When X11 sees that the keyboard is gone it 
issues some IOCTLs on /dev/console, like the keyboard MODE and then no more 
keys are received. See using ktrace on Xorg. This is a shared device receiving 
key-presses for all keyboards as far as I can see and it should only be 
programmed once. This is currently not handled.

Inside the file referenced below code is present to set "x11_driver" to "kbd". 
Probably changing this will affect the outcome too:


How to reproduce:

Plug two USB keyboards using a HAL enabled Xorg server. Unplug one keyboard. 
Input from the other keyboard disappears until some other keyboard device is 
plugged again!


More information about the freebsd-x11 mailing list