I have the main AT keyboard and an additional USB keyboard that is implemented as a side-effect of mouse.
Disconnecting the mouse (with included in it keyboard) causes AT keyboard to stop functioning. This is because HAL-support code in xorg causes it to unload the keyboard driver, even though another keyboard is still attached. (see stack below).
I suggest Xorg should only disable the keyboard driver when the last keyboard is disconnected. HAL interface is able to find all keyboards attached.
Stack of device deletion request:
This problem persists as of May 18 2014 in the following environment
X.Org X Server 1.12.4
Release Date: 2012-08-27
X Protocol Version 11, Revision 0
Build Operating System: FreeBSD 10.0-RELEASE-p6 amd64
Current Operating System: FreeBSD host 10.0-RELEASE-p11 FreeBSD 10.0-RELEASE-p11 #0: Wed May 14 14:03:59 UTC 2014 firstname.lastname@example.org:/usr/obj/usr/src/sys/GENERIC amd64
Build Date: 05 May 2014 05:42:01PM
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This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.
You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/xorg/driver/xf86-input-keyboard/issues/12.