_ [comp] AllowEmptyInput

突然 X が固まったので再起動したら、キーボードとマウスが効かなくなった。仕方ないので poweroff で電源を切って Xorg.0.log を見てみると、

(==) ModulePath set to "/usr/lib/xorg/modules"
(II) Cannot locate a core pointer device.
(II) Cannot locate a core keyboard device.
(II) The server relies on HAL to provide the list of input devices.
        If no devices become available, reconfigure HAL or disable AllowEmptyInput.

なんだこれは。xorg.conf(5) を見て、/etc/X11/xorg.conf に

Section "ServerFlags"
        Option          "AllowEmptyInput"       "off"


(==) ModulePath set to "/usr/lib/xorg/modules"
(==) |-->Input Device "Configured Mouse"
(==) |-->Input Device "Generic Keyboard"
(==) No Layout section. Using the first mouse device.
(==) No Layout section. Using the first keyboard device.