Driver causes xorg to incorrectly load cmt for other devices

[rhomel]

I recently upgraded my Linux Ubuntu install from 15.04 to 16.04 on an Acer c720p chromebook and found out one of the configurations was causing xorg to attempt to load the cmt driver for my Logitech M510 mouse. The workaround solution was to remove the InputClass section in 20-mouse.conf and restart. Details below.

/var/log/Xorg.0.log

[    10.923] (II) config/udev: Adding input device Logitech M510 (/dev/input/event7)
[    10.923] (**) Logitech M510: Applying InputClass "evdev pointer catchall"
[    10.923] (**) Logitech M510: Applying InputClass "generic mouse for Chromium OS"
[    10.923] (II) LoadModule: "cmt"
[    10.923] (II) Loading /usr/lib/xorg/modules/input/cmt_drv.so
[    10.932] (II) Module cmt: vendor="X.Org Foundation"
[    10.932]    compiled for 1.17.1, module version = 0.0.1
[    10.932]    Module class: X.Org XInput Driver
[    10.932]    ABI class: X.Org XInput driver, version 21.0
[    10.932] (EE) module ABI major version (21) doesn't match the server's version (22)
[    10.932] (II) UnloadModule: "cmt"
[    10.932] (II) Unloading cmt
[    10.932] (EE) Failed to load module "cmt" (module requirement mismatch, 0)
[    10.932] (EE) No input driver matching `cmt'
[    10.933] (II) config/udev: Adding input device Logitech M510 (/dev/input/mouse0)
[    10.933] (II) No input driver specified, ignoring this device.
[    10.933] (II) This device may have been added with another device file.

Solution is to comment out the following block in /usr/share/X11/xorg.conf.d/20-mouse.conf :

#Section "InputClass"
#    Identifier      "generic mouse for Chromium OS"
#    MatchIsPointer  "on"
#    MatchDevicePath "/dev/input/event*"
#    Driver          "cmt"
#    Option          "AccelerationProfile" "-1"
#    Option          "AccelerationScheme" "none"
#    Option          "AccelerationNumerator" "0"
#    Option          "AccelerationDenominator" "1"
#    Option          "AccelerationThreshold" "0"
#    Option          "Mouse Accel Curves" "1"
#    Option          "Mouse Scroll Curves" "1"
#    Option          "Point X Out Scale" "0.3"  
#    Option          "Point Y Out Scale" "0.3"
#
#    # CMT devices potentially process keyboard events
#    Option          "XkbModel" "pc"
#    Option          "XkbLayout" "us"
#
#    Option          "Accel Min dt" "0.0001"
#EndSection