crie um arquivo chamado .xessionrc e coloque este comando nele:
#get the device ID for the trackpad. We know it contains the string "TPPS"
ibm_trackpad_id=$(xinput | grep 'TPPS' | cut -d"=" -f2 | cut -f1)
echo $ibm_trackpad_id > ~/temp/ibm_trackpad_id
#set desired params for trackpoint
xinput set-prop $ibm_trackpad_id "Evdev Wheel Emulation" 1
xinput set-prop $ibm_trackpad_id "Evdev Wheel Emulation Button" 2
xinput set-prop $ibm_trackpad_id "Evdev Wheel Emulation Timeout" 200
xinput set-prop $ibm_trackpad_id "Evdev Wheel Emulation Axes" 7 6 5 4
xinput set-prop $ibm_trackpad_id "Device Accel Constant Deceleration" 0.10