Why do disabled input devices still work?

Question

In Ubuntu 16.04 I can disable my keyboard using xinput and still type:

$ xinput disable 12
$ xinput list-props 12
Device 'Corsair Corsair K70 RGB Gaming Keyboard':
    Device Enabled (133):   0
    Coordinate Transformation Matrix (135): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
    Device Product ID (251):    6940, 6931
    Device Node (252):  "/dev/input/event3"
$ xinput enable 12

I have tried disabling all other keyboard devices, including having all of them disabled at once. I have tried float and reattach as described in another answer.

score 1 · Accepted Answer · answered Oct 18 '18 at 13:10

For some reason it is necessary to disable the pointer part of the keyboard device too:

$ xinput list
⎡ Virtual core pointer                      id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Razer Razer DeathAdder Chroma             id=9    [slave  pointer  (2)]
⎜   ↳ Razer Razer DeathAdder Chroma             id=10   [slave  pointer  (2)]
⎜   ↳ Corsair Corsair K70 RGB Gaming Keyboard   id=13   [slave  pointer  (2)]
⎣ Virtual core keyboard                     id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Power Button                              id=8    [slave  keyboard (3)]
    ↳ Razer Razer DeathAdder Chroma             id=11   [slave  keyboard (3)]
    ↳ Microsoft® LifeCam Studio(TM)             id=14   [slave  keyboard (3)]
    ↳ Dell WMI hotkeys                          id=15   [slave  keyboard (3)]
    ↳ Corsair Corsair K70 RGB Gaming Keyboard   id=12   [slave  keyboard (3)]

Disabling both 12 and 13 is effective.

Why do disabled input devices still work?

1 Answers1