Microsoft Ergonomic Keyboard 4000 has two input devices

[Michał Zając]

Recently I have noticed that Zoom In/Out slider on my Microsoft Ergonomic Keyboard 4000 stopped working. I tried investigating what's wrong and noticed that my keyboard reports as two different input devices according to evtest

sudo evtest output:
(...)
/dev/input/event2: Microsoft Natural® Ergonomic Keyboard 4000
/dev/input/event3: Microsoft Natural® Ergonomic Keyboard 4000
(...)

/dev/input/event2 responds to normal keys
/dev/input/event3 responds to multimedia keys and zoom in/out keys

The most puzzling thing is that multimedia keys actually work and be bound. For example I have bound KEY_F17 to Next track in Amarok. Play/pause, Vol. Up/Down and Mute worked out of box.

uname -a:
Linux demonbane 3.16.0-55-generic #74~14.04.1-Ubuntu SMP Tue Nov 17 10:15:59 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

lsb_release -rd:
Description: Ubuntu 14.04.3 LTS
Release: 14.04

[Michał Zając (quintasan)]

xev fires no events for the zoom in/out slider but does fire events for multimedia keys

sudo evtest with event3 device yields the following for zoom in/out slider:
Event: time 1449522782.778509, type 4 (EV_MSC), code 4 (MSC_SCAN), value c022d
Event: time 1449522782.778509, type 1 (EV_KEY), code 418 (KEY_ZOOMIN), value 1
Event: time 1449522782.778509, -------------- SYN_REPORT ------------
Event: time 1449522782.906509, type 4 (EV_MSC), code 4 (MSC_SCAN), value c022d
Event: time 1449522782.906509, type 1 (EV_KEY), code 418 (KEY_ZOOMIN), value 0
Event: time 1449522782.906509, -------------- SYN_REPORT ------------
Event: time 1449522783.290512, type 4 (EV_MSC), code 4 (MSC_SCAN), value c022e
Event: time 1449522783.290512, type 1 (EV_KEY), code 419 (KEY_ZOOMOUT), value 1
Event: time 1449522783.290512, -------------- SYN_REPORT ------------
Event: time 1449522783.354512, type 4 (EV_MSC), code 4 (MSC_SCAN), value c022e
Event: time 1449522783.354512, type 1 (EV_KEY), code 419 (KEY_ZOOMOUT), value 0
Event: time 1449522783.354512, -------------- SYN_REPORT ------------

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.