[bionic] Dell precision touchpad RMB no longer works

[Oded Arbel]

Using the clickable touchpad on the Dell Precision 5520, the "right mouse button" (an area marked on the bottom right of the touchpad) no longer produces an RMB event when clicked. This used to work in Artful.

More details:
The Dell Precision touchpad is "clickable" - i.e. when pressed firmly it produces a click sound and triggers an LMB event even without raising the finger from the touchpad. This allows you to move the cursor around quickly and clicking on things without having to stop and raise your finger from the surface.

Additionally, the touchpad has a marked bottom area that is split into two horizontally. When clicking (not tapping) on the right part of the bottom area, it should simulate a right mouse button click, while on the left part it should simulate a left mouse button click. This used to work well under Artful, but does no longer work in Bionic - both sides produce a left click (with some caveats, the left side doesn't seem to work so well, but that is probably another issue).

When running libinput-debug-events, the output clearly shows that the touchpad "right mouse button" clearly sends RMB events:

 event11 POINTER_MOTION +33.83s 0.00/ 1.19
 event11 POINTER_MOTION +33.85s 0.00/ 0.99
 event11 POINTER_BUTTON +38.62s BTN_RIGHT (273) pressed, seat count: 1
 event11 POINTER_BUTTON +38.80s BTN_RIGHT (273) released, seat count: 0
 event11 POINTER_BUTTON +39.35s BTN_RIGHT (273) pressed, seat count: 1
 event11 POINTER_BUTTON +39.56s BTN_RIGHT (273) released, seat count: 0
 event11 POINTER_BUTTON +40.02s BTN_RIGHT (273) pressed, seat count: 1
 event11 POINTER_BUTTON +40.19s BTN_RIGHT (273) released, seat count: 0
 event11 POINTER_MOTION +42.66s -0.73/ 0.73
 event11 POINTER_MOTION +42.67s -0.60/ 0.60

None the less, X11 doesn't seem to recognize this - xev output shows:

ButtonPress event, serial 40, synthetic NO, window 0x6200001,
    root 0x16a, subw 0x222c01, time 369378629, (92,88), root:(92,117),
    state 0x10, button 1, same_screen YES

EnterNotify event, serial 40, synthetic NO, window 0x6200001,
    root 0x16a, subw 0x0, time 369378629, (92,88), root:(92,117),
    mode NotifyGrab, detail NotifyInferior, same_screen YES,
    focus YES, state 272

KeymapNotify event, serial 40, synthetic NO, window 0x0,
    keys: 106 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
           0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

UnmapNotify event, serial 40, synthetic NO, window 0x6200001,
    event 0x6200001, window 0x222c01, from_configure NO

EnterNotify event, serial 40, synthetic NO, window 0x6200001,
    root 0x16a, subw 0x0, time 369378630, (92,88), root:(92,117),
    mode NotifyNormal, detail NotifyInferior, same_screen YES,
    focus YES, state 272

KeymapNotify event, serial 40, synthetic NO, window 0x0,
    keys: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
           0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

DestroyNotify event, serial 40, synthetic NO, window 0x6200001,
    event 0x6200001, window 0x222c01

ButtonRelease event, serial 40, synthetic NO, window 0x6200001,
    root 0x16a, subw 0x0, time 369378797, (92,88), root:(92,117),
    state 0x110, button 1, same_screen YES

While with a two finger tap, when enabling tap mouse button emulation, xev shows "button 3" being pressed.

[Oded Arbel (oded-geek)]

Reading into it a bit, it could be an issue with libinput, which Bionic ships version 1.10 (over Artful's 1.8).

[Oded Arbel (oded-geek)]

Confirmed this is a libinput regression - I've built and installed libinput 1.8.4 from Artful and that returned the RMB click functionality (though of course many other things that rely on libinput >= 1.9 broke).

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1759300, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.

[Oded Arbel (oded-geek)]

After several upgrades/downgrades of libinput and reboots, including setting up xinput quirks according to http://www.dell.com/support/article/ca/en/cabsdt1/sln308258/precision-xps-ubuntu-general-touchpad-mouse-issue-fix?lang=en, the problem seems to have gone away and the touchpad correctly reports RMB clicks.