Ttgjyuk

Problem Definition

When using the touchpad, the cursor sometimes jumps around a small amount and often fails to detect touch-click.

Attempted Solutions

Some searching suggested installing the old synaptics stuff, which had a dependency on xserver-xorg-core, which was not installed. Installing the package and all its concommitant dependencies yielded a GUI that not only didn't honor the touchpad, but didn't permit keyboard input. Reinstalled Linux from scratch.

Some History

https://bugs.freedesktop.org/show_bug.cgi?id=104828

It looks like Wayland is now the main vehicle, and some very good work has been done here. One of the commenters expresses concern about CPU usage, a concern I would take issue with given the critical nature of human-mouse pointer coupling (i.e. we're doing this for one process, not 1,000 processes; a little extra CPU for something critical isn't a big deal).

xinput list

xinput list
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ AlpsPS/2 ALPS DualPoint TouchPad id=13 [slave pointer (2)]
⎜ ↳ AlpsPS/2 ALPS DualPoint Stick id=14 [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)]
 ↳ Video Bus id=8 [slave keyboard (3)]
 ↳ Power Button id=9 [slave keyboard (3)]
 ↳ Sleep Button id=10 [slave keyboard (3)]
 ↳ Dell WMI hotkeys id=11 [slave keyboard (3)]
 ↳ AT Translated Set 2 keyboard id=12 [slave keyboard (3)]
 ↳ 40:EF:4C:BE:00:4C id=15 [slave keyboard (3)]

xinput list-props "AlpsPS/2 ALPS DualPoint TouchPad"

xinput list-props "AlpsPS/2 ALPS DualPoint TouchPad"
Device 'AlpsPS/2 ALPS DualPoint TouchPad':
 Device Enabled (149): 1
 Coordinate Transformation Matrix (151): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
 libinput Tapping Enabled (284): 1
 libinput Tapping Enabled Default (285): 0
 libinput Tapping Drag Enabled (286): 0
 libinput Tapping Drag Enabled Default (287): 1
 libinput Tapping Drag Lock Enabled (288): 0
 libinput Tapping Drag Lock Enabled Default (289): 0
 libinput Tapping Button Mapping Enabled (290): 1, 0
 libinput Tapping Button Mapping Default (291): 1, 0
 libinput Natural Scrolling Enabled (292): 0
 libinput Natural Scrolling Enabled Default (293): 0
 libinput Disable While Typing Enabled (294): 1
 libinput Disable While Typing Enabled Default (295): 1
 libinput Scroll Methods Available (296): 1, 1, 0
 libinput Scroll Method Enabled (297): 1, 0, 0
 libinput Scroll Method Enabled Default (298): 1, 0, 0
 libinput Middle Emulation Enabled (299): 1
 libinput Middle Emulation Enabled Default (300): 1
 libinput Accel Speed (301): 0.000000
 libinput Accel Speed Default (302): 0.000000
 libinput Left Handed Enabled (303): 0
 libinput Left Handed Enabled Default (304): 0
 libinput Send Events Modes Available (269): 1, 1
 libinput Send Events Mode Enabled (270): 0, 0
 libinput Send Events Mode Enabled Default (271): 0, 0
 Device Node (272): "/dev/input/event6"
 Device Product ID (273): 2, 8
 libinput Drag Lock Buttons (305): <no items>
 libinput Horizontal Scroll Enabled (306): 1

Note there is no "FingerHigh", "FingerLow" or the other usual properties people suggest changing.

Workaround

Notice the matrix in the properties above. The AlpsPS/2 DualPoint Stick also has such a matrix; by setting the x and y values to something really small, I'm able to achieve precise control using the stick, ergo:

 Coordinate Transformation Matrix (151): 0.050000, 0.000000, 0.000000, 0.000000, 0.050000, 0.000000, 0.000000, 0.000000, 1.000000

This gives me fine-tuned control for 3D model building and CAD work.

My Question to the Community

If anyone has been successful achieving smoother TouchPad operation with this hardware, I would be most interested to know how. My system is a solid older Dell which otherwise mates up very nicely with Ubuntu 18.04.

Thank you.