Ubuntu – Mouse scroll needs 17 ticks to register 1 movement on fresh Ubuntu 19.04

Won't Fix, at least, this is current status with libinput

• Upstream bug report: freedesktop - libinput - Support setting scroll speed #185

  1. Mice manufacturer uses different high-resolution scroll implementations
  2. Scroll speed need to be variable and controlled by applications depending on context

• Old solution were working with evdev

• Setting method: xinput, xorg.conf.d

Workaround, using Udev HWDB (Low level fix)

• (1) HWDB setting within udev for specific mouse model.

  Source: U&L: Change scroll speed with libinput

  I confirm, it is current solution from Upstream code repository of udev

  1. Check your mouse identification: Vendor ID, Product ID, Device Name

     While mouse plugged in

     sudo lsusb
     

     Run one of commands below then reconnect the mouse

     sudo udevadm monitor -u
     sudo journalctl -k -b -f
     

     And check systemd/hwdb.d/70-mouse.hwdb or look for local file /lib/udev/hwdb.d/70-mouse.hwdb in your system. Search for same or similar device.

  2. Open terminal, create the 71-mouse-local.hwdb file

     sudo nano /etc/udev/hwdb.d/71-mouse-local.hwdb
     

  3. Copy from step (1) these lines and append them to the new file, Add wheel click angle entry and set angle as you want (default=15 degree/click, as integer value), as bellow:

     # Microsoft Comfort Mouse 4500
     mouse:usb:v045ep076c:name:Microsoft Microsoft® Comfort Mouse 4500:
      MOUSE_DPI=1000@125
      MOUSE_WHEEL_CLICK_ANGLE=15
     

     If you can't find your device in 70-mouse.hwdb, create it in this format with information collected in step (1)

     mouse:usb:v <VendorID> p <ProductID> :name: <DeviceName> :
     

  4. Save and close

     Ctrl+O , Ctrl+X

  5. Update udev hardware database, trigger the change for corresponding event node

     sudo systemd-hwdb update
     sudo udevadm trigger /dev/input/event16
     

     event16 as reported in xinput output.

  Note

  This answer is customized for the OP case but can be tuned for another model. Already expended it to be more generic.

  • Full upstream instructions are here: systemd/hwdb.d/70-mouse.hwdb or look for local file 70-mouse.hwdb in your system. Also you may look other advanced feature in there.

  • There is MOUSE_WHEEL_CLICK_COUNT which overrides MOUSE_WHEEL_CLICK_ANGLE, use it when angle parameter is not precise enough.

    MOUSE_WHEEL_CLICK_COUNT default=24 click/rotation or click/360deg, accepts integer value

    Example:

    # Microsoft Comfort Mouse 4500
    mouse:usb:v045ep076c:name:Microsoft Microsoft® Comfort Mouse 4500:
     MOUSE_DPI=1000@125
     MOUSE_WHEEL_CLICK_ANGLE=15
     MOUSE_WHEEL_CLICK_COUNT=24
    

    MOUSE_WHEEL_CLICK_ANGLE is a must for compatibility reasons even its value is not effective with declared MOUSE_WHEEL_CLICK_COUNT.

Future, GUI tool kits (High level fix)

• (2) Probably get implemented at the level of GUI tool kits. Fair hopes when it comes to collaboration between large free community projects, like it is the case for arbitrary Unicode input, it got implemented only in GTK.

  Some apps won't wait for that, like some browsers and games (Firefox, Chromium, SDL games, ..).

  There is a list of bug report from GUI kits in the linked bug report above.

I'm also having this problem. So far, this doesn't throw an error:

$ xinput --set-prop 17 --type=float --format=32 "Evdev Scrolling Distance" 1

But it doesn't actually change anything, at least for me. I'll keep trying...

Edit: I found the manpage for evdev here. I didn't glean enough from it to solve it. I'm sure it would be interesting to figure out another time, though.

In continuing to read, I found a little program called imwheel that works.

sudo apt install imwheel

Then create an rc file:

vim ~/.imwheelrc

".*"
None,      Up,   Button4, 7
None,      Down, Button5, 7
Control_L, Up,   Control_L|Button4
Control_L, Down, Control_L|Button5
Shift_L,   Up,   Shift_L|Button4
Shift_L,   Down, Shift_L|Button5

Where lines 2 and 3 end with '7', which is the scroll distance (default '3'). Try playing with it, just do imwheel --kill then imwheel to reload changes. The last four lines introduce standard behavior between shift/control and scrolling.

The full guide is here and has more info.