Before I go randomly installing any additional software, I'd like to understand how xinput works and why there's nothing related to scrolling speed for my mouse.
Could you please enlighten me?
Ubuntu 18.04.1 LTS x64, GNOME 3.28.2 (not sure if it matters). Up to date.
$ xinput list
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ ETPS/2 Elantech Touchpad id=11 [slave pointer (2)]
⎜ ↳ Microsoft Microsoft® Comfort Mouse 4500 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)]
↳ HP TrueVision HD Camera: HP Tru id=8 [slave keyboard (3)]
↳ Intel Virtual Button driver id=9 [slave keyboard (3)]
↳ AT Translated Set 2 keyboard id=10 [slave keyboard (3)]
↳ HP Wireless hotkeys id=12 [slave keyboard (3)]
↳ HP WMI hotkeys id=13 [slave keyboard (3)]
↳ Microsoft Microsoft® Comfort Mouse 4500 id=15 [slave keyboard (3)]
↳ Chicony USB Keyboard id=16 [slave keyboard (3)]
↳ Chicony USB Keyboard id=17 [slave keyboard (3)]
Details of the mouse under "pointers":
$ xinput list-props 14
Device 'Microsoft Microsoft® Comfort Mouse 4500':
Device Enabled (142): 1
Coordinate Transformation Matrix (144): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Natural Scrolling Enabled (289): 0
libinput Natural Scrolling Enabled Default (290): 0
libinput Scroll Methods Available (293): 0, 0, 1
libinput Scroll Method Enabled (294): 0, 0, 0
libinput Scroll Method Enabled Default (295): 0, 0, 0
libinput Button Scrolling Button (727): 2
libinput Button Scrolling Button Default (728): 2
libinput Middle Emulation Enabled (729): 0
libinput Middle Emulation Enabled Default (730): 0
libinput Accel Speed (296): -0.258993
libinput Accel Speed Default (297): 0.000000
libinput Accel Profiles Available (731): 1, 1
libinput Accel Profile Enabled (732): 1, 0
libinput Accel Profile Enabled Default (733): 1, 0
libinput Left Handed Enabled (298): 0
libinput Left Handed Enabled Default (299): 0
libinput Send Events Modes Available (266): 1, 0
libinput Send Events Mode Enabled (267): 0, 0
libinput Send Events Mode Enabled Default (268): 0, 0
Device Node (269): "/dev/input/event16"
Device Product ID (270): 1118, 1900
libinput Drag Lock Buttons (300): <no items>
libinput Horizontal Scroll Enabled (301): 1
Only parts related to scrolling:
$ xinput list-props 14 | grep -i 'scroll' libinput Natural Scrolling Enabled (289): 0 libinput Natural Scrolling Enabled Default (290): 0 libinput Scroll Methods Available (293): 0, 0, 1 libinput Scroll Method Enabled (294): 0, 0, 0 libinput Scroll Method Enabled Default (295): 0, 0, 0 libinput Button Scrolling Button (727): 2 libinput Button Scrolling Button Default (728): 2 libinput Horizontal Scroll Enabled (301): 1
Details of the mouse under "keyboard":
$ xinput list-props 15
Device 'Microsoft Microsoft® Comfort Mouse 4500':
Device Enabled (142): 1
Coordinate Transformation Matrix (144): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Send Events Modes Available (266): 1, 0
libinput Send Events Mode Enabled (267): 0, 0
libinput Send Events Mode Enabled Default (268): 0, 0
Device Node (269): "/dev/input/event16"
Device Product ID (270): 1118, 1900
libinput Accel Speed
is about?