--- Comment #22 from Peter Hutterer <peter.hutte...@who-t.net> ---
Some notes after another afternoon of playing around with this:
The script that produces the output above measures *physical* movements on the
touchpad, thus the 'speed' on the right column represent 10mm/s physical
movement, not pointer movement. IMO it makes sense that the majority comes in
at below 20mm/s. Slow movements generate more events, fast movements are
*short* movements with few events.
I played around with a bunch of acceleration curves similar to attachment
136584. I used a linear curve instead for simplicity with varying inclines,
starting acceleration at 40mm/s, inclines from 'roughly parallel to current' to
'roughly like attachment 136584'. They showed the same thing every time: the
pointer is uncontrollable once we hit accel factor 3  at anything but very
low speeds. The fast pointer movement is multiplied by a high factor, resulting
in ridiculous deltas and unpredictable pointers.
A fixed factor 3 is just about controllable but would cause RSI after 5 min.
I have in front of me: Lenovo T440s, Lenovo T450s, Dell XPS 13 9365, Asus
E402S. All with Fedora 27, up-to-date (libinput 1.10.1). The touchpad behaviour
is effectively identical  on all four machines.
Bug 105375 is the next step here, once that's implemented we can at least
compare full output. But right now, I know just as much as before :(
All that aside, please confirm that you do *not* have a hidpi screen though.
 factor 3 not accounting for the TP_MAGIC_SLOWDOWN, so effective factor 3 *
 The XPS has a hidpi screen and is slow under X, GNOME on wayland makes up
for this but that's not a libinput issue.
You are receiving this mail because:
You are the assignee for the bug.
wayland-bugs mailing list