touchpad: add quirk for the T450 and T460 generation hardware
The touchpad's sensors are too far apart (or the firmware interferes), causing
in a jerky movement visible especially on slow motion. We get a bunch of
normal motion events, then only ABS_MT_PRESSURE updates without x/y updates.
After about one mm of movement x/y updates resume, with the first event
covering the distance between the last motion event. That event is usually
accelerated and thus causes a large jump. Subsequent events are sufficiently
fine-grained again.
This patch counts the number of non-motion events. Once we hit 10 in a row, we
mark the first motion update as non-dirty, effectively discarding the motion
and thus stopping the pointer jumps.
https://bugs.freedesktop.org/show_bug.cgi?id=94379
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Tested-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>