[PATCH v2] touchpad: add wobbling detection

[Konstantin Kharlamov]

On 21.02.2018 03:33, Peter Hutterer wrote:
>> It should work like it previously did; what bothers me however — shouldn't
>> that be specific to a touch, but not touchpad? Couldn't that get triggered
>> e.g. by 2-finger scrolling? (whatever that is, I dunno, touching with 2
>> finger doesn't scroll for me — I do scroll instead using the right edge of
>> the touchpad).
> 
> if you make it per-touch then yes, it can get triggered by 2-finger
> scrolling but it'll work per-touch so either touch has to wobble to disable
> the hysteresis. we can assume that if one touch wobbles, all of them will.
> 
> 2-finger scrolling can be enabled with the
> libinput_device_config_set_scroll_method() call, or libinput debug-events
> --set-scroll-method=twofinger, you should give it a try. edge scrolling is
> going the way of the dodo.

Thanks for your comments! Enabling 2-finger scroll did end up in crash 
for me previously, but it's fixed in git already. I did enable it with

	$ xinput set-prop "SynPS/2 Synaptics TouchPad" "libinput Scroll Method 
Enabled" 1 0 0

Well, can't say I'm a fan. It's possible I haven't got used to it yet, 
but for me it's not very comfortable because when I'm trying to scroll 
with 2 fingers, the cursor also starts moving at the beginning, so if 
e.g. I'm trying to scroll something small, or if my cursor is simply at 
the top of a scrollable widget — it can quit out of scrollable zone. And 
even when it starts working, it's sometimes stops scrolling and cursor 
starts moving…

I dunno, it might have something to do with my touchpad being "wobbly"… 
Either way, side scrolling definitely have no such point of failure, 
it's always reliable.