[RFC] libinput configuration interface

Peter Hutterer peter.hutterer at who-t.net
Thu Mar 27 16:10:53 PDT 2014


On Thu, Mar 27, 2014 at 07:34:37PM +0600, Alexander E. Patrakov wrote:
> 2014-03-27 19:22 GMT+06:00 Alexander E. Patrakov <patrakov at gmail.com>:
> 
> (regarding slow scrolling)
> 
> > I don't think so. I have tried to reproduce the bug by hand. It still
> > exists, but ./tools/event-debug still picks the scrolling up
> > correctly. I guess that this tool output already has the finger motion
> > averaging logic applied, so this speaks against your hypothesis. An
> > interesting observation that can ring some bells: Chromium picks up
> > the scroll events if and only if event-debug prints values whose
> > absolute value is greater than 10. Maybe the driver fails to combine
> > several small scroll events into a big one, or rounds the individual
> > scroll amounts instead of the accumulated value?
> 
> I have also tested regular (X/Y) pointer motion, and noticed the same
> pattern. event-debug properly reports sub-pixel motion (i.e. prints
> values below 1.0 if I move the finger slowly), but such multiple
> sub-pixel motions are never added up into proper pointer events that
> actually move the X pointer by at least one pixel.

yeah, I found that yesterday and it's a xf86-input-libinput issue.
Conversion to integers would just drop small values. I've pushed a fix to
use valuator masks with doubles now and that seems to fix the issue.
Try 1ab6637b56272bb5cef0568a785e2e5948e6b022.

Cheers,
   Peter


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