Bug 99355

Summary: Use pressure, not just BTN_TOUCH for touch point detection on touchpads
Product: Wayland Reporter: Peter Hutterer <peter.hutterer>
Component: libinputAssignee: Wayland bug list <wayland-bugs>
Status: RESOLVED FIXED QA Contact:
Severity: normal    
Priority: medium CC: germano.massullo, peter.hutterer
Version: unspecified   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:
Bug Depends on:    
Bug Blocks: 94236, 94911, 96409, 99306, 99454    

Description Peter Hutterer 2017-01-11 02:11:55 UTC 
$subject says it all, this is mostly just a tracker bug so that we can have dependent bugs.

For comparison: 
synaptics behaviour is to use a Schmitt trigger with a default of 9.8% for 'low' and 11.7% for 'high' (25/256 and 30/256, respectively). There are model-specific cases, (some) apple touchpads use an absolute value range of 70/75 and all elantech touchpads just use the pressure minimum + 1.
The elantech value is questionable though and should be reviewed.


libinput likely needs some extra bits to be able to assign per-device values from the udev hwdb or similar.
Comment 1 Germano Massullo 2017-01-26 09:13:56 UTC 
Hi I have been brought here by https://bugs.kde.org/show_bug.cgi?id=375406#c2
You may be interested in it, even if it is xorg related.
Have a nice day
Comment 3 Peter Hutterer 2017-02-08 00:18:33 UTC 
commit 00d6b908d3b72859417c59b230b379f2ff47b1d8
Merge: b9b0f36 9e8f6bd
Author: Peter Hutterer <peter.hutterer@who-t.net>
Date:   Fri Feb 3 11:41:04 2017 +1000

    Merge branch 'touchpad-pressure-based-v2'

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