alternate finger tapping causes cursor to jump
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
xserver-xorg-input-synaptics (Ubuntu) |
Invalid
|
Undecided
|
Unassigned |
Bug Description
I've found that if I quickly alternate tapping with two fingers on the touchpad the cursor jumps wildly.
This is quite frustrating for me as I often move the cursor with one finger on my right hand while subsequently clicking the bottom left of the touchpad with the left to cause a 'left click' action. Often this causes my mouse to jump to the bottom left of the screen and open the cinnamon menu window.
It seems if I monitor events with xinput that the a[0] and a[1] events are being swapped.
motion a[0]=4734
motion a[0]=4734
motion a[0]=4733
motion a[1]=1984
motion a[1]=1983
motion a[1]=1982
motion a[1]=1980
motion a[1]=1983
motion a[1]=1987
motion a[1]=1991
motion a[1]=1996
motion a[1]=2001
motion a[0]=2760 a[1]=4719 <-- Jump happens here
...
Example 2:
motion a[0]=4578
motion a[0]=4578
motion a[0]=4577
motion a[0]=4577
motion a[0]=4576
motion a[0]=4575
motion a[0]=4575
motion a[1]=1990
motion a[1]=1989
motion a[1]=1987
motion a[1]=1986
motion a[1]=1984
motion a[1]=1983
motion a[0]=4577 a[1]=1977
motion a[0]=1472 a[1]=4719 <-- Jump happens here
motion a[0]=1472 a[1]=4722
I would have thought that the synaptics driver code would have identified 'erratic' input events which appear to be too far apart to be naturally occurring and simply filter them out?
I could not repeat this when I loaded an Ubuntu 13.10 Live USB disk but the Synaptics TouchPad driver did not appear to be loaded at that time as it didn't appear in xinput list.
~> lsb_release -rd
Description: Linux Mint 16 Petra
Release: 16
~>uname -a
Linux chris-XPS13 3.11.0-12-generic #19-Ubuntu SMP Wed Oct 9 16:20:46 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
~> dpkg -l | grep input-synaptics
ii xserver-
ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: xserver-
ProcVersionSign
Uname: Linux 3.11.0-12-generic x86_64
ApportVersion: 2.12.5-0ubuntu2.2
Architecture: amd64
Date: Mon Feb 24 21:00:55 2014
InstallationDate: Installed on 2014-02-13 (11 days ago)
InstallationMedia: Linux Mint 16 "petra" - Release amd64 20131126
MarkForUpload: True
ProcEnviron:
TERM=screen
PATH=(custom, no user)
XDG_RUNTIME_
LANG=en_GB.UTF-8
SHELL=
SourcePackage: xserver-
UpgradeStatus: No upgrade log present (probably fresh install)
Status changed to 'Confirmed' because the bug affects multiple users.