[Lenovo ThinkPad T460s] Mouse pointer jumps to the bottom on the screen on some pad touchs

[Facundo Batista]

When using normally the touchpad, sometimes it jumps to (mostly) the bottom of the screen. It jumps to any position in the bottom, not the corners.

Also, sometimes it jumps to the top. This is not random jumping, or erratic movement. It jumps to the bottom on some touchs.

I found that it's quite reproducible if you play a little with two fingers on the pad, not moving the pointer but just touching the pad with one finger, then with the other, then with the first, etc, in rapid succession.

I'm happy to help with any debugging.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-34-generic 4.4.0-34.53
ProcVersionSignature: Ubuntu 4.4.0-34.53-generic 4.4.15
Uname: Linux 4.4.0-34-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: facundo 3451 F.... pulseaudio
CurrentDesktop: Unity
Date: Wed Aug 17 17:55:42 2016
HibernationDevice: RESUME=UUID=340cc03c-dbf5-43e8-9df1-54c80503a2bf
InstallationDate: Installed on 2016-07-29 (18 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 003: ID 5986:0706 Acer, Inc
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: LENOVO 20F9CTO1WW
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-34-generic.efi.signed root=UUID=c1ae597a-f554-417b-872a-ac0cf8710fe7 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-34-generic N/A
 linux-backports-modules-4.4.0-34-generic N/A
 linux-firmware 1.157.3
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/14/2016
dmi.bios.vendor: LENOVO
dmi.bios.version: N1CET43W (1.11 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20F9CTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40700 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrN1CET43W(1.11):bd04/14/2016:svnLENOVO:pn20F9CTO1WW:pvrThinkPadT460s:rvnLENOVO:rn20F9CTO1WW:rvrSDK0J40700WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.name: 20F9CTO1WW
dmi.product.version: ThinkPad T460s
dmi.sys.vendor: LENOVO

[Brad Figg (brad-figg)]

This change was made by a bot.

[Facundo Batista (facundo)]

I started xpinut to show the events, the attached is a series of events when this jump happens (around the last 5 or 10 events, it's very difficult to pinpoint the exact place).

The command I used is:

    xinput --test "SynPS/2 Synaptics TouchPad"

[Joseph Salisbury (jsalisbury)]

Did this issue start happening after an update/upgrade? Was there a prior kernel version where you were not having this particular problem?

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.8 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.8-rc2/

[Facundo Batista (facundo)]

It looks it's fixed in mainline kernel, now it's not happening. Note that I tried v4.8 rc3

[Facundo Batista (facundo)]

I'm sorry to inform that after more heavy using, this is still happening in the new kernel, but less frequently :/

It still happens, now it just isn't so amusing all the time...

[penalvch (penalvch)]

Facundo Batista, to keep this relevant to upstream, one would want to test the latest mainline kernel (now 4.8-rc5) as it is released.

Could you please advise?

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]

[Facundo Batista (facundo)]

I tested this with kernel mainline 4.9rc4 and the problem is still there.

[Facundo Batista (facundo)]

I tried with 4.10 rc1, still happening.

[Facundo Batista (facundo)]

Adding a example video where I show the bug. See the mouse pointer in the eye's pupil. See what I do then with my fingers in the touchpad, and how the mouse pointer jumps to a screen's corner.

[Facundo Batista (facundo)]

Hi! Problem is still happening after the BIOS update :(

$ sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date
[sudo] password for facundo:
N1CET52W (1.20 )
11/30/2016

[Facundo Batista (facundo)]

BTW, reproducing the bug with updated BIOS *and* latest kernel:

$ uname -r
4.10.0-041000rc1-generic

[penalvch (penalvch)]

Facundo Batista, to clarify, did this issue start occurring after a software update, or upgrading from a prior Ubuntu release?

[Facundo Batista (facundo)]

It happened from "always", I bought the machine brand new at the end of July, and after some days of use I just reported the bug.