Apple Magic Trackpad: Three Finger Tap gets sent repeatedly

[Tom Beckmann]

When using my Magic Trackpad with up to two fingers all works fine, like scrolling and right clicking. As soon as I barely touch the pad with three fingers, it becomes unresponsive for around 20 seconds. Checking evtest, the same event is sent all the time, blocking all others.

evtest output after touching with three fingers:

Event: time 1393156544.500256, -------------- SYN_REPORT ------------
Event: time 1393156546.784405, type 3 (EV_ABS), code 47 (ABS_MT_SLOT), value 8
Event: time 1393156546.784405, type 3 (EV_ABS), code 57 (ABS_MT_TRACKING_ID), value 16
Event: time 1393156546.784405, type 3 (EV_ABS), code 48 (ABS_MT_TOUCH_MAJOR), value 108
Event: time 1393156546.784405, type 3 (EV_ABS), code 49 (ABS_MT_TOUCH_MINOR), value 120
Event: time 1393156546.784405, type 3 (EV_ABS), code 53 (ABS_MT_POSITION_X), value 2004
Event: time 1393156546.784405, type 3 (EV_ABS), code 54 (ABS_MT_POSITION_Y), value -460
Event: time 1393156546.784405, type 3 (EV_ABS), code 47 (ABS_MT_SLOT), value 9
Event: time 1393156546.784405, type 3 (EV_ABS), code 57 (ABS_MT_TRACKING_ID), value 17
Event: time 1393156546.784405, type 3 (EV_ABS), code 48 (ABS_MT_TOUCH_MAJOR), value 56
Event: time 1393156546.784405, type 3 (EV_ABS), code 49 (ABS_MT_TOUCH_MINOR), value 84
Event: time 1393156546.784405, type 3 (EV_ABS), code 53 (ABS_MT_POSITION_X), value -430
Event: time 1393156546.784405, type 3 (EV_ABS), code 54 (ABS_MT_POSITION_Y), value -785
Event: time 1393156546.784405, type 3 (EV_ABS), code 47 (ABS_MT_SLOT), value 10
Event: time 1393156546.784405, type 3 (EV_ABS), code 57 (ABS_MT_TRACKING_ID), value 18
Event: time 1393156546.784405, type 3 (EV_ABS), code 48 (ABS_MT_TOUCH_MAJOR), value 184
Event: time 1393156546.784405, type 3 (EV_ABS), code 49 (ABS_MT_TOUCH_MINOR), value 124
Event: time 1393156546.784405, type 3 (EV_ABS), code 53 (ABS_MT_POSITION_X), value 1040
Event: time 1393156546.784405, type 3 (EV_ABS), code 54 (ABS_MT_POSITION_Y), value -1008
Event: time 1393156546.784405, type 1 (EV_KEY), code 330 (BTN_TOUCH), value 1
Event: time 1393156546.784405, type 1 (EV_KEY), code 334 (BTN_TOOL_TRIPLETAP), value 1
Event: time 1393156546.784405, type 3 (EV_ABS), code 0 (ABS_X), value 2004
Event: time 1393156546.784405, type 3 (EV_ABS), code 1 (ABS_Y), value -460
Event: time 1393156546.784405, -------------- SYN_REPORT ------------
Event: time 1393156547.032985, type 1 (EV_KEY), code 334 (BTN_TOOL_TRIPLETAP), value 2
Event: time 1393156547.032985, -------------- SYN_REPORT ------------
Event: time 1393156547.068988, type 1 (EV_KEY), code 334 (BTN_TOOL_TRIPLETAP), value 2
Event: time 1393156547.068988, -------------- SYN_REPORT ------------
Event: time 1393156547.104987, type 1 (EV_KEY), code 334 (BTN_TOOL_TRIPLETAP), value 2
[...]

The last two rows are repeated until it eventually becomes responsive again.

This is on a ubuntu 14.04 system.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-11-generic 3.13.0-11.31
ProcVersionSignature: Ubuntu 3.13.0-11.31-generic 3.13.3
Uname: Linux 3.13.0-11-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.13.2-0ubuntu5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: tom 2066 F.... pulseaudio
CurrentDesktop: Pantheon
Date: Sun Feb 23 12:47:55 2014
HibernationDevice: RESUME=UUID=337ab8c5-44ab-4470-96a1-64d897d908c7
InstallationDate: Installed on 2013-11-16 (98 days ago)
InstallationMedia: elementary OS 0.3 "Isis" - Daily amd64 (20131109)
MachineType: ASUSTeK Computer Inc. N73SV
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-11-generic root=UUID=525ecdf6-9dc4-43f1-94cf-ac35f676f796 ro quiet splash crashkernel=384M-:128M
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-11-generic N/A
 linux-backports-modules-3.13.0-11-generic N/A
 linux-firmware 1.125
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/28/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: N73SV.303
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: N73SV
dmi.board.vendor: ASUSTeK Computer Inc.
dmi.board.version: 1.0
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer Inc.
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrN73SV.303:bd04/28/2011:svnASUSTeKComputerInc.:pnN73SV:pvr1.0:rvnASUSTeKComputerInc.:rnN73SV:rvr1.0:cvnASUSTeKComputerInc.:ct10:cvr1.0:
dmi.product.name: N73SV
dmi.product.version: 1.0
dmi.sys.vendor: ASUSTeK Computer Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Tom Beckmann (tombeckmann)]

What might also be helpful, hcidump shows that apparently the device stops sending new data with bluetooth as soon as I tap with three fingers. I only get a single output when tapping, after that it stops until evtest stops printing, too.

This is the last output I get:

> ACL data: handle 21 flags 0x02 dlen 36
    L2CAP(d): cid 0x0041 len 32 [psm 0]
      A1 28 C4 5A F3 96 03 4E FC 18 27 06 81 32 90 27 FD A7 01 0F
      43 F1 10 9C 7E 18 FC 0B 16 C4 A6 10

"Normal" output would look about like this, that's for a single finger:

> ACL data: handle 21 flags 0x02 dlen 18
    L2CAP(d): cid 0x0041 len 14 [psm 0]
      A1 28 A8 2D 00 5A 7D F0 0F 00 00 C0 81 74

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.13 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'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-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/v3.14-rc4-trusty/

[Tom Beckmann (tombeckmann)]

Tested with 3.14-rc4, exact same problem.

[Joseph Salisbury (jsalisbury)]

This issue appears to be an upstream bug, since you tested the latest upstream kernel. Would it be possible for you to open an upstream bug report[0]? That will allow the upstream Developers to examine the issue, and may provide a quicker resolution to the bug.

Please follow the instructions on the wiki page[0]. The first step is to email the appropriate mailing list. If no response is received, then a bug may be opened on bugzilla.kernel.org.

Once this bug is reported upstream, please add the tag: 'kernel-bug-reported-upstream'.

[0] https://wiki.ubuntu.com/Bugs/Upstream/kernel

[Tom Beckmann (tombeckmann)]

Could you maybe give me a hint who the maintainer would be in this case? I can't find anyone in that list who would really fit well.

[Tom Beckmann (tombeckmann)]

Appears to be fixed now by upstream.

[Stephen Pegoraro (spegoraro)]

Could you please advise of the upstream version which resolved the issue? This issue is present in other distros so it would be great to identify the cause.

[Sean Leonard (meanderingcode)]

I do not believe this is fixed in upstream kernel. I am using the linux-image-4.0.0-trunk-amd64 kernel package from experimental on my Debian jessie box and I am getting the bug behavior described here.