#349 touchscreen stopped dragging with finger

[Ondrej Bojar]

Hi,

This may not be your bug at all, but I'm failing to find a better place to ask. I am very new to touchscreens and I never used tablets (I mean the input devices).

I have Lenovo Yoga 370 with Ubuntu 16.04.3 LTS (xenial), touch screen.

My xinput --list says:

⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ Wacom Co.,Ltd. Pen and multitouch sensor Pen stylus id=10 [slave pointer (2)]
⎜ ↳ Wacom Co.,Ltd. Pen and multitouch sensor Pen eraser id=16 [slave pointer (2)]
⎜ ↳ ETPS/2 Elantech TrackPoint id=14 [slave pointer (2)]
⎜ ↳ ETPS/2 Elantech Touchpad id=13 [slave pointer (2)]
⎜ ↳ Wacom Co.,Ltd. Pen and multitouch sensor Finger touch id=9 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
↳ Power Button id=6 [slave keyboard (3)]
↳ Video Bus id=7 [slave keyboard (3)]
↳ Sleep Button id=8 [slave keyboard (3)]
↳ Integrated Camera id=11 [slave keyboard (3)]
↳ AT Translated Set 2 keyboard id=12 [slave keyboard (3)]
↳ ThinkPad Extra Buttons id=15 [slave keyboard (3)]

Everything worked out of the box (amazing!): touchpad, nipple, touchscreen with my finger, touchscreen with the pen. (I have no idea how the 'eraser' side of the pen is supposed to work.)

Without any obvious reasons, I can no longer drag with my finger on the touch screen. Clicking works, dragging with the pen works too.
The only thing that comes to my mind is some miscalibration, because someone unintentionally touched my screen with half a palm.

Or could it possibly be a bad mapping to X events?

I have no idea how to recalibrate or diagnose this further.

Would you have any suggestions?

Any help much appreciated.

Thanks, Ondrej.

[Jason Gerecke]

It is possible for the driver to occasionally become confused about the current state of touches (and we're working on fixing those issues where we find them), but a reboot will typically reset everything back to working order. Do drags not work even after a reboot? Are you able to perform a few drags before things stop working again? Does the problem only start after using the pen? When did this first start happening?

[Ondrej Bojar]

I am happy to confirm that after the restart (a very cold start, actually), the problem disappeared.

Before the restart, my children also touched the screen in a strange way and even clicking was no longer recognized.

Is there a way to reset the driver without rebooting?

Thanks, Ondrej.

[Max Teegen]

I am experiencing a similar issue with my Thinkpad X1 Yoga (1st Gen).
After some time of using touchscreen and pen together, the touchscreen randomly stops reacting to dragging.

I recorded a log from xinput test-xi2, you can see toward the end that no more RawTouchUpdate events appear. I then ran evemu-record and it still seems to get position updates.

Logging out and back in fixes the problem.

[Mario Botsch]

I have exactly the same problem with a Thinkpad X1 Yoga (2nd gen). I happens rarely and the problem is hard to reproduce, but when giving a 1h presentation talk it will happen at some point.

Is there any way to reset the status of the driver without restarting X (and thereby killing my presentation)?

[Jason Gerecke]

Sorry for the delayed reply Ondrej, Max, and Mario. Although I don't believe its possible to reload the X driver without logging out (or rebooting), there's a chance that reloading the kernel driver will temporarily resolve the issue. Please try running sudo modprobe -r wacom && sudo modprobe wacom the next time the toushcreen stops responding. Please reply back if doing that works for you or not -- it may give us a clue about where the problem lies.

[Max Teegen]

Just had this occur again, and sudo modprobe -r wacom && sudo modprobe wacom fixed it.

[Chris Sutherland]

I can confirm the same issue with a Cintiq Companion 2. Don't know if this helps, but it seems like drumming your fingers on the screen like you would on a desk is an easy way to replicate this.

[Jason Gerecke]

I may have found the source of this bug. Please follow the steps below to compile and install a fixed version of the driver (you can find a list of necessary build dependencies at http://linuxwacom.sourceforge.net/wiki/index.php/Xf86-input-wacom). Let me know if you're still able to reproduce this issue afterwards.

$ git clone https://github.com/jigpu/xf86-input-wacom.git -b fix-touch-freeze
$ cd xf86-input-wacom
$ ./autogen.sh --prefix=/usr --libdir=$(for F in /usr/lib*/xorg/modules/input/../../../; do readlink -e $F; done | head -n1)
$ make
$ sudo make install

Afterwards, logout and login to restart X. Check the output of journalctl -b0 or the latest /var/log/Xorg.*.log or ~/.local/share/xorg/Xorg.*.log file for a "Build version line. It should indicate version "0.36.0.2.g85759e6" if the modified driver was correctly installed.

[Mario Botsch]

Dear Jason,

your fix indeed seems to solve the problem! Now touch-drag does not freeze anymore, even when drumming crazily with the fingers, which before reproduced the problem within seconds. Cool!

Your fix also solves my remaining problems with pen input, which after some time (in Chrome, using Javascript) stopped working. It still produced pen-down, but no more pen-move events. That problem might partially be a Chrome-related issue, since it didn't happen with Xournal, but now this problem is also gone with the new version.

Thanks a lot, that's really great!

[Jason Gerecke]

Closing as fixed by 414ee8130dd8b04512f38b7d9d29ecce3e30a86e in xf86-input-wacom 0.36.1