Pen on PC tablet works unreliably

Support
1

I have a Dell Latitude 7390 2-in-1, with a pen. I’m using Manjaro with the standard Gnome desktop environment.

The pen works out of the box, unfortunately for whatever reason it will stop being picked up by the wacom sensor and then it will start being detected again. When it works, the pen functions really well, but these interruptions make it unusable for any actual work.

I’m completely at a loss about how to even start troubleshooting the issue. For example, the command xev, doesn’t seem to announce anything when the stylus/pen is picked up. Also the touchpad and stylus configuration has nothing to help.

Finally I can report that I have a separate Wacom Intuos tablet, which runs over bluetooth, that works reliably.

2

Hello,

Is this your model?
https://wiki.archlinux.org/index.php/Dell_XPS_13_2-in-1_(7390)
Maybe you find some useful information there.

Do you have xf86-input-wacom package installed? Some Stylus models require that to work properly.

3

Hi, thanks for your reply. My machine is a Lattitude 7390, not an XPS 7390, but I don’t think it’s important.

xf86-wacom-input was installed, and as I said the pen works (there is even pressure sensitivity) the issue is just that it sporadically stops being detected. For example it will stop working while I am writing, like right in thr middle of a word, and then a few seconds later start working again.

I’m really looking for a way to diagnose the issue. Maybe a log of some sorts.

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Is there some log file, or other program that gives some kind of output once a pen/stylus is picked up and once it is no longer picked up?

5

Hmm… okay. Well I did some digging around and found: gttps://medium.com/tutorials-with-ganofins/how-to-enable-or-disable-the-touchscreen-in-manjaro-or-arch-linux-dce1f7fd349e. Which mentions the utility xinput (installed via the package xorg-xinput)

Running xinput list shows my pen has id=11 and running xinput query-status 11 (xinput query-status 11 | tail for a shorter version) gives:

ValuatorClass Mode=Absolute Proximity=Out
        valuator[0]=19386
        valuator[1]=3097
        valuator[2]=8
        valuator[3]=0
        valuator[4]=0
        valuator[5]=-900

when the pen is not detected and when the pen is detected I get

ValuatorClass Mode=Absolute Proximity=In
(...)

If I write for long enough the pen switches from Proximity=In to Proximity=Out even though I am in the middle of writing a word. Eventually the pen is picked up again.

Running xinput list shows:

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ DELL0823:00 044E:120A Touchpad            id=14   [slave  pointer  (2)]
⎜   ↳ Wacom HID 4841 Pen stylus                 id=11   [slave  pointer  (2)]
⎜   ↳ Wacom HID 4841 Pen eraser                 id=21   [slave  pointer  (2)]
⎜   ↳ MOSART Semi. 2.4G RF Keyboard & Mouse     id=22   [slave  pointer  (2)]
⎜   ↳ MOSART Semi. 2.4G RF Keyboard & Mouse Consumer Control    id=24   [slave  pointer  (2)]
⎜   ↳ Wacom HID 4841 Finger touch               id=12   [slave  pointer  (2)]
⎜   ↳ DELL0823:00 044E:120A Mouse               id=13   [slave  pointer  (2)]

I tried disabling certain other pointers but with no luck.

6

Update: It was actually a “hardware” issue, which was resolved by removing and re-inserting the batteries into the pen. See here: https://github.com/linuxwacom/wacom-hid-descriptors/issues/49#issuecomment-694853480

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