Arch Linux

Iusildra

Member

Registered: 2018-08-21

Posts: 2

[Libinput] Touchscreen bug / Non-existing instance

Hi,
After a boot or reboot, the touchscreen works, but it stops working most often after I've suspended the cpu (closing the laptop, sysemctl suspend etc...) or suddenly, just like that
So I check my input devices with libinput list-devices and xinput list

After I've entered the commands, I encountered something strange:
When the touchscreen worked well, I got this:

[root@Arch lucas]# xinput list
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ SYNA7508:00 06CB:12A4                     id=12   [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad                id=14   [slave  pointer  (2)]

And after the bug, that:

[root@Arch lucas]# xinput list
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ SYNA7508:00 06CB:12A4                     id=12   [slave  pointer  (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad                id=14   [slave  pointer  (2)]
⎜   ↳ SYNA7508:00 06CB:12A4 Pen Pen (0)         id=17   [slave  pointer  (2)]

We have one instance that appeared by magic. And of course (otherwise it wouldn't be fun), Pen Pen is not listed in libinput list-devices.

[root@Arch lucas]# libinput list-devices | grep 'SYNA7508:00 06CB:12A4 Pen Pen (0)'
[root@Arch lucas]#
[root@Arch lucas]# libinput list-devices | grep 'SYNA7508:00 06CB:12A4 Pen Pen'
[root@Arch lucas]# 

But that was before. Now as I'm writing this post, I have two instances of SYNA7508:00 06CB:12A4 Pen Pen (0)

Yet, I can't say that the touchscreen is not working at all because when I taped the touchscreen while libinput debug-events was on I got this:

 
event7   TOUCH_DOWN        +8.34s      0 (0) 53.63/70.97 (139.00/104.40mm)
event7   TOUCH_FRAME       +8.34s
event7   TOUCH_UP          +8.37s
event7   TOUCH_FRAME       +8.37s

So the tap on touchscreen is detected but I can't use it.
PS: Someone told me that the source of my bug wasn't Pen Pen, yet I don't understand why this instance have appeared, even if it wasn't listed in libinput list-devices

Edit 1:
I can make my touchscreen works again by using

xinput disable <touchscreen's id>
xinput enable <touchscreen's id>

Thanks for your help

Last edited by Iusildra (2018-08-25 19:36:56)