Bug 23585

Summary:	drawing tablet no longer working - formerly a wizardpen device
Product:	Mageia	Reporter:	Richard Walker <richard.j.walker>
Component:	RPM Packages	Assignee:	Kernel and Drivers maintainers <kernel>
Status:	RESOLVED INVALID	QA Contact:
Severity:	normal
Priority:	Normal	CC:	marja11, thierry.vignaud
Version:	6
Target Milestone:	---
Hardware:	All
OS:	Linux
Whiteboard:
Source RPM:	x11-driver-input-libinput-0.25.1-2.mga6.src.rpm	CVE:
Status comment:

Description Richard Walker 2018-09-16 14:02:33 CEST

Description of problem:
The device is a UC-LOGIC Tablet WP5540U which has worked for years in Mandrake/Mandriva/Mageia. It last worked successfully in Mageia 6 a few weeks ago.

lsusb reports the device as:
Bus 007 Device 009: ID 5543:0004 UC-Logic Technology Corp. Tablet WP5540U

UC-LOGIC references in /var/log/Xorg.0.log show successful identification and enumeration of the attached device and then the libinput failure:

[   261.987] (II) config/udev: Adding input device UC-LOGIC Tablet WP5540U Pen (/dev/input/mouse2)
[   261.988] (II) config/udev: Adding input device UC-LOGIC Tablet WP5540U Mouse (/dev/input/mouse3)
[   262.051] (II) config/udev: Adding input device UC-LOGIC Tablet WP5540U Mouse (/dev/input/event21)
[   262.051] (**) UC-LOGIC Tablet WP5540U Mouse: Applying InputClass "libinput pointer catchall"
[   262.051] (II) Using input driver 'libinput' for 'UC-LOGIC Tablet WP5540U Mouse'
[   262.051] (**) UC-LOGIC Tablet WP5540U Mouse: always reports core events
[   262.104] (II) event21 - (II) UC-LOGIC Tablet WP5540U Mouse: (II) is tagged by udev as: Mouse
[   262.104] (II) event21 - (II) UC-LOGIC Tablet WP5540U Mouse: (II) device is a pointer
[   262.104] (II) event21 - (II) UC-LOGIC Tablet WP5540U Mouse: (II) device removed
[   262.123] (II) XINPUT: Adding extended input device "UC-LOGIC Tablet WP5540U Mouse" (type: MOUSE, id 17)
[   262.123] (**) UC-LOGIC Tablet WP5540U Mouse: (accel) selected scheme none/0
[   262.123] (**) UC-LOGIC Tablet WP5540U Mouse: (accel) acceleration factor: 2.000
[   262.123] (**) UC-LOGIC Tablet WP5540U Mouse: (accel) acceleration threshold: 4
[   262.175] (II) event21 - (II) UC-LOGIC Tablet WP5540U Mouse: (II) is tagged by udev as: Mouse
[   262.175] (II) event21 - (II) UC-LOGIC Tablet WP5540U Mouse: (II) device is a pointer
[   262.176] (II) config/udev: Adding input device UC-LOGIC Tablet WP5540U Pen (/dev/input/event20)
[   262.176] (**) UC-LOGIC Tablet WP5540U Pen: Applying InputClass "libinput tablet catchall"
[   262.176] (II) Using input driver 'libinput' for 'UC-LOGIC Tablet WP5540U Pen'
[   262.176] (**) UC-LOGIC Tablet WP5540U Pen: always reports core events
[   262.176] (II) event20 - (II) UC-LOGIC Tablet WP5540U Pen: (II) is tagged by udev as: Tablet
[   262.176] (EE) event20 - (EE) UC-LOGIC Tablet WP5540U Pen: (EE) libinput bug: device does not meet tablet criteria. Ignoring this device.
[   262.176] (II) event20 - (II) UC-LOGIC Tablet WP5540U Pen: (II) device is a tablet
[   262.193] (EE) libinput: UC-LOGIC Tablet WP5540U Pen: Failed to create a device for /dev/input/event20
[   262.193] (EE) PreInit returned 2 for "UC-LOGIC Tablet WP5540U Pen"


Version-Release number of selected component (if applicable):


How reproducible:
It has failed to function after all attempts since about 4-6 weeks ago. I have tried both booting while connected and hot-plugging after boot.

Steps to Reproduce:
1.
2.
3.

Comment 1 Marja Van Waes 2018-09-18 15:22:07 CEST

Assigning to the kernel & drivers maintainers, CC'ing the registered maintainer.

Assignee: bugsquad => kernel
CC: (none) => marja11, thierry.vignaud

Comment 2 Richard Walker 2018-09-18 18:59:57 CEST

I tried to find out what specific bug the libinput people know about, but haven't yet conquered, to get this type of tablet working. All I discovered was I appear not to be alone. From information gleaned from https://wayland.freedesktop.org/libinput/doc/latest/tools.html I ran the libinput-list-devices command and got this info from "the horse's mouth"

Device:           UC-LOGIC Tablet WP5540U Mouse
Kernel:           /dev/input/event8
Group:            7
Seat:             seat0, default
Capabilities:     pointer 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      disabled
Nat.scrolling:    disabled
Middle emulation: disabled
Calibration:      n/a
Scroll methods:   button
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   flat *adaptive
Rotation:         n/a


It doesn't get mne any further, but it shows libinput is being a bit schizophrenic about this. On the one hand it knows

Comment 3 Richard Walker 2018-09-18 19:01:50 CEST

oops, keyboard malfunction. To continue....

It know about the tablet's pointer capability, but on the other hand it thinks this is not enough to meet its "tablet criteria".

Comment 4 Richard Walker 2018-10-24 01:43:54 CEST

It has been a while since I discovered a workaround which will probably prove to be the solution. It took a couple of weeks to figure it out, but I think I should just accept that libinput is not the all-singing, all-dancing input driver I thought it was. 

Fortunately evdev still works for this tablet, and possibly others which libinput doesn't regard as being up to its standards. I found a config snippet for xorg.conf which seems to work for the pen and tablet mouse, though I haven't yet figured out how to switch it from screen to window coordinates.

In light of this I will close the bug now.

Status: NEW => RESOLVED
Resolution: (none) => INVALID