0

I have installed Ubuntu 18.04 on Lenovo Ideapad L340. Tapping on the touchpad does not work properly. For most of the time, it works very well but sometimes it does not work and I have to tap again (It is not too much maybe 5 or 6 times within some hours). I tried to change some settings in the touchpad to see if it can affect on the problem. For example there are two options in output of xinput list-props. The first one is libinput Tapping Enabled (273): 1 and the second one is: libinput Tapping Enabled Default (274): 0. I tried to enable the second option by this command xinput set-prop "Synaptics TM3336-004" "libinput Tapping Enabled Default" 1 but I got this error:

X Error of failed request:  BadAccess (attempt to access private       resource denied)
Major opcode of failed request:  131 (XInputExtension)
Minor opcode of failed request:  57 ()
Serial number of failed request:  20
Current serial number in output stream:  21

1) Does this error show anything about this problem?
2) Which options in output of the command xinput list-props can affect on this problem?
3) Is this a bug?
The output of xinput is :

⎡ Virtual core pointer                      id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Synaptics TM3336-004                      id=10   [slave  pointer  (2)]
⎣ Virtual core keyboard                     id=3    [master keyboard (2)]
↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
↳ Video Bus                                 id=6    [slave  keyboard (3)]
↳ Video Bus                                 id=7    [slave  keyboard (3)]
↳ Power Button                              id=8    [slave  keyboard (3)]
↳ Integrated Camera: Integrated C           id=9    [slave  keyboard (3)]
↳ Ideapad extra buttons                     id=11   [slave  keyboard (3)]
↳ AT Translated Set 2 keyboard              id=12   [slave  keyboard (3)]

The output of command xinput list-props 10 is :

Device 'Synaptics TM3336-004':
Device Enabled (136):   1
Coordinate Transformation Matrix (138): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Tapping Enabled (273): 1
libinput Tapping Enabled Default (274): 0
libinput Tapping Drag Enabled (275):    1
libinput Tapping Drag Enabled Default (276):    1
libinput Tapping Drag Lock Enabled (277):   0
libinput Tapping Drag Lock Enabled Default (278):   0
libinput Tapping Button Mapping Enabled (279):  1, 0
libinput Tapping Button Mapping Default (280):  1, 0
libinput Natural Scrolling Enabled (281):   1
libinput Natural Scrolling Enabled Default (282):   0
libinput Disable While Typing Enabled (283):    0
libinput Disable While Typing Enabled Default (284):    1
libinput Scroll Methods Available (285):    1, 1, 0
libinput Scroll Method Enabled (286):   0, 0, 0
libinput Scroll Method Enabled Default (287):   1, 0, 0
libinput Click Methods Available (288): 1, 1
libinput Click Method Enabled (289):    1, 0
libinput Click Method Enabled Default (290):    1, 0
libinput Middle Emulation Enabled (291):    0
libinput Middle Emulation Enabled Default (292):    0
libinput Accel Speed (293): 0.622378
libinput Accel Speed Default (294): 0.000000
libinput Left Handed Enabled (295): 0
libinput Left Handed Enabled Default (296): 0
libinput Send Events Modes Available (258): 1, 1
libinput Send Events Mode Enabled (259):    0, 0
libinput Send Events Mode Enabled Default (260):    0, 0
Device Node (261):  "/dev/input/event14"
Device Product ID (262):    1739, 33364
libinput Drag Lock Buttons (297):   <no items>
libinput Horizontal Scroll Enabled (298):

Thanks.

Tjax
  • 103
  • The properties ending with Default are not meant to be changed, they're there just for reference "what the default value was". About the tapping problem, first thing that comes to mind is to try out latest released libinput (which is 1.14.2 as of writing the words). There was new thumb detection code, which may or may not help. Other than that, you'd need to get a evemu-record of the problem when it happens, and report a bug. – Hi-Angel Oct 23 '19 at 20:50
  • 1
    @Hi-Angel, I could upgrade libinput. It does not changed actually I have that problem. There are two question I have 1) Do I need to install xf86-input-libinput as well. 2) There are a list of device which is output of this command sudo libinput list-devices. In this list one of the option for my touchpad is tap-to-click which is disabled but I can tap even though it is disabled. Should I enabled it and how? – Tjax Oct 26 '19 at 15:21
  • Oh, that's sad :c To answer your points: 1) It looks like an important package (unless you're running Wayland), but in the context the tapping problem: I doubt it's relevant. FWIW, anytime I was playing with libinput, I was only ever replacing libinput.so.10.13.0 file through sudo mv … with the one I compiled. 2. Oh, sorry, that's confusing. The utility shows default values rather than current ones. Disregard this output. Since you do use "tap-to-click", I doubt it may be disabled. – Hi-Angel Oct 26 '19 at 20:41
  • I sent an improvement to man libinput-list-devices since it's wasn't really clear; the note that libinput list-devices lists the default values is somewhere at the bottom, though it's one of the most important information for proper usage. – Hi-Angel Oct 26 '19 at 20:44
  • @Hi-Angel, I followed this answer: link to install libinput , There is one command which I am not sure what I have to do with. This is meson --prefix=/usr builddir/. When I upgrade libinput I did not change builddir but now I think I have to change it. Is it right? Should I use builddir or I have to give a path to it? Even though when I check the version of libinput it is newest version. Thanks – Tjax Oct 27 '19 at 04:57
  • You don't need to change builddir. It is a path to a directory into which compilation gonna place object files, binaries, etc. If you left it as is, this means that the meson command created a directory literally called builddir (which you can see by running ls ./ afterwards). Which is okay, why not. – Hi-Angel Oct 27 '19 at 08:10
  • @Hi-Angel, First of all thanks for your answers. All in all, do you think it is a bug? If I want to record this bug it is so difficult because on one hand it might not happen within 1 hour on the other hand it might happen twice within 5 minutes. It is very difficult to catch this bug. Is there any other thing according to you which can cause this problem? – Tjax Oct 27 '19 at 08:49
  • I think it's either a bug in libinput or a faulty touchpad. Btw, I did a search for word tap over libinput issues, and found this report, which sounds just like what you're describe, so maybe you may want to just add your +1 there. – Hi-Angel Oct 27 '19 at 09:10
  • @Hi-Angel, I will add mine there as well. How can I know it is faulty touchpad? I bought this system a month ago so I am in the period which I can return this system if I know it is faulty touchpad. – Tjax Oct 27 '19 at 09:28
  • Oh, it's actually simple: if you do evemu-record of the problem, and there was no events from the touchpad when a tap was missed, then you know that something is wrong with the touchpad. But don't bother, I doubt it could be the case since the linked report is still opened, and is the likely cause. – Hi-Angel Oct 27 '19 at 09:38
  • It is somehow impossible to know exactly when this happens. Is there any other way to know whether it is faulty touchpad ? For instance if I install windows in virtual box and it would work in windows I can draw conclusion it is not faulty touchapd right? Or maybe I have install windows seperately ? – Tjax Oct 27 '19 at 10:07
  • Yeah, you can do this too. Not with VirtualBox though, because to be sure you'll need the system to own the touchpad device, which is most easier to do by running a system on bare metal. – Hi-Angel Oct 27 '19 at 10:13
  • @Hi-Angel, Do you know how we can distinguish cursor movement from tap when we are recording withevemu-record? – Tjax Oct 27 '19 at 11:39
  • I think it's BTN_TOUCH 0 for when you put a finger followed by BTN_TOUCH 1 for when you removed the finger. The "tap" then is a concept inside libinput, where it, depending on the timing and coordinates of the touch, decides whether it was a tap. – Hi-Angel Oct 27 '19 at 12:23
  • Err, I mean, rather the reverse: 1 first, 0 second. – Hi-Angel Oct 27 '19 at 12:39
  • 1
    I did make a pattern like two cursor movements and one tap when I was recording. There is a tap in that recording file when it happens. So I do not think it is because of faulty touchpad. I follow that report bug to see what they can do about it. Thanks again – Tjax Oct 27 '19 at 12:43

0 Answers0