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I recently bought a Dell Inspiron laptop with Ubuntu Linux 14.04. I love using Linux and love the laptop, but I'm having trouble using the touchpad. Almost every time I I hover over something that I want to click the cursor jumps from where I want it to be to the far left of the screen, often down to the trash can. I'm wondering if the problem is due to the touchpad being oversensitive? Is there anything I can do?

Thanks,

Mx

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  • Have you checked synaptics settings and tried to decrease sensivity level?
    – benjamin button
    Jun 27, 2016 at 22:52
  • 1
    i don't know if your problem with speed of mouse or sensitivity anyway try change pointer speed from touch-pad & mouse on system settings i.stack.imgur.com/P2VcX.png
    – Mohamed Slama
    Jun 27, 2016 at 23:01
  • if it not working try this answer askubuntu.com/a/257844/464430
    – Mohamed Slama
    Jun 27, 2016 at 23:04
  • I have the same problem - are you using two hands on the trackpad, with one at the bottom left to click, and the other moving the mouse pointer?
    – Steve Kroon
    Jun 29, 2016 at 11:05
  • @MohamedSlama The concern does not seem to be the mouse/trackpad speed, but the sensitivity of the trackpad detecting touches/gestures which are not actually present, or are just slight brushes over the trackpad not meant to be interpreted as control.
    – Steve Kroon
    Jun 29, 2016 at 11:07

1 Answer 1

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3
+50

Assuming that this is due to spuriously brushing of yr touchpad as you type, you can modify certain parameters, provided yr touchpad driver is well installed.

First list Xorg input devices.
Results are for my present machine and will be different in yr case.

$ xinput --list  # list of Xorg session input devices
⎡ Virtual core pointer                 id=2 [master pointer (3)]
⎜   ↳ Virtual core XTEST pointer       id=4 [slave pointer (2)]
⎜   ↳ SynPS/2 Synaptics TouchPad       id=10 [slave pointer (2)]
⎜   ↳ PS/2 Generic Mouse               id=11 [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)]
    ↳ AT Translated Set 2 keyboard     id=9 [slave keyboard (3)]
    ↳ HP WMI hotkeys                   id=12 [slave keyboard (3)]

As you can see the present touchpad is identified as "SynPS/2 Synaptics TouchPad", next, to list yr touchpad properties, do in terminal:

$ xinput --list-props "SynPS/2 Synaptics TouchPad" | grep -e Finger
# Replace "SynPS/2 Synaptics TouchPad" above with yr own touchpad description.
Synaptics Finger (275): 25, 30, 0
Synaptics Two-Finger Pressure (281):    282
Synaptics Two-Finger Width (282):   7
Synaptics Two-Finger Scrolling (285):   1, 1

To understand the listed properties in detail, look up $ man 4 synaptics.
"Synaptics Finger" is the property of interest here:

  • Finger Low = 25 <- when finger pressure drops below this value, the driver counts it as a release.
  • Finger High = 30 <- when finger pressure goes above this value, the driver counts it as a touch.

As you see I like to keep my touchpad on the sensitive side. You, on the other hand, probably want to tweak "Finger High" and set it to a higher value, 50 or 60 or more. It depends as much on yr hardware as it does on you. You just need to experiment to fine tune yr hardware to yr specific needs. For instance:

 $ xinput --set-prop [device number] "Synaptics Finger" 25 60 0

In my use-case [device number] would correspond to 10 (as seen above from $ xinput --list) I increased the property "FingerHigh" above from 30 to 60. That translates in yr touchpad becoming less sensitive to spurious contacts.

Another way to configure yr device on the fly, without the need to restart yr Xorg session, is to use the cli utility synclient. It queries and modifies Synaptics driver options. This would allow you to adjust touchpad features that are not be exposed via the GUI. One would adjust parameters via a terminal:

 $ synclient FingerHigh=60

See $ man synclient for more details.

Although that type of configuration is not permanent and will not survive a reboot, it will help you in experimenting with values. Once you're satisfied with device behavior, you can edit the file /usr/share/X11/xorg.conf.d/50-synaptics.conf (<- this is my own configuration file's name; yr filename may differ.)

Section "InputClass"
    Identifier "touchpad"
    Driver "synaptics"
    MatchIsTouchpad "on"
        Option "..." "..."
        ...
        Option "FingerLow" "25"
        Option "FingerHigh" "60"
        ...
EndSection

That should make changes permanent across reboot, but those changes will likely be wiped out, when you perform a system or driver upgrade.

HTH. Feedback welcome.

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  • Thanks for the suggestions. I've fiddled with xinput and synclient a fair amount trying to fix this, but did not think it might be FingerLow/FingerHigh causing the problems. Will try this out, and see if it helps. @MadBow1 - can you give it a try as well?
    – Steve Kroon
    Jul 4, 2016 at 9:34
  • So fingerhigh=60 is very unresponsive, and shifting it to 40 does not resolve the issue. Trying 50 now; however, note that this is not caused by "spuriously brushing the keyboard as I type" - it happens when I am using both hands to navigate on the touchpad.
    – Steve Kroon
    Jul 4, 2016 at 9:41
  • ok. So you may have to look at other properties then. I had not realized that was yr problem. It would be advantageous for future readers of yr thread, that you make that clear in your original question. If you still have trouble, I can try to help you determine what correct property you should tweak. It is no FingerHigh to be sure.,
    – Cbhihe
    Jul 4, 2016 at 10:46
  • Not my original post, but it was clarified in the comments. As an update, symptoms persist with FingerHigh=50. It seems I want something else. Is there some bound on the distance between fingers for "two-finger" events - I see now that I can do two finger scrolling with my fingers on opposing sides of the touchpad, so I can imagine it is picking up the fingers of each hand as separate fingers, perhaps.
    – Steve Kroon
    Jul 4, 2016 at 13:15
  • SteveKroon: My bad. I was under the impression, while writing my pervious comment, that you were OP's author. I am waiting on @MadBow1's reply to see if my solution is suitable for her possible "sensitivity" issue ... Bear in mind that you aren't the author of this question. If you have a question of our own, or a purportedly different issue, post a new thread and I will try to help you as well. Anything else like having a solution solve yr specific problem instead of OP's would be thread-hijacking. Absolutely no offense intended here ! I can help you as well. :-)
    – Cbhihe
    Jul 5, 2016 at 7:45

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