Gfilui

I am using Lenovo x1 carbon 3rd generation with ubuntu 18.04, The touch pad is behaving weird like, If you drag the pointer down to a specific point and removes the finger from the touchpad then the pointer jumps to a random position.

An example will be closing a browser tab, Drag the pointer x and remove the finger off the pad, The pointer jumps to a random position.

Is it normal, Or is there anything which can help around.

Thanks

The same problem forced me to switch to Synaptics driver. It's deprecated but this fact has never affected my experience.

To make your touchpad stop shaking and become more precise you may use my solution:

In /usr/share/X11/xorg.conf.d directory I have 40-libinput.conf with the following content:

# Match on all types of devices but joysticks
Section "InputClass"
 Identifier "libinput pointer catchall"
 MatchIsPointer "on"
 MatchDevicePath "/dev/input/event*"
 Driver "libinput"
EndSection

Section "InputClass"
 Identifier "libinput keyboard catchall"
 MatchIsKeyboard "on"
 MatchDevicePath "/dev/input/event*"
 Driver "libinput"
EndSection

Section "InputClass"
 Identifier "libinput touchpad catchall"
 MatchIsTouchpad "on"
 MatchDevicePath "/dev/input/event*"
 Driver "libinput"
EndSection

Section "InputClass"
 Identifier "libinput touchscreen catchall"
 MatchIsTouchscreen "on"
 MatchDevicePath "/dev/input/event*"
 Driver "libinput"
EndSection

Section "InputClass"
 Identifier "libinput tablet catchall"
 MatchIsTablet "on"
 MatchDevicePath "/dev/input/event*"
 Driver "libinput"
EndSection

And 70-synaptics.conf with:

# Example xorg.conf.d snippet that assigns the touchpad driver
# to all touchpads. See xorg.conf.d(5) for more information on
# InputClass.
# DO NOT EDIT THIS FILE, your distribution will likely overwrite
# it when updating. Copy (and rename) this file into
# /etc/X11/xorg.conf.d first.
# Additional options may be added in the form of
# Option "OptionName" "value"
#
Section "InputClass"
 Identifier "touchpad catchall"
 Driver "synaptics"
 MatchIsTouchpad "on"
 Option "TapButton1" "1"
 Option "TapButton2" "3"
 Option "TapButton3" "2"
 Option "PalmDetect" "1"
 Option "PalmMinWidth" "8"
 Option "PalmMinZ" "100"
 Option "VertScrollDelta" "-125"
 Option "HorizTwoFingerScroll" "on"
 Option "HorizScrollDelta" "-125"
# This option is recommend on all Linux systems using evdev, but cannot be
# enabled by default. See the following link for details:
# http://who-t.blogspot.com/2010/11/how-to-ignore-configuration-errors.html
 MatchDevicePath "/dev/input/event*"
EndSection

Section "InputClass"
 Identifier "touchpad ignore duplicates"
 MatchIsTouchpad "on"
 MatchOS "Linux"
 MatchDevicePath "/dev/input/mouse*"
 Option "Ignore" "on"
EndSection

# This option enables the bottom right corner to be a right button on clickpads
# and the right and middle top areas to be right / middle buttons on clickpads
# with a top button area.
# This option is only interpreted by clickpads.
Section "InputClass"
 Identifier "Default clickpad buttons"
 MatchDriver "synaptics"
 Option "SoftButtonAreas" "50% 0 82% 0 0 0 0 0"
 Option "SecondarySoftButtonAreas" "58% 0 0 15% 42% 58% 0 15%"
EndSection

# This option disables software buttons on Apple touchpads.
# This option is only interpreted by clickpads.
Section "InputClass"
 Identifier "Disable clickpad buttons on Apple touchpads"
 MatchProduct "Apple|bcm5974"
 MatchDriver "synaptics"
 Option "SoftButtonAreas" "0 0 0 0 0 0 0 0"
EndSection

If this file does not exist, you should create it. Notice that the number before synaptics must be greater than the number before libinput.

You should not delete 40-libinput.conf because in this case touchpad won't work at all.

P.S. A good article in which you can find out how to configure Synaptics file - https://wiki.archlinux.org/index.php/Touchpad_Synaptics