Ubuntu – How to set up the touchpad of a Lenovo x121e

Summary from @thom comment, I've done this to make it work:

1. Open file /usr/share/X11/xorg.conf.d/50-synaptics.conf for edit.
2. Find Section "InputClass" which the following line is Identifier "Default clickpad buttons".
3. Edit option for SoftButtonAreas to values 64% 0 1 42% 36% 64% 1 42%, this is size of the right and middle button.

4. Enable option AreaBottomEdge and change value to 1, this will disable touchpad movement.

   If everything done right, your class should looks like:

   Section "InputClass"
       Identifier "Default clickpad buttons"
       MatchDriver "synaptics"
       Option "SoftButtonAreas" "64% 0 1 42% 36% 64% 1 42%"
       Option "AreaBottomEdge" "1"
   EndSection
   

5. Save file and re-login.

I use S440 btw, but I think this should work for all model that use buttonless touchpad.

You can fix it this way:

1. Run

sudo -H gedit /etc/default/grub

In the open window edit line

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

it should look this way

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i8042.nopnp"

Save file and run

sudo update-grub

2. Run

   echo "blacklist i2c_hid" | sudo tee /etc/modprobe.d/i2c-hid.conf
   sudo depmod -a
   sudo update-initramfs -u
   echo "synaptics_i2c" | sudo tee -a /etc/modules
   

3. Reboot.

Please be careful, do not retype these commands, but copy them and paste into the terminal, or you can break the whole system, if mistype.

This solution disables Plug & Play for i8042 devices, then disables i2c-hid module and enables synaptics_i2c instead or it.

Plug & Play triggers a wrong module for this device.