Synaptics

synaptics is the open source input driver for Synaptics and ALPS touchpads.

Installation

Kernel

Activate the following kernel options:

KERNEL

Device Drivers  --->
   Input device support  --->
      <*>   Event interface
      [*]   Mice  --->
         <*>   PS/2 mouse

Note
Additional drivers may be necessary under the Mice menu to support the touchpad. e.g. "Synaptics PS/2 mouse protocol extension". The touchpad may also be USB, not PS/2. When in doubt, select multiple drivers and check what the kernel uses later with lspci -k.

Driver

FILE /etc/portage/make.confSet INPUT_DEVICES

INPUT_DEVICES="synaptics libinput"

After setting the INPUT_DEVICES variable remember to update the system using the following command so the changes take effect:

root #emerge --ask --changed-use --deep @world

Configuration

The driver has a lot options for tuning. See the synaptics(5) man page for more information.

Fixed configuration

Referring to xorg.conf there should have a /etc/X11/xorg.conf.d directory on the system. If there is none create one:

root #mkdir /etc/X11/xorg.conf.d

Configure file /etc/X11/xorg.conf.d/50-synaptics.conf as in the example below:

FILE /etc/X11/xorg.conf.d/50-synaptics.conf

Section "InputClass"
        Identifier "touchpad catchall"
        Driver "synaptics"
        MatchIsTouchpad "on"
        Option "VertEdgeScroll" "on"
        Option      "CircularScrolling"         "on"
        Option      "VertScrollDelta"          "-111"
        Option      "HorizScrollDelta"         "-111"
        Option      "TapButton1"       	          "1"
EndSection

Configuration at runtime

Enable the above option to be able to configure the driver also at runtime. Changes at runtime will be lost with the next start of the X server. Add changes to the above config file to persist desired settings.

Configure the driver with the program synclient. Some examples:

List all parameters:

user $synclient -l

Cut the right side of the touch area to expand the vertical scroll area:

user $synclient RightEdge=5000

Finding the right edge parameter:

user $synclient -m 50

Disable the mouse click function:

user $synclient MaxTapTime=0

Finally, dump the handpicked configuration to the 99-synaptics file pasting output of the following command inside the InputClass section:

user $synclient -l | sed -e '1d' -e 's/^ \+/Option\t"/g' -e 's/ \+= /"\t"/g' -e 's/$/"/g'

Alternatively there is the KDE systemsettings module kde-misc/synaptiks:

root #emerge --ask kde-misc/synaptiks

Troubleshooting

Touchpad is not recognized

If the touchpad does not show in either lsusb nor lspci, that might be due to the PS/2 controller and how it is handled by the kernel. One indication is if dmesg returns sometings along the lines of:

user $dmesg | grep i8042

i8042: PNP: PS/2 appears to have AUX port disabled, if this is incorrect please boot with i8042.nopnp

That AUX port is where the touchpad is connected. Try adding the following to the kernel command line, e.g. in /etc/default/grub:

FILE /etc/default/grub

GRUB_CMDLINE_LINUX_DEFAULT="... i8042.noloop i8042.nomux i8042.nopnp i8042.reset ..."

Now, update your grub.cfg:

root #grub-mkconfig -o /boot/grub/grub.cfg

If, after rebooting with these parameters, a generic Logitech PS/2 mouse input device is detected, the appropriate PS/2 extension driver may be necessary in the Kernel config:

KERNEL

Device Drivers  --->
   Input device support  --->
      <*>   Event interface
      [*]   Mice  --->
         <*>   PS/2 mouse
            [ /*]   Elantech PS/2 protocol extension
            [ /*]   Sentelic Finger Sensing Pad PS/2 protocol extension
            [ /*]   eGalax TouchKit PS/2 protocol extension

After rebooting, the touchpad should be recognized correctly.

See also

• libinput — an input device driver for Wayland compositors and X.org window system.
• Xorg/Using the numeric keyboard keys as mouse — XOrg comes with built-in mouse emulation using the keyboards numeric keypad.