Synaptics Touchpad on Linux

So you've landed here, and I feel you. You run Linux or BSD on an outdated machine with an outdated piece of Touchpad that just won't work properly. Every stackoverflow answer is wrong and doesn't work, you're stuck, and you have no idea how to fix it.

But don't give up, this guide is meant exactly for you to learn about the inner workings of the Synaptics Touchpad driver and how to actually make it work without issues. Because it's actually a sophisticated device that just needs some configuration love in order to make it enjoyable to use.

Configure Xorg/X11 Synaptics Driver

On your Linux or BSD distribution, you'll have to add a configuration file for the synaptics driver. For ArchLinux, this file has to be stored at the path /etc/X11/xorg.conf.d/70-synaptics.conf .

In order to get started, there are some quirks here. The newer driver libinput replaced the Synaptics driver, we all are aware of that. But that also means that the Synaptics driver needs to catch all events from the legacy /dev/input/event* events from the Linux kernel.

Additionally the Driver has to ignore emulated Mouse pointers coming from the Touchpad, otherwise we'll end up with a messed up behaviour that will shift the Mouse relatively instead of absolutely to the Touchpad corners.

In the 70-synaptics.conf , we start with the following :

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

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

(...)
					

List available Synaptics Driver Options and Parameters

If you're using the Synaptics Touchpad driver already, you'll also have the synclient tool available that you can use to show all settings and further parameters to configure the touchpad driver's Xorg config files.

[$] synclient -l;

Parameter settings:
    LeftEdge     = 1310
    RightEdge    = 4826
    TopEdge      = 2220
    BottomEdge   = 4636
    (...)
					

Use Edges for Scrolling with the Synaptics Touchpad

The Boundaries are easily defined once you understood that there are two independent areas that you can define.

• The *Edge Options are related to Edge-based Scrolling.
• The Area*Edge Options are related to Touches and Two-Finger Scrolling.

If the Touch Area exceeds the Edges, it's recognized as a Touch and not an Edge Tap. So if Edge-based Scrolling is desired, the Edges of the Touch Area are not allowed to exceed the *Edge Edges.

Example for an Edge-based Scrolling Area that has two separate Scrolling Areas on the Right (for vertical One-Finger scrolling) and Top (for horizontal One-Finger scrolling) :

When running synclient -l , the defaulted areas give a hint on how large the coordinate system of the installed Synaptics Touchpad is. In the example case, it's 5112 in X-direction and 4832 in Y-direction.

# Inside /etc/X11/xorg.conf.d/70-synaptics.conf

Section "InputClass"
	MatchDriver "synaptics"

	# Outer Area (for Edge Scrolling)
	Option "LeftEdge" "0"
	Option "RightEdge" "4826"
	Option "TopEdge" "2220"
	Option "BottomEdge" "4832"

	# Enable Edge Scrolling
	Option "VertEdgeScroll" "1"
	Option "HorizEdgeScroll" "1"

EndSection
					

Use only Touches and Gestures with the Synaptics Touchpad

As mentioned in the previous paragraph, the Synaptics Touchpad differs between the *Edge Options that define the older Edge One-Finger based Scrolling, and the newer Area*Edge Options that can optionally be combined with the nwere Two-Finger based Scrolling.

The Area Options define the Touch/Tap areas on the Touchpad, so that it's possible to just instead use Two-Finger Taps and Two-Finger Scrolling and/or Three-Finger Swipes and Middle Clicks.

When running synclient -l , the defaulted areas give a hint on how large the coordinate system of the installed Synaptics Touchpad is. In the example case, it's 5112 in X-direction and 4832 in Y-direction.

# Inside /etc/X11/xorg.conf.d/70-synaptics.conf

Section "InputClass"
	MatchDriver "synaptics"

	# Outer Area (for Edge Scrolling)
	Option "LeftEdge" "0"
	Option "RightEdge" "5112"
	Option "TopEdge" "0"
	Option "BottomEdge" "4832"

	# Disable Edge Scrolling
	Option "VertEdgeScroll" "0"
	Option "HorizEdgeScroll" "0"

	# Inner Area (for Touches and Taps)
	Option "AreaLeftEdge" "0"
	Option "AreaRightEdge" "5112"
	Option "AreaTopEdge" "0"
	Option "AreaBottomEdge" "4832"

EndSection
					

Detect Taps and Detect Resting Hand Palms

By default, the Tap Buttons of the Synaptics Touchpad driver are messed up, and you probably want to change the Options related to them in order to have a correctly working Two-Finger Rightclick and Three-Finger Swipe .

If the Laptop has also a Clickpad (e.g. like Thinkpads have) it's also possible to disable it via the Clickpad Option. The PalmDetect Option is there to have you covered during typing on the Keyboard.

As every Hand Palm is different in size and weight, there's also a possibility to tweak the detection of it. If your Hand isn't detected properly or sometimes positions the mouse cursor or taps accidentially, the PalmMinWidth and PalmMinZ (pressure) Options can be tweaked.

Note that even the old Thinkpad Touchpads in the T400 series had support for Pressure-based motions in Z-direction, so it's very likely that later models of Laptops support it, too.

# Inside /etc/X11/xorg.conf.d/70-synaptics.conf

Section "InputClass"
	MatchDriver "synaptics"

	# Disable annoying Clickpad on Thinkpad Touchpad
	Option "Clickpad" "0"

	# Palm Detection
	Option "PalmDetect" "1"
	Option "PalmMinWidth" "10"
	Option "PalmMinZ" "200"

	# Expected Tap Button Behaviours
	Option "TouchpadOff" "0"
	Option "TapButton1" "1" # One-Finger Left Click
	Option "TapButton2" "3" # Two-Finger Right Click
	Option "TapButton3" "2" # Three-Finger Swipe/Middle Click

EndSection
					

Disable Cursor Acceleration

In order to have a more predictable behaviour of the Touchpad, it's possible to set the MinSpeed and MaxSpeed to the same maximal value of 2.0 , so that the speed isn't accelerated and therefore it's more predictable where the mouse cursor stops.

# Inside /etc/X11/xorg.conf.d/70-synaptics.conf

Section "InputClass"
	MatchDriver "synaptics"
	Option "MinSpeed" "2.0"
	Option "MaxSpeed" "2.0"
EndSection
					

Enable Horizontal and Vertical Two-Finger Scrolling

In order to setup Horizontal Scrolling and Vertical Scrolling , it's necessary to disable the Edge Scrolling first. Otherwise the dedicated areas on the outside of your Touchpad will be used for Scrolling, and that is unpredictable when using Two-Finger gestures in parallel.

The relevant ScrollDelta properties are calculated in an inverted manner, so they have to be set to a Number that's lower than 0 in order to emulate a Natural Scrolling behaviour.

# Inside /etc/X11/xorg.conf.d/70-synaptics.conf

Section "InputClass"
	MatchDriver "synaptics"

	# Vertical Two-Finger Scrolling
	Option "VertEdgeScroll" "0"
	Option "VertTwoFingerScroll" "1"
	Option "VertScrollDelta" "-111"

	# Horizontal Two-Finger Scrolling
	Option "HorizEdgeScroll" "0"
	Option "HorizTwoFingerScroll" "1"
	Option "HorizScrollDelta" "-111"

EndSection
					

Modify Click Times and Tap Times

The Synaptics Touchpad driver also supports the configuration of the time deltas after which a Tap and then the Click is recognized. Depending on whether you want the Middle Mouse Button (emulated Click on a Scroll Wheel of a Mouse) to function, these times can sometimes interfere with the Firmware's defaulted settings.

The time-related Options are all defined in Milliseconds .

# Inside /etc/X11/xorg.conf.d/70-synaptics.conf

Section "InputClass"
	MatchDriver "synaptics"

	# Tap after 180ms
	Option "MaxTapTime" "180"
	Option "MaxDoubleTapTime" "180"
	Option "SingleTapTimeout" "180"

	# Click after 100ms, meaning
	# -> button-down is fired after Max(Double)TapTime
	# -> button-up is fired after Max(Double)TapTime + ClickTime
	Option "ClickTime" "100"

	# Emulate Middle Mouse Button (Button 3)
	Option "EmulateMidButtonTime" "75"

	# Cancel Drag after 5 Seconds
	Option "LockedDragTimeout" "5000"

EndSection
					

Corners as Mouse Buttons

There's also the possibility to use the Synaptics Touchpad in order to have the emulated mouse buttons available as taps on specific corners of the Touchpad.

The Number identifiers for the Option values are the same, but this example config should clear things up :

# Inside /etc/X11/xorg.conf.d/70-synaptics.conf

Section "InputClass"
	MatchDriver "synaptics"

	Option "LTCornerButton" "1" # Left Top Corner is Left-Click
	Option "RTCornerButton" "2" # Right Top Corner is Right-Click
	Option "RBCornerButton" "0" # Right Bottom Corner is disabled
	Option "LBCornerButton" "3" # Left Bottom Corner is Middle-Click

EndSection
					

Enable Pressure Motion on Synaptics Touchpads

The Synaptics Touchpad driver also supports Pressure Motion, which means that when pressing the Touchpad with more force, the mouse cursor will move faster. If the Touchpad is pressed with less force, the mouse cursor will move slower.

In between the PressureMotionMinZ and PressureMotionMaxZ range, the speed of the cursor is incremented/decremented linearly.

# Inside /etc/X11/xorg.conf.d/70-synaptics.conf

Section "InputClass"
	MatchDriver "synaptics"

	# Minimum and maximum pressure values
	Option "PressureMotionMinZ" "30"
	Option "PressureMotionMaxZ" "160"

	# Double the cursor speed with high pressure
	Option "PressureMotionMinFactor" "1.0"
	Option "PressureMotionMaxFactor" "2.0"

EndSection
					

Fix Synaptics Driver on Broadcom Touchpads

There's a difference from the Broadcom BCM5974 chipsets that are used in older Apple Macbooks or Apple Macbook Pros. Those have wrong SoftButtonAreas configured by default, so they need to be corrected.

# Inside /etc/X11/xorg.conf.d/70-synaptics.conf

Section "InputClass"

	Identifier "disable clickpad buttons on Apple touchpads"
	MatchDriver "synaptics"
	MatchProduct "Apple|bcm5974"

	Option "SoftButtonAreas" "0 0 0 0 0 0 0 0"

EndSection
					

Reference Synaptics Touchpad Configuration

That's pretty much it. I've skipped the Circular Scrolling settings because they were buggy on the Synaptics Touchpads I've used.

If you're in doubt, use synclient -l and use man synaptics because it's actually documented in much detail how the Options and Parameters interact with each other.

In case you missed something in between the lines, I've added my minimal config file that works without issues. You can use this to get to a starting point that you can incrementally modify to fit your needs.

• 70-synaptics.conf