# Device quirks¶

libinput requires extra information from devices that is not always readily available. For example, some touchpads are known to have jumping cursors under specific conditions. libinput ships a set of files containting the so-called model quirks to provide that information. Model quirks are usually installed under /usr/share/libinput/<filename>.quirks and are standard .ini files. A file may contain multiple section headers ([some identifier]) followed by one or more MatchFoo=Bar directives, followed by at least one of ModelFoo=1 or AttrFoo=bar directive. See the quirks/README.md file in the libinput source repository for more details on their contents.

Warning

Model quirks are internal API and may change at any time. No backwards-compatibility is guaranteed.

For example, a quirks file may have this content to label all keyboards on the serial bus (PS/2) as internal keyboards:

[Serial Keyboards]
MatchUdevType=keyboard
MatchBus=serial
AttrKeyboardIntegration=internal


The model quirks are part of the source distribution and should never be modified locally. Updates to libinput may overwrite modifications or even stop parsing any property. For temporary local workarounds, see Installing temporary local device quirks.

Device quirks are parsed on libinput initialization. A parsing error in the device quirks disables all device quirks and may negatively impact device behavior on the host. If the quirks cannot be loaded, an error message is posted to the log and users should use the information in Debugging device quirks to verify their quirks files.

## Installing temporary local device quirks¶

The model quirks are part of the source distribution and should never be modified. For temporary local workarounds, libinput reads the /etc/libinput/local-overrides.quirks file. Users may add a sections to this file to add a device quirk for a local device but beware that any modification must be upstreamed or it may cease to work at any time.

Warning

Model quirks are internal API and may change at any time. No backwards-compatibility is guaranteed. Local overrides should only be used until the distribution updates the libinput packages.

The local-overrides.quirks file usually needs to be created by the user. Once the required section has been added, use the information from section Debugging device quirks to validate and test the quirks.

## Debugging device quirks¶

libinput provides the libinput quirks tool to debug the quirks database. This tool takes an action as first argument, the most common invocation is libinput quirks list to list model quirks that apply to one or more local devices.

$libinput quirks list /dev/input/event19$ libinput quirks list /dev/input/event0
AttrLidSwitchReliability=reliable


The device event19 does not have any quirks assigned.

When called with the --verbose argument, libinput quirks list prints information about all files and its attempts to match the device:

\$ libinput quirks list --verbose /dev/input/event0
quirks debug: /usr/share/share/libinput is data root
quirks debug: /usr/share/share/libinput/10-generic-keyboard.quirks
quirks debug: /usr/share/share/libinput/10-generic-lid.quirks
[...]
quirks debug: /usr/share/etc/libinput/local-overrides.quirks
quirks debug: /dev/input/event0: fetching quirks
quirks debug: [Serial Keyboards] (10-generic-keyboard.quirks) wants MatchBus but we don't have that
quirks debug: [Lid Switch Ct9] (10-generic-lid.quirks) matches for MatchName
quirks debug: [Lid Switch Ct10] (10-generic-lid.quirks) matches for MatchName
quirks debug: [Lid Switch Ct10] (10-generic-lid.quirks) matches for MatchDMIModalias
quirks debug: [Lid Switch Ct10] (10-generic-lid.quirks) is full match
quirks debug: property added: AttrLidSwitchReliability from [Lid Switch Ct10] (10-generic-lid.quirks)
quirks debug: [Aiptek No Tilt Tablet] (30-vendor-aiptek.quirks) wants MatchBus but we don't have that
[...]
quirks debug: [HUION PenTablet] (30-vendor-huion.quirks) wants MatchBus but we don't have that
quirks debug: [Logitech Marble Mouse Trackball] (30-vendor-logitech.quirks) wants MatchBus but we don't have that
quirks debug: [Logitech K400] (30-vendor-logitech.quirks) wants MatchBus but we don't have that
quirks debug: [Logitech K400r] (30-vendor-logitech.quirks) wants MatchBus but we don't have that
quirks debug: [Logitech K830] (30-vendor-logitech.quirks) wants MatchBus but we don't have that
quirks debug: [Logitech K400Plus] (30-vendor-logitech.quirks) wants MatchBus but we don't have that
quirks debug: [Logitech Wireless Touchpad] (30-vendor-logitech.quirks) wants MatchBus but we don't have that
quirks debug: [Microsoft Surface 3 Lid Switch] (30-vendor-microsoft.quirks) matches for MatchName
[...]
AttrLidSwitchReliability


Note that this is an example only, the output may change over time. The tool uses the same parser as libinput and any parsing errors will show up in the output.

## List of supported device quirks¶

This list is a guide for developers to ease the process of submitting patches upstream. This section shows device quirks supported in git commit 1ebdc60.

Warning

Quirks are internal API and may change at any time for any reason. No guarantee is given that any quirk below works on your version of libinput.

In the documentation below, the letters N, M, O, P refer to arbitrary integer values.

Quirks starting with Model* triggers implementation-defined behaviour for this device not needed for any other device. Only the more general-purpose Model* flags are listed here.

Indicates the touchpad has a drawn-on visible marker between the software buttons.

ModelTabletModeNoSuspend

Indicates that the device does not need to be suspended in Tablet mode switch handling.

ModelTabletModeSwitchUnreliable

Indicates that this tablet mode switch’s state cannot be relied upon.

ModelTrackball

Reserved for trackballs

ModelBouncingKeys

Indicates that the device may send fake bouncing key events and timestamps can not be relied upon.

AttrSizeHint=NxM, AttrResolutionHint=N

Hints at the width x height of the device in mm, or the resolution of the x/y axis in units/mm. These may only be used where they apply to a large proportion of matching devices. They should not be used for any specific device, override EVDEV_ABS_* instead, see Measuring and fixing touchpad ranges.

AttrTouchSizeRange=N:M, AttrPalmSizeThreshold=O

Specifies the touch size required to trigger a press (N) and to trigger a release (M). O > N > M. See Debugging touch size ranges for more details.

AttrTouchPressureRange=N:M, AttrPalmPressureThreshold=O, AttrThumbPressureThreshold=P

Specifies the touch pressure required to trigger a press (N) and to trigger a release (M), when a palm touch is triggered (O) and when a thumb touch is triggered (P). O > P > N > M. See Debugging touchpad pressure ranges for more details.

AttrLidSwitchReliability=reliable|write_open

Indicates the reliability of the lid switch. This is a string enum. Do not use “reliable” for any specific device. Very few devices need this, if in doubt do not set. See Lid switch handling for details.

AttrKeyboardIntegration=internal|external

Indicates the integration of the keyboard. This is a string enum. Generally only needed for USB keyboards.

AttrTPKComboLayout=below

Indicates the position of the touchpad on an external touchpad+keyboard combination device. This is a string enum. Don’t specify it unless the touchpad is below.

AttrEventCodeDisable=EV_ABS;BTN_STYLUS;EV_KEY:0x123;

Disables the evdev event type/code tuples on the device. Entries may be a named event type, or a named event code, or a named event type with a hexadecimal event code, separated by a single colon.

AttrPointingStickIntegration=internal|external

Indicates the integration of the pointing stick. This is a string enum. Only needed for external pointing sticks. These are rare.