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 data/README.md file in the libinput source repository for more details on their contents.

Note
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.

Note
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 list-quirks tool to list and debug model quirks that apply to one or more local devices.

$ libinput list-quirks /dev/input/event19
Device has no quirks defined
$ libinput list-quirks /dev/input/event0
AttrLidSwitchReliability

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

$ libinput list-quirks --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.