Bug 96556

Summary:	Clevo W330AU multi-touch support
Product:	Wayland	Reporter:	Jaume <jaumet>
Component:	libinput	Assignee:	Wayland bug list <wayland-bugs>
Status:	RESOLVED NOTABUG	QA Contact:
Severity:	normal
Priority:	medium	CC:	peter.hutterer
Version:	1.3.0
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	libinput device propierties /sys/class/dmi/id/modalias output Swipe woth 3 fingers record with evemu

Description Jaume 2016-06-16 14:40:50 UTC

Created attachment 124561 [details]
libinput device propierties

It seems that libinput doesn't support my touchpad with multiouch gestures support. The computer case model is Clevo W330AU
link: http://www.clevo.com.tw/clevo_prodetail.asp?id=822&lang=en

When I debug the events and do swipe gesture with 3+ fingers it doesn't show any output. My current version of libinput is 1.3.1 in Arch Linux with Gnome 3.20.

Comment 1 Jaume 2016-06-16 14:41:40 UTC

Created attachment 124562 [details]
/sys/class/dmi/id/modalias output

Comment 2 Jaume 2016-06-16 14:44:33 UTC

The size of the touchpad area is 48mm(high)x90mm(width)

Comment 3 Peter Hutterer 2016-06-17 00:01:06 UTC

Record one of the gestures with evemu record please and attach it here, thanks

Comment 4 Jaume 2016-06-17 07:49:38 UTC

Created attachment 124568 [details]
Swipe woth 3 fingers record with evemu

Comment 5 Peter Hutterer 2016-06-19 23:48:16 UTC

This is the key here:
#   Property  type 3 (INPUT_PROP_SEMI_MT)

Semi-mt touchpads are those that can only provide us a bounding box of all  fingers rather than the actual position of each finger. In doing so, the resolution drops to about half whenever a second finger is on the touchpad (the third finger doesn't provide any position, it's just a bit that there is a third finger down). We had gestures for a while on semi-mt devices but because of the resolution issues we removed it, these devices simply aren't capable of enough precision to make gesture detection reliable. sorry.

so libinput not handling a three-finger gesture on these devices is correct behaviour.

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