Bug 98733

Summary:	Touchpad gets a stuck button if used while TrackPoint button is down
Product:	Wayland	Reporter:	Anders Kaseorg <andersk>
Component:	libinput	Assignee:	Wayland bug list <wayland-bugs>
Status:	RESOLVED DUPLICATE	QA Contact:
Severity:	normal
Priority:	medium	CC:	peter.hutterer
Version:	unspecified
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description Anders Kaseorg 2016-11-15 04:20:18 UTC

I have a ThinkPad Yoga 14 with both a touchpad and physical buttons for the TrackPoint, and I like to use them at the same time, but recently I’ve found that this often causes a button to get temporarily stuck in the down state.

Here’s what this looks like in libinput-debug-events (event8 = physical buttons, event9 = touchpad):

(I rest my finger on the touchpad)
event9 	POINTER_MOTION    +1.88s	  0.25/  0.00
event9 	POINTER_MOTION    +1.89s	  0.12/  0.00
(I depress a physical button)
event8 	POINTER_BUTTON    +2.00s	BTN_LEFT (272) pressed, seat count: 1
event9 	POINTER_BUTTON    +2.00s	BTN_LEFT (272) pressed, seat count: 2
(I pick up my finger from the touchpad; no output)
(I release the physical button)
event8 	POINTER_BUTTON    +2.87s	BTN_LEFT (272) released, seat count: 1
(At this point my fingers are not touching anything.)
(I rest my finger on the touchpad, which now finally sends its button release.)
event9 	POINTER_BUTTON    +5.69s	BTN_LEFT (272) released, seat count: 0
event9 	POINTER_MOTION    +5.76s	  0.20/ -0.61
event9 	POINTER_MOTION    +5.77s	  1.00/ -1.53

I’m using xserver-xorg-input-libinput 0.19.0-1 and libinput10 1.4.3-0ubuntu1 on Ubuntu 17.04.

Comment 1 Peter Hutterer 2016-11-15 04:58:57 UTC


*** This bug has been marked as a duplicate of bug 96267 ***

Comment 2 Anders Kaseorg 2016-11-15 05:09:38 UTC

By marking this as a duplicate, do you mean to suggest that libinput is getting bad data from the kernel?  I don’t think that’s the case.  evemu-record /dev/input/event9 shows that the kernel is well aware that the touchpad is being released, whether or not a physical button is held down.

Comment 3 Peter Hutterer 2016-11-15 05:17:44 UTC

yeah, I thought it was the same issue. the ps2 loses sync and we miss these. Is that not the case here? Do you get the right button events at all times?

Comment 4 Anders Kaseorg 2016-11-15 05:22:56 UTC

Oh wait, I should have looked at that more closely.  evemu-record does show EV_KEY / BTN_LEFT 1 when the button gets stuck, and EV_KEY / BTN_LEFT 0 when it is released, so perhaps this is a kernel bug after all.

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