Created attachment 122389 [details] evemu record Description: Sometimes the touch pad "tab" function stops working. See "steps to reproduce" for more details. The problem was introduced recently (before the system worked totally fine for over 6 months) Additional info: * libinput 1.2.2 * xf86-input-libinput 0.17.0 * system is a Lenovo Carbon X1, 2015 edition (3rd gen) * touchpad dimensions: 100mm w X 55mm h * kernel is 4.4.5.201603142220-1-grsec (Arch Linux) evemu recording: see attachement, the bug happens somewhere at the end, than I used the "scroll-around" work-around and got a tab-driven click working (see "Steps to reproduce" section) /sys/class/dmi/id/modalias: dmi:bvnLENOVO:bvrN14ET31W(1.09):bd06/26/2015:svnLENOVO:pn20BTS2EJ00:pvrThinkPadX1Carbon3rd:rvnLENOVO:rn20BTS2EJ00:rvrNotDefined:cvnLENOVO:ct10:cvrNone: xinput list-props: Device 'SynPS/2 Synaptics TouchPad': Device Enabled (138): 1 Coordinate Transformation Matrix (140): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000 libinput Tapping Enabled (277): 1 libinput Tapping Enabled Default (278): 0 libinput Tapping Drag Enabled (279): 1 libinput Tapping Drag Enabled Default (280): 1 libinput Tapping Drag Lock Enabled (281): 0 libinput Tapping Drag Lock Enabled Default (282): 0 libinput Accel Speed (283): 0.488789 libinput Accel Speed Default (284): 0.000000 libinput Natural Scrolling Enabled (285): 1 libinput Natural Scrolling Enabled Default (286): 0 libinput Send Events Modes Available (261): 1, 1 libinput Send Events Mode Enabled (262): 0, 0 libinput Send Events Mode Enabled Default (263): 0, 0 libinput Left Handed Enabled (287): 0 libinput Left Handed Enabled Default (288): 0 libinput Scroll Methods Available (289): 1, 1, 0 libinput Scroll Method Enabled (290): 1, 0, 0 libinput Scroll Method Enabled Default (291): 1, 0, 0 libinput Click Methods Available (292): 1, 1 libinput Click Method Enabled (293): 1, 0 libinput Click Method Enabled Default (294): 1, 0 libinput Disable While Typing Enabled (295): 1 libinput Disable While Typing Enabled Default (296): 1 Device Node (264): "/dev/input/event10" Device Product ID (265): 2, 7 libinput Drag Lock Buttons (297): <no items> libinput Horizonal Scroll Enabled (266): 1 Kernel synaptics boot log: psmouse serio1: synaptics: queried max coordinates: x [..5676], y [..4758] psmouse serio1: synaptics: queried min coordinates: x [1266..], y [1096..] psmouse serio1: synaptics: Touchpad model: 1, fw: 8.1, id: 0x1e2b1, caps: 0xf003a3/0x943300/0x12e800/0x10000, board id: 3072, fw id: 1795685 psmouse serio1: synaptics: serio: Synaptics pass-through port at isa0060/serio1/input0 Steps to reproduce: Work with the touchpad (tab and scroll around), after a while, the tab feature isn't working anymore, but scrolling and mouse movement seems to behave as expected. The logs show the following information /usr/lib/gdm/gdm-x-session[XXXX]: (EE) libinput bug: unexpected scroll event 0 in area state The tab feature can be restored using one of the following work-arounds: * go to the GNOME system settings and disable and re-enable the tab settings * try to "scroll" using 3 fingers, after some tries the libinput seems to behave normally again
Maybe related: sometimes 1-finger tabs (= "left mouse button click") are interpreted as 3-finger tabs (= "middle mouse button click"); yes, that's an "error" of 2 additional fingers. In this case the "do a 3 finger tab / scroll"-workaround also works. For both issues, I'm currently unable to eliminate that this is a hardware bug / defect.
Created attachment 122439 [details] Shorter dump Here is a shorter evemu "log" (only 18secs) which also produces the described bug.
looks like this is caused by the touch ending immediately after the series of pressure-only updates. the trick we do with t->dirty = false in a608d9dc2 would cause this event to be swallowed and that causes the issues. I'll look into a better fix for this.
Can you check if attachment 122601 [details] [review] from bug 94379 fixes this issue? Not 100% yet myself (I ran out of time for today)
commit bc17185f426dae7a1ea4df6ba3459083c2d51f9b Author: Peter Hutterer <peter.hutterer@who-t.net> Date: Tue Mar 29 13:34:00 2016 +1000 touchpad: only post motion events if we have motion
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