I got a new T460s, and it seems that the input story is not yet fully fixed (See kernel bug #114321 for a related, but probably fixed bug).
I observe that when I move the cursor using the trackpoint and click the trackpoint button (below the space key) while doing so, the release event sometimes gets lost, and sometimes the press event. I test this using `xinput test 11`, but I can observe it more reliable in everyday use of the device.
Maybe the new code that erases “spurious” trackpoint events in 1.5 goes wrong?
This is kernel 4.8.0-rc8 from Debian, libinput 1.5, on X11.
I have reported this also at https://bugzilla.kernel.org/show_bug.cgi?id=176691 but maybe it is better here.
(I’ll try to follow up with better debugging information.)
~ $ xinput list
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ TPPS/2 IBM TrackPoint id=11 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
↳ Power Button id=6 [slave keyboard (3)]
↳ Video Bus id=7 [slave keyboard (3)]
↳ Sleep Button id=8 [slave keyboard (3)]
↳ Integrated Camera id=9 [slave keyboard (3)]
↳ AT Translated Set 2 keyboard id=10 [slave keyboard (3)]
↳ ThinkPad Extra Buttons id=12 [slave keyboard (3)]
~ $ xinput list-props 11
Device 'TPPS/2 IBM TrackPoint':
Device Enabled (139): 1
Coordinate Transformation Matrix (141): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Accel Speed (275): 0.000000
libinput Accel Speed Default (276): 0.000000
libinput Accel Profiles Available (277): 1, 1
libinput Accel Profile Enabled (278): 1, 0
libinput Accel Profile Enabled Default (279): 1, 0
libinput Natural Scrolling Enabled (280): 0
libinput Natural Scrolling Enabled Default (281): 0
libinput Send Events Modes Available (259): 1, 0
libinput Send Events Mode Enabled (260): 0, 0
libinput Send Events Mode Enabled Default (261): 0, 0
libinput Left Handed Enabled (282): 0
libinput Left Handed Enabled Default (283): 0
libinput Scroll Methods Available (284): 0, 0, 1
libinput Scroll Method Enabled (285): 0, 0, 0
libinput Scroll Method Enabled Default (286): 0, 0, 1
libinput Button Scrolling Button (287): 2
libinput Button Scrolling Button Default (288): 274
libinput Middle Emulation Enabled (289): 0
libinput Middle Emulation Enabled Default (290): 0
Device Node (262): "/dev/input/event2"
Device Product ID (263): 2, 10
libinput Drag Lock Buttons (291): <no items>
libinput Horizontal Scroll Enabled (264): 1
~ $ cat /sys/class/dmi/id/modalias
I’m also attaching a evemu log of me clicking a few times. As you can see, the last click has no corresponding release.
(If this is observable in the evemu log, does this mean that this is *not* a libinput bug?)
Created attachment 127082 [details]
(In reply to Joachim Breitner from comment #1)
> (If this is observable in the evemu log, does this mean that this is *not* a
> libinput bug?)
Yes, the evemu outputs what available from the kernel, so if the events are not coming through here, it means libinput can't do much (especially for button press/release).
Anyway, this is unfortunately a known bug. It is a firmware issue with the PS/2 firmware of the Synaptics touchpads. You might notice that this happens if your palm rests on the touchpad sensor (with at least 2 touches).
We have a working solution that still needs to be merged. Using RMI4 (custom Synaptics protocol) over SMBus for these laptops solves the bug. Until then, there is not much we can do, besides telling you not to touch the touchpad while pressing the buttons (yeah, this sucks).
Thanks, glad to hear it is known and worked on. Is there an kernel(?) bug report I should monitor?