SUMMARY It seems that after a long time of this bug I cannot find a concrete way to reproduce it, so reporting it as is. While working in a Plasma session, sometimes I notice that tap-to-click no longer works for my touchpad (despite being enabled in System Settings, of course). This is a permanent state in a sense because once it starts you can only temporarily work around it by doing an activity switch (pressing Meta+Tab twice). I suspect that this bug itself gets triggered after nth Plasma activity switch, but I am not certain. SOFTWARE/OS VERSIONS Operating System: openSUSE Leap 15.2 KDE Plasma Version: 5.20.4 KDE Frameworks Version: 5.77.0 Qt Version: 5.15.2 Kernel Version: 5.10.2-1.g572ce1d-default OS Type: 64-bit ADDITIONAL INFORMATION The touchpad input driver in use is Synaptics.
It is possible that somehow Kate is involved in this: I often (always?) find myself using Kate when this happens.
I wonder if this has anything to do with Bug 414559. Can you reproduce the issue immediately after executing `sudo udevadm trigger -s input`?
Hmm, no...
OK, than I guess it's not that!
When tap-to-click stops working, can you run sudo libinput debug-events from terminal and tap a few times, do you see POINTER_BUTTON events?
No, only POINTER_MOTION, regardless of whether tap-to-click works
I also have this issue, often while working in Blender. For me the issue can be resolved by going back into the touchpad settings, deselecting the tap-to-click option, reselecting it and then hitting apply. My computer utilizes a detachable keyboard with touchpad which also supports hardware left/right clicking by clicking on the lower left/right corners of the trackpad respectively so I don't fully lose mouse click functionality when tap-to-click stops working.
Update on the Kate involvement: it's not Kate, but rather Home/End keys. On my laptop, they are accessible as Fn+(left/right keys). Sometimes when I press Home/End, the text cursor starts moving towards the start/end of the line letter-by-letter instead of jumping immediately. This triggers the tap-to-click bug, and sometimes also scrolling with two fingers stops working. All this mess somehow disappears when I press Meta-Tab twice, switching from an activity and back... This happens randomly, but regularly.
Sounds like a bug in your keyboard hardware. I've experienced a very similar thing with an HP laptop. Sometimes the arrow keys would get virtually stuck in the pressed position, endlessly sending key events until physically pressed again. Sounds like that's compounded by your Fn key not sending its pressed signal. I have no evidence whatsoever of any of this, but it matches some experiences I've had in the past with crappy PC keyboards that didn't have n-key rollover.
I'm pretty sure it's a software issue, because it influences the touchpad and because the unrelated act of switching Plasma activities can be used as a workaround. There are variations of how this bug occurs when after getting triggered once it starts repeating, and only one tap works as expected, so I have to switch activities after every tap for clicking to work, without any interaction with the Fn key. As established earlier in this thread, the events sent by the touchpad are the same, so it's not some laptop-wide hardware breakage.
This also seems to somehow cause Kickoff to stop responding to the Meta key
I haven't seen this in quite a while, closing