SOLVED Mouse/keyboard freezing after latest upgrade (2023-11-15)

I am running Manjaro Arm on a Raspberry Pi model 4B with a Plasma desktop. After the last upgrade I have experienced freezing of the mouse and keyboard (which means I can’t use PrtScr+REISUB for a safe shutdown, and am forced to remove power from the running PI, hoping that the MicroSD card won’t be fried!). I originally thought it might be caused by a malfunction in a new KVM switch, but on plugging the keyboard, mouse and monitor directly to the Pi, exactly the same problem has arisen. Nor is it a power supply problem, as I use a UPS to avoid surges/drop-outs on the main electricity supply. As I usually point out on these forums, I’m not a systems person, so any help would be gratefully received.

Since no one else has reported similar issues in a long time it is hard to say what is wrong.

File system corruption or sdcard going south. If cpu is overclocked too much it can corrupt large upgrades sometimes. Just because you supposedly have correct power going to your power supply still does not mean the power supply is doing it’s job getting power to the pi4 either. My UPS quit supplying power all together and had to take it out of line.

wayland or Xorg ?

I forgot about your issue. He might switch to the unstable branch and install these packages and see if it helps.

linux-rpi4
linux-rpi4-headers
rpi-overlays
raspberrypi-bootloader
raspberrypi-bootloader-x

echo $XDG_SESSION_TYPE gives the result x11, but this is from a backup made prior to the upgrade.

I have now had time to carry out some fairly exhaustive tests between the ‘faulty’ OS, and the two back-up micro-SD cards, one made before, and the other after the recent system upgrade. It would appear that the culprit was indeed the KVM switch, although since the problem seems to have cured itself, I cannot tell the exact nature of the failure. At least the ‘faulty’ OS card now appears to be working in a stable manner. At the same time, a known problem with this particular switch, when it occasionally loses control of the mouse and keyboard, seems to have gone away!