After a hardware upgrade, an update from QT4 to QT5 was necessary. The hardware contains a small keyboard and under QT4 I was able to activate automatic repetition with the following environment variable:
QWS_KEYBOARD='LinuxInput:/dev/input/event0:repeat-delay=500:repeat-rate=200'
On QT5 I tried the same thing with
QT_QPA_EVDEV_KEYBOARD_PARAMETERS='/dev/input/event0:repeat-delay=500:repeat-rate=200'
The keyboard works, but the automatic repetition of keys does not work. Is there something I have overlooked?
After all, the problem is now solved. If anyone stumbles across this thread, this was the solution in this case:
The hardware upgrade also required a Linux kernel upgrade. And in the device tree the 'autorepeat' attribute for the gpio keys driver was missing.