Intempestive Touchscreen Events on Linux ARM

jean_b

I experience intempestive / undesired touch events when running a Qt Quick application. Would you know what could be the cause?

Test configuration:

Linux 5.10
Qt 5.12.5
Capacitive touchscreen with SITRONIX controller

Step 1: boot and monitoring the interrupt pin from the touchscreen for 2hours: no interruption
Step 2: launching evtest for 1hour: no interruption
Step 3: launching a Qt application with QT_LOGGING_RULES set:
-> the SITRONIX device is detected for the evdevmouse and evdevtouch objects.
-> approximately 1 interruption / minute while nothing touches the screen
Step 4: stop (Ctrl-C) the Qt application: intempestive interruptions keep going

Same results with:

tslib instead of evdev
mtdev enabled
the evdevmouse disabled

jean_b

The issue came from the touchscreen controller calibration