xinput-calibrator XChangeDeviceProperty calls ignored

[Marco Cavallini]

Hi,
I'm testing and debugging xinput-calibrator and looks like
CalibratorEvdev::do_set_prop - XChangeDeviceProperty calls are ignored
by Xorg.

I wonder who is responsible of touchscreen coords adjustment.
Does exist a documentation about the flow beginning from touching the
screen up to X cursor moving on the screen?
Which are the libraries involved into this operation?

TIA

/marco