Calibrated Tocuhscreen "stutteres

Hi,

I am (still) installing Gentoo on my Beaglebone. I am using
xinput_calibrate to calibrate the touchscreen (LCD7).

This works fine as long as I am pointing to a static point
on the screen.

When it comes to moving actions like dragging a window or (more
badly) drawing something, things are becoming awful.
It feels like there would be slack joint between the contact of
the touchscreen and the GPIOs: Every moment X11 is thinking I
had lift the stylus.

As I have learned from this list tslib is no longer in use for
the touchscreen business, since everything is handled via evdev
now.

But are there any filters available as they were with the tslib to
de-jitter, smooth (and like that) the raw data stream coming from the
touchscreen?

How can I fix that?

Thank you very much in advance for any help!
Best regards,
mcc