How to deactivate kernel output on ttyS2?

[ellerbach]

Hi,
I'd like to fully deactivate the console output on ttyS2 as I'd like to use it. How is it possible to do it?
I'm quite new on Linux boards, I4ve try to search for that, understand that there are things to do with the u-boot or equivalent but really didn't find a simple how to to make it possible.
I'm using a Debian version on the RockPro64. The one recommended.
Thanks a lot

[rhex]

Use systemctl [stop|start|enable|disable]

1. Check for getty
$ ps aux | grep getty
root       829  0.0  0.0   3980  1992 ttyS2    Ss+  02:21   0:00 /sbin/agetty -o -p -- \u --keep-baud 115200,38400,9600 ttyS2 vt220

2. Stop getty on ttyS2.
$ sudo systemctl stop serial-getty@ttyS2.service

Repeating the ps command will show that getty is gone, but it will return after reboot.  To persist you can:

3. Disable getty on ttyS2:
$ sudo systemctl disable serial-getty@ttyS2.service