i tried this again, but didnt work. looks like the config.txt changes dont have any affect in touch panel display,
its working when i run this command through ssh terminal.
sudo udevadm control --reload-rules
sudo udevadm trigger
after running this in command prompt, i have to go to zynthian → admin → touch panel calibration, and then need to do the calibration. but the problem is, i have to do this everytime i restart the zynthian.
thanks and regards