How to reconfigure phpmyadmin?
run the command:
sudo dpkg-reconfigure phpmyadmin
You need to reconfigure it because lamp and xampp run phpmyadmin in different ports. So, it is probably a port conflict. You can also open server.xml in your lampp and change the port no. which would be different from that of xampp. Then both MySQL (of xampp and lamp as well) will run.
Just run the command:
sudo dpkg-reconfigure phpmyadmin