The trick is simple, but not obvious:


echo "disallow method ppdev" > /etc/ieee1284.conf


I have tried to use the Lattice ispVM under Ubuntu 11.04, with the Lattice USB download cable, but I have to run it as root, even after adding the udev rules mentioned in the FAQ.

After some strace analyzing I have figured out that it is trying to open the /dev/bus/usb/{roothub}/{devide} nodes. Since then the download cable's node was read only it failed.

I have written the following udev rule to the /etc/udev/rules.d/51-lattice.rules file inspired by my AVR doper's rule:


SUBSYSTEM=="usb", ACTION=="add", ATTR{idVendor}=="1134", ATTR{idProduct}=="8001", MODE="0666"