I purchased another redfury and it gave me exactly the same problem. The issue seems to be rooted in the raspberry pi's usb load/usb power management. A powered hub doesent help. From what i can tell there is no solution, but i was able to get one device running at a time - further suggesting a load issue. Giving up until the elephant leaves the room.
Having a really strange issue with cgminer and a 2.2gh/s bitfury redfury running on raspbian on my newest version pi.
Everything Is setup as it should be, system updated dependancies installed, cgminer built with proper config for bitfury ASIC.
I know it was set up ok because it hashed for a week with no problems.
The problem seemed to start when i reset the pi, i now get no hashes in cgminer, it starts long polling and detects my device as BF 0 , but it has 0 hashrate, will not mine at all.
It works fine on my other cgminer pc which runs windows. So im really confused.... does anyone have any suggestions? :3