Hi!
I have same problem on Debian 10 and board N10a
./rockx_head_detection test.jpg
E NPUTransfer: Cannot connect to proxy: Connection refused
E RKNNAPI: rknn_init, driver open fail! ret = -4(ERROR_NO_DEVICE)!
1600266171553 rockx load_model(74): rknn_init fail! ret=-3
1600266171559 rockx init(72): init module(9) error -1
Segmentation fault
root@rockpin10a:/home/rock# npu_powerctrl -i
init gpio: 4
Error writing to /sys/class/gpio/export value=4: Device or resource busy
gpio init
root@rockpin10a:/home/rock#
Downgrade to rockchip-npu 4.0 not help
root@rockpin10a:/home/rock# lsusb
Bus 008 Device 002: ID 2207:1808 Fuzhou Rockchip Electronics Company