I NPUTransfer: Starting NPU Transfer Client, Transfer version 2.1.0 (b5861e7@...

我使用的是RK3399ProX这块开发板，这边使用  pip3 install --user -U tensorflow==2.0.0装了TensorFlow，pip3 install --user -U rknn_toolkit-1.6.0-cp37-cp37m-linux_aarch64.whl装了RKNN，然后读模型每次都报错如下：
toybrick@debian10:~/dome$ python3 rknn_camera_tiny.py
-->loading model
I NPUTransfer: Starting NPU Transfer Client, Transfer version 2.1.0 (b5861e7@2020-11-23T11:50:51)
[ 2161.355492] usb 4-1: USB disconnect, device number 4
E RKNNAPI: rknn_init,  recv(MsgLoadAck) fail, -9(ERROR_PIPE) != 368!
E Catch exception when init runtime!
E Traceback (most recent call last):
E   File "rknn/api/rknn_base.py", line 844, in rknn.api.rknn_base.RKNNBase.init_runtime
E   File "rknn/api/rknn_runtime.py", line 340, in rknn.api.rknn_runtime.RKNNRuntime.build_graph
E Exception: RKNN init failed. error code: RKNN_ERR_DEVICE_UNAVAILABLE
Init runtime environment failed
[ 2162.717987] usb 4-1: new SuperSpeed USB device number 5 using xhci-hcd
[ 2162.730098] usb 4-1: New USB device found, idVendor=2207, idProduct=0019
[ 2162.730791] usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 2162.731445] usb 4-1: Product: rk3xxx
[ 2162.731849] usb 4-1: Manufacturer: rockchip
[ 2162.732247] usb 4-1: SerialNumber: f298fc3b73f1db90
请问是什么原因，该怎么解决？