Occasional ncDeviceOpen problems

idata · ‎09-19-2018

Hi,

I successfully installed the NCSDK in API-only mode on a custom platform (x86-64) and ran the examples. However, from time to time, I get the following errors upon opening the connection with the device:

W: [         0] ncDeviceOpen:533    failed to find device

ncDeviceOpen Failed [-2]: Could not open the device.

and

E: [         0] dispatcherEventSend:730    Write failed -4

Hello NCS! Device opened normally.
Goodbye NCS!  Device Closed normally.
NCS device working.

Log of a successful run (dmesg):

[Sep19 07:29] usb 3-1: USB disconnect, device number 2
[  +0.248874] usb 4-1: new SuperSpeed USB device number 2 using xhci_hcd
[  +0.020071] usb 4-1: New USB device found, idVendor=03e7, idProduct=f63b
[  +0.006850] usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  +0.008001] usb 4-1: Product: VSC Loopback Device
[  +0.005103] usb 4-1: Manufacturer: Intel Corporation
[  +0.005347] usb 4-1: SerialNumber: 1FF861D5542010
[  +1.242801] usb 3-1: new high-speed USB device number 3 using xhci_hcd
[  +0.134026] usb 3-1: New USB device found, idVendor=03e7, idProduct=2150
[  +0.006821] usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  +0.007819] usb 3-1: Product: Movidius MA2X5X
[  +0.004701] usb 3-1: Manufacturer: Movidius Ltd.
[  +0.004939] usb 3-1: SerialNumber: 03e72150
[  +0.351915] xhci_hcd 0000:02:00.0: Cannot set link state.
[  +0.007609] usb usb4-port1: cannot disable (err = -32)
[  +0.005258] usb 4-1: USB disconnect, device number 2

Log of a unsuccessful run:

[  +0.250331] usb 4-1: new SuperSpeed USB device number 33 using xhci_hcd
[  +0.019707] usb 4-1: New USB device found, idVendor=03e7, idProduct=f63b
[  +0.006873] usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  +0.007885] usb 4-1: Product: VSC Loopback Device
[  +0.005087] usb 4-1: Manufacturer: Intel Corporation
[  +0.005335] usb 4-1: SerialNumber: 1FF861D5542010

It seems like when switching from USB2.0 to USB3.0 it gets stuck.

This happens both using the hello_ncs_cpp example and the python examples from the ncappzoo.

After a few tries the examples start, other times (more commonly) the examples starts right away.

Notes:

This problem emerged using both the Movidius Neural Compute Stick and the UP AI Core.

The USB connection is provided by an internal USB hub.

What could be the possible cause of this behaviour?

Edit: Added dmesg logs.

idata · ‎09-26-2018

For future reference: I uninstalled the ncsdk 2.05.00.02 and installed the 1.12.00.01. Now everything works correctly.