"Could not claim interface on camera: -6" when trying to connect usb camera (Kinect)

Question

I have installed the freenect library from openkinect.org. With that library there is a demo application which you can run from the terminal to test out the Kinect. However when I run this command I get the following output:

richard@behemoth:~$ sudo freenect-glview 
Kinect camera test
Number of devices found: 1
Could not claim interface on camera: -6
Could not open device

This particular error is thrown by the library libusb by the function libusb_claim_interface and the error -6 corresponds to the LIBUSB_ERROR_BUSY. So my guess is that it has something to do with mounting the usb, rather than specifically the freenect library or the Kinect itself.

So my question is how can I find out what resource is using this interface and how can I free it so that I can access it?

Edit:

What I have tried so far (just to be sure):

• Rebooted
• Plugged-out, plugged-in
• Tried different usb ports
• Restarted udev

---

Additional information that might be useful:

/etc/fstab:

# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    nodev,noexec,nosuid 0       0
# / was on /dev/sda1 during installation
UUID=1c73f217-ac8d-451b-8390-7a680628a856 /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda5 during installation
UUID=bb49bd29-07ec-45a0-bbab-46fb8362b06b none            swap    sw              0       0

sudo uname -r:

Linux behemoth 3.0.0-14-generic-pae #23-Ubuntu SMP Mon Nov 21 22:07:10 UTC 2011 i686 i686 i386 GNU/Linux

cat /etc/lsb-release

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=11.10
DISTRIB_CODENAME=oneiric
DISTRIB_DESCRIPTION="Ubuntu 11.10"

Answer 1

I don't have your environment and cannot test, but this excerpt from the gphoto FAQ seems to say that this might be a matter of permissions, rather than some program monopolizing the interface.

The following quote contains a link to the Setting up permissions for USB ports chapter that you could check.

Why do I get the error message "Could not claim the USB device"?

You have to make sure that no such kernel module is loaded and that you have set up the permissions on your USB device correctly, such that you have (non-root) write access to the camera device. How to set this up, is described at Section 4.3, Setting up permissions for USB ports.

This can also happen with cameras that works as USB Mass Storage devices. A notable example is if you have an Olympus Camera that gets auto-detected as an Olympus C-2040Z. In this case, you can try, if you run Linux, to remove the usb-storage kernel module and attempt to use libgphoto2 with it. But, unless you want to control the camera (not all the model supports it), it is not a recommended solution. Keeps using USB Mass Storage. Some of these Olympus supports to be switched to "PC Control" mode in order to be remote controlled with an external program like one using libgphoto2.

Answer 2

It sounds very much like that another driver is holding or using your device. Run:

lsusb

And try to find the line with kinetic

Bus 002 Device 004: ID 046d:0850 Logitech, Inc. QuickCam Web

Copy'n'paste the string after ID (like 046d:0850) to google and see if you happen to come across matching linux kernel module.

If your lucky then add it to the blacklisted modules. Create your own file to /etc/modprobe.d/blacklist-kinetic.conf

blacklist MODULENAME

run depmod -a reboot and try again

Just be careful not to blacklist any modules that you actually need.

Answer 3

This was a bit confusing, but I finally figured it out.

The newer Linux kernels come with a driver to use the Kinect as a web cam, and it appears to be grabbing the Kinect cam first, which results in the error message when you try to run freenect-glview: "Could not claim interface on camera: -6".

Do an lsmod and pipe that to a grep on the gspca string so you only see the gspca listings:

 lsmod | grep gspca
 gspca_kinect   12792     0
 gspca_main     27610     1     gspca_kinect
 videodev       85626     1     gspca_main

 modprobe -r gspca_kinect
 modprobe -r gspca_main

Then the freenect-glview should work.

Answer 4

Newer linux kernels have the ms gspca drivers installed and will not detach. They only give you the rgb camera and ir without depth, so kill them!

lsmod

Should list them all. Find the two gspca modules. kinect and main, I believe.

then modprobe -r gspca_kinect

Then kill the other, and try freenect-glview again. Life is good!