[xubuntu-users] USB camera being intercepted?

[Peter Flynn]

On 28/11/15 09:56, Petter Adsen wrote:
[...]
> LMGTFY:
> 
> http://gphoto.org/doc/manual/FAQ.html#FAQ-could-not-claim-USB
> See if that helps.

That's extremely interesting, thank you very much for finding it. It
looks like it is describing exactly the situation:

> $ gphoto2 --summary
> 
> *** Error ***
> An error occurred in the io-library ('Could not claim the USB
> device'): Could not claim interface 0 (Device or resource busy). Make
> sure no other program (gvfs-gphoto2-volume-monitor) or kernel module
> (such as sdc2xx, stv680, spca50x) is using the device and you have
> read/write access to the device.
> *** Error (-53: 'Could not claim the USB device') ***

And indeed spca was one of the names I saw in syslog. Now all I need to
do is root it out and destroy it, preferably permanently :-)

The manual goes on:

> You have to make sure that no such kernel module is loaded 

It's been several decades since I had to get dirty with kernels. I have
a look in /etc/modules | modprobe.d/* | modules-load.d/* | depmod.d/*
but there's nothing in them in any way even remotely resembling spca.

However, there are 99 modules in
/lib/modules/4.2.0-18-generic/kernel/drivers/media/usb/gspca/ which are
presumably there for a reason. At the moment it appears all they do is
leap in and prevent applications accessing the USB device. Is there a
way to stop them doing this?

> 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.

I am still not clear what this is. Right now, as far as I can see, there
is no such thing, as the camera doesn't get mounted (*can't* get
mounted, because gspca is preventing it), so no device gets created.

///Peter