Re: what is sitting on USB device?

[Mark Copper <mcopper@straitcity.com>]

On Tue, Oct 23, 2018 at 11:28 AM Curt <curty@free.fr> wrote:
>
> On 2018-10-23, Mark Copper <mcopper@straitcity.com> wrote:
> > Trying to connect to a device, I get this error message:
> >
> > *** 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') ***
> >
> > On general Linux principles, how does one go about what is keeping the
> > device busy? How does one distinguish between "busy" and a permissions
> > problem?
>
> On the internets I glanced at a forum thread where someone opined that
> 'gvfs-gphoto2-volume-monitor' might get in the way of camera-like
> thingamajiggers:
>
>  ps aux | grep gphoto
>
> to see whether this theory is viable or not (and if it is, you know, close or stop
> or kill that gvfs puppy maybe).

yes, there is a gnome environment variable that can stifle the gvfs
monitors and I have done that. Nor do I see any trace of the modules
mentioned in the error message.

so I thought I'd try to go back to first principles and ask how one
might discover what is already using the device.