On Tuesday, 5. October 2010 15:51:33 Thomas Klose wrote:
> Am Dienstag, den 05.10.2010, 15:20 +0200 schrieb Thomas Jarosch:
> > On Tuesday, 5. October 2010 14:35:25 Thomas Klose wrote:
> > > If I open a ftdi device in an instance of our application it seems
> > > not to be claimed for exclusive access. A second instance of the
> > > application can "steal" the device later.
> > >
> > > I found in the sources of libftdi that the libusb function
> > > usb_claim_interface() is called correctly by ftdi_usb_open_dev(). It
> > > was my understanding that usb_claim_interface() marks the device to
> > > be "in use" and a second call would result in an appropriate error.
> > Well, the function does what it's named after: Claim the device, no
> > matter who is currently using it: Kernel driver or another libftdi
> > instance.
> Sorry, I do not understand. Does this mean, when a device is
> successfully claimed, it always can be used by other instances?
> If this is the case, is there a possibility to signal the other instance
> that the device is already in use, e.g. get usb_claim_interface() to
> return -EBUSY?
Sorry, I might be wrong on this one, just rechecked with the man page.
Have you tried to trace it with a debugger what is really going on?
libftdi - see http://www.intra2net.com/en/developer/libftdi for details.
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