/** Initiate a interrupt transfer read.
*
* Read up to size bytes from the interrupt endpoint from the device to
* buffer. After the read, size contains the number of bytes actually read.
*
* @param dn device number
* @param buffer buffer to store read data in
* @param size size of the data
*
* @return
* - SANE_STATUS_GOOD - on succes
* - SANE_STATUS_EOF - if zero bytes have been read
* - SANE_STATUS_IO_ERROR - if an error occured during the read
* - SANE_STATUS_INVAL - on every other error
*
*/
usb_find_busses only once. Make sure that already opened devices aren't opened
again. Exit libusb scan loop if one device is found. Make error values more
expressive. Check for missing config descriptors before using them to avoid
segfaults.
Henning Meier-Geinitz <henning@meier-geinitz.de>