Check for usblib
-----------------------------------------------------------------
$ ldconfig -p | grep usb
libusb-1.0.so.0 (libc6) => /lib/libusb-1.0.so.0
libusb-1.0.so.0 (libc6) => /usr/lib/libusb-1.0.so.0
libusb-1.0.so (libc6) => /usr/lib/libusb-1.0.so
libusb-0.1.so.4 (libc6) => /lib/libusb-0.1.so.4
libusb-0.1.so.4 (libc6) => /usr/lib/libusb-0.1.so.4


Check for includes
-----------------------------------------------------------------
$ dpkg -l | grep usb | grep dev
ii  libusb-1.0-0-dev   2:1.0.8-2    userspace USB programming library development files
ii  libusb-dev         2:0.1.12-16  userspace USB programming library development files


Check for usb device
-----------------------------------------------------------------
$ /bin/ls -lAh /dev/bus/usb/004/002
crw-rw-rw- 1 root lp 189, 385 Nov 12 16:15 /dev/bus/usb/004/002


Check for usb permission (not necessary for this test, only for cups)
-----------------------------------------------------------------
$ lsusb
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 002: ID 04a9:310b Canon, Inc. SELPHY CP600
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub


Check for usb build for usb backend --> ok
-----------------------------------------------------------------
$ ./configure --enable-libusb | grep usb
checking for usb_get_string_simple in -lusb... yes
checking usb.h usability... yes
checking usb.h presence... yes
checking for usb.h... yes


Test usb backend --> ok
-----------------------------------------------------------------
$ /usr/lib/cups/backend/usb
DEBUG: list_devices
DEBUG: usb_find_busses=5
DEBUG: usb_find_devices=6
direct usb://Canon/CP600 "Canon CP600" "Canon CP600" "MFG:Canon;CMD:Raster3;MDL:CP600;CLS:PRINTER;DES:Canon CP600;VER:1.00;" ""


Manually create test page
-----------------------------------------------------------------
$ /usr/lib/cups/filter/bannertops 666 root MyTest 1 '' < /usr/share/cups/data/testprint > MyTest.ps
$ /usr/lib/cups/filter/pstopdf 666 root MyTest 1 '' < MyTest.ps > MyTest.pdf
$ /usr/lib/cups/filter/pstopdf 666 root MyTest 1 '' < MyTest.ps > MyTest.pdf
$ /usr/lib/cups/filter/pdftopdf 666 root MyTest 1 '' < MyTest.pdf > MyTest2.pdf
$ /usr/lib/cups/filter/pdftoraster 666 root MyTest 1 '' < MyTest2.pdf > MyTest2.raw
$ export PPD="/etc/cups/ppd/Canon_CP600.ppd"
$ /usr/lib/cups/filter/rastertogutenprint.5.2 666 root MyTest 1 '' < MyTest2.raw  > MyTest2.prn


*** here all check are ok ***


Print
-----------------------------------------------------------------
$ export DEVICE_URI="usb://Canon/CP600"
$ /usr/lib/cups/backend/usb 666 root MyTest 1 '' < MyTest2.prn

DEBUG: print_device
DEBUG: usb_find_busses=5
DEBUG: usb_find_devices=6
STATE: +connecting-to-device
STATE: -connecting-to-device

Nothing is printed and usb backend stop respondig.