jupiter linux # lsusb
Bus 002 Device 017: ID 04a9:220d Canon, Inc. CanoScan N670U/N676U/LiDE 20
If you keep the device awake with
while true; do sleep 1; cat /dev/bus/usb/002/017; done > /dev/null
(replace 002 and 017 with your bus and device id from lsusb)
you can do a preview and a full scan in e.g. kooka, but usually only one time. When it stops working, the scanning application has to be restarted. Looks like the backend or libusb cannot keep the device awake long enough.
Same problem here with this hardware:
jupiter linux # lsusb
Bus 002 Device 017: ID 04a9:220d Canon, Inc. CanoScan N670U/N676U/LiDE 20
If you keep the device awake with
while true; do sleep 1; cat /dev/bus/ usb/002/ 017; done > /dev/null
(replace 002 and 017 with your bus and device id from lsusb)
you can do a preview and a full scan in e.g. kooka, but usually only one time. When it stops working, the scanning application has to be restarted. Looks like the backend or libusb cannot keep the device awake long enough.
Ideas for this found here: https:/ /bugs.launchpad .net/ubuntu/ +source/ sane-backends/ +bug/85488