Still working on the microtek2 backend stuff for libusb... It seems that the odd issues I'm encountering will go away if I don't ever close the USB device. If I leave it open for the duration of the backend lifetime, scanimage -L will properly identify it. If I open and close it for each operation, I get timeouts trying to read responses, and if I increase the response size the scanner will send back a larger packet which seems to show that I miss the first block of data (32-bytes for this scanner).
Is this a problem anywhere else with the libusb stuff? Is there harm in leaving the scanner open until sane_exit ? At least for now doing this allows scanimage -L to find the scanner. That is good. However, another glitch is cropping up when I try to send the system_status block back to the scanner... The USB log shows the transmission is without error, but after that point I get no more response from the scanner to the remaining commands. The odd thing is, I've not changed anything about the logic of what is being sent to the scanner, just sending it via libusb instead of writing to the fd of the linux kernel scanner driver. Oh well. :-)
