Canoscan 5600F grey scan does not work
Canoscan 5600F colour scan works fine. However, Gray scan hangs in the genesys backend.
Traced the issue to the wait_until_buffer_non_empty() function. It never returns because calls to sanei_genesys_is_buffer_empty() to determine if scan data is available never returns true. The scanner head does move all the way to the end of the platen with the light illuminated. So it appears to be going through the motions, but there is no indication that data is forthcoming.
My theory is that the setup for the scanner is correct for the motor but incorrect for the frontend so that no data is actually captured during the head sweep.