[sane-devel] Avision: Hardware cancel and software cancel are both buggy with FB2280E

[Paul Wolneykien]

  Hi!

  With the Avision FB2280E scanner there are two options to cancel a
running scan: by calling sane_cancel() (clicking "Cancel" in XSane)
and by pressing the "Cancel" hardware button on the scanner. Both
options seem to be buggy.

  Calling sane_cancel() doesn't abort the scan on the hardware level:
the scanning head moves on to the end of the area. Moreover, the next
scan attempt results in reading cached data without the actual scan!
I'm not sure where it is cached: in the scanner or in the backend, but
it's obviously that sane_cancel() doesn't perform some kind of clean or
reset, so the next scan is done as a continuation or a restart of the
previous scan.

  Is that a known behaviour with Avision? And, possibly, with other
scanners/backends?

  Next. Pressing the hardware "Cancel" for the first time, aborts the
current scan (the light is turned off, the scanner's head returns to
the start [though, slowly!]). However, that makes further scanning 
impossible: a long delay, then a permanent I/O error is reported.
Libusb reports "err: 11 Resource temporarily unavailable". Restarting
XSane without poweroff the scanner (!) fixes the problem.

  Is that a known behaviour with Avision?