Comment 69 for bug 83587

Description of problem: Preview fails in xsane with a ScanJet 5370C using the
avision sane backend.

On the first attempt, the preview scan is successful. On the second, and all
further, attempts the scan head moves back and forth a small amount (initial
alignment?), then makes the noise (possibly motor strain?) or trying to make the
preview scan - but the scan head doesn't move.

All further attempts fail until _all_ the following have been performed:
1) unplug the scanner from mains and USB
2) modprobe out, then modprobe in ehci_usb (I can't try uhci_usb due to bug 200122)
3) plug the scanner back in
4) run a preview scan in VueScan

Now, 4) seems odd - but if I don't do this then xsane hangs on startup with
device I/O errors. This behavior bears a striking similarity to the problems I
had in bug 205092 comment 1; indeed after the first failed preview scan, if I
unplug the scanners USB cable then plug it back in (without bus or scanner
reset) I get the error:

Sep 12 00:13:10 localhost kernel: usb 1-1.3: new full speed USB device using
ehci_hcd and address 8
Sep 12 00:13:13 localhost kernel: usb 1-1.3: device descriptor read/64, error -110

This is also the "another (different again) USB" error of bug 205092 comment 1;
this bug is now solved, but the behavior seems similar. I don't know what's
going on in the avision backend, but it seems almost as though it puts the
scanner into some kind of undefined state.

Version-Release number of selected component (if applicable):
sane-backends-1.0.18-2.fc5

How reproducible: Once triggered, always.