[sane-devel] Cannot get hp scanjet 8200 working

[Dave Platt]

On 11/23/2016 09:16 PM, Wolf Drechsel wrote:
> Hello Dave,
> 
> I'm suffering from "avision" trouble as well (you may have read my
> recent posts to this list).
> I'd like to offer my ubuntu 16.10 / hp7400c setup for further testing. I
> sent my log files to this list on Nov 7th, maybe they can be useful.

Hi, Wolf!  I read through your messages and glanced at the logs.  If I
understand correctly, your situation seems to be a "nothing much had
changed, but it no longer works" problem?

The Avision backend hasn't changed in some time (early 2015 was the
last release, I think), which rather points the problem elsewhere.
Unfortunately there are at least four possible culprits:

-  Kernel changes
-  libusb changes
-  Problems in the scanner itself
-  Problems in your PC.

To pin this down I'd suggest a classic "change one part at a time"
elimination test sequence.  What you might try:

-  Test the scanner with the current Ubuntu/SANE distribution on
   another PC.  If it scans OK there, this would rather rule out the
   scanner itself as the problem.

-  Test your PC's USB setup with some non-scanner high-speed transfers.
   One way would be to plug in a USB hard driver or data stick, and then
   "dd if=/dev/sdB bs=$((1024*1024)) of=/dev/null" (substitute the
   correct device identifier) and see if the transfer works successfully
   or if it triggers the USB hang.

   (Based on what you report, I've got a nasty feeling that your
    motherboard host controller may be ill... works OK for low-speed
    transfers, but hangs up somehow during sustained high-speed
    transfers.  The fact that it times out and leaves the bus hung
    is troubling.)

-  Boot up a different Linux distribution on your laptop (e.g. Knoppix)
   and see if you can get the scanner to work reliably.  If so it might
   point to a recent change in your normal kernel and/or libusb as
   being responsible.