[sane-devel] FreeBSD and Microtek Scanmaker II

Nakal nakal@web.de
Sun, 15 Jun 2003 01:27:59 +0200

On Thursday 12 June 2003 12:10, abel deuring wrote:

> A long shot: IIRC, these Microtek scanners may freeze, if you access
> them with another LUN than 0 -- but they show up with all LUN values
> from 0 to 7. So, if any backend tries to access the scanner with a
> non-zero LUN, you'll have an unaccessible scanner. I don't know any
> details, but *if* a SCSI command to a non-zero LUN confuses the scanner
> in a way that the entire SCSI bus is blocked, worse errors may occur,
> e.g., the disk with the root partition may be unaccessible. So it's best
> to connect these cheap scanners to their own SCSI bus.

OK. I did that. I disconnected all devices except the scanner. I get still 
same effect.

> And you should tell FreeBSD not to look for all LUNs of the scanner
> while it tries to detect devices on the SCSI bus.

Yupp, I did that too, still same. It still gets timeout. I found out that I 
can scan gray pictures, because it's only one pass. It works perfectly! But 
as soon as the scanner tries another pass (e.g. color mode) then it does not 
react (like it forgot the last SCSI command it got). It does not freeze. The 
scanner is simply idle.

I think, sane should repeat the SCSI-command until it succeeds and gets ACK 
and not just wait for ACK, because there won't come any as long as the 
scanner moves back the carriage. I can directly start another scan after 
pressing control+C. There is no problem, but it will always get timeout while 
initializing the scan for the second pass in 3-pass mode.

I remember that earlier (1 or 2 years ago) when I used Linux, sane worked with 
my microtek without problems.