[sane-devel] FreeBSD and Microtek Scanmaker II

abel deuring a.deuring@satzbau-gmbh.de
Thu, 19 Jun 2003 21:59:10 +0200

Nakal wrote:

> I really don't understand SCSI much. FreeBSD gives me still "unexpected 
> disconnect" with my scanner, after I switched off "disconnection" in my 
> controller's BIOS.

Could the FreeBSD driver ignore the BIOS settings? I assume that you can 
pass a parameter like "don't disconnect" to the driver.

> Yes. It is a quite "cheap" scanner and came with a separate ISA SCSI-1 
> controller. Now I'm using one with a Symantec chipset (Tekram 
> DC390/UW). The scanner is attached to external UW bus. I wonder if it 
> is really correct to connect it like this, but IT WORKED earlier (1 or 
> 2 years ago?) on Debian, so it should not be a problem.

Well, a fast SCSI adapter may have problems with a slow device, but I 
don't believe that this is the case hre. After all, the scanner finishes 
one of the three passes, and that shows that several SCSI commands were 

>>    it is unclear which commands can be sent during that delay, if
>>that delay can be polled (i.e. ask the scanner if it is ready) or if
>>it must be guessed, etc, etc.
> There is a possibility to compile the FreeBSD kernel with CAM debugging. 
> This produces LOTS of information (see: man camcontrol(8)). With just a 
> bit luck, there might be some useful information about the scanner's 
> behavior.

That could be interesting -- but currently I think we can stay with the 
Sane debug messages.

> I don't know how many people are using old Microtek scanners. If it is 
> too much trouble, simply forget it.
 From my POV, we should continue ;) I think you had simply the bad luck 
of being the first one to discover a bug in sanei_scsi.c (and perhaps 
another one in the Microtek backend) -- but these bugs could bite more 
people, if we don't fix them... And while I would really prefer it to 
leave the patches for sanei_scsi.c to somebody who has FreeBSD 
installed, I'll try to do it myself, if nobody shouts "I'm 
volunteering". But expect some extra work fixing typos in my patches ;)


PS: Considering the log output from running the Scanmaker II under 
Linux, it its perhaps worth, if you try my simple patch to sanei_scsi.c 
I am not sure, but both the backend and the scnner seem to be able to 
deal with a few failing commands. And the patch passes slightly better 
erro informations to the backend.