Re: mustek problems in lineart mode

becka@sunserver1.rz.uni-duesseldorf.de
Fri, 12 Sep 1997 19:16:15 +0200 (MET DST)

Hi all !

I have received 4 private replies to that EMail, so it seems to be a common
problem we should try to track down.

> >> This doesn't always work. The scanner simply stops in the middle of the page
> >> and scanimage seems to hang. Using xscanimage the problem is the same. Other
> >> modes than lineart work fine.

> >I see similar problems here. It doesn't seem to depend on the mode (actually
> >I cannot reproduce exact conditions under which it fails), but from time to
> >time my MFS 12000 SP will hang and the SCSI system will be taken down with
> >it. If you reboot the system without powering off the scanner in the meantime,
> >the system will hang again when the SCSI driver gets loaded.

> Well, that's exactly what happens here. The only difference seems to be that for
> me it only happens in Lineart mode.

>From the information I have received, it looks like it doesn't depend much on
the SCSI adaptor/subsystem. I have had reports from NCR53c400 and 53c810
plus some more which didn't tell me the adaptor. Can anyone confirm, that it
is not an NCR related problem ?

The first idea I had was that maybe something (the scanner) is hogging the
SCSI bus for too long and resetting fails. However the hang seems to be
real hard, as my /var partition resides on an IDE HD and should thus be
able to log, even if the SCSI-Bus hangs. But what I get is :

Aug 17 17:15:15 gate kernel: Detected scsi generic sga at scsi0, channel 0, id 6, lun 0
Aug 17 17:17:50 gate kernel: Kernel logging (proc) started.

I.e. no error messages between opening the device and the crash.

We should investigate further, as the effect seems to have been introduced
by SANE. I have not seen such problems with mscan and muscan.

Several possibilities for the cause come to my mind :

- I will try to use the strip-height option to see, if disconnect times are
the problem.

- Moreover it would be nice, if we could check if the problem is reproducible
for given parameter sets. So if you see such a hang, write down the command
line (for scanimage) and retry. If it reproducibly hangs, please post the
parameters, so we can cross-check and maybe find a rounding-error or
something the like in the code.

If you have other supects, please add them to the list, so we can all try to
test them out. Reproducability across different systems would be a big win,
as it would tell us that it is most likely not a timing problem.

CU,Andy

-- 
Andreas Beck              |  Email :  <becka@sunserver1.rz.uni-duesseldorf.de>
========  GGI - The Right Thing To Do : http://synergy.foo.net/~ggi/  ========

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