[sane-devel] Problem with CanoScan N656U & Mac OS X 10.3.3

Mattias Ellert mattias.ellert@tsl.uu.se
Tue, 06 Apr 2004 17:07:04 +0200

Gerhard Jaeger wrote:
> Hi Mattias,
> how is the current state of the OSX support within the Plustek backend.
> Have you any patches? I'm currently very short of time, but I'd like to do
> what's necessary to not forgot your work.
> I've not forgotten the pending sanei_thread stuff!

At the moment I have 4 open bug reports in the bug reporter.

300602, 300617, 300618, 300620

The first one is what I think you mean when you say "the pending 
sanei_thread stuff". I'm not sure if it is possible to fix this in the 
short term in a good way. The patch attached to the bug report is really 
just a temporary workaround (and was applied when I built the latest 
binary package).

A slightly better proposal for a fix is suggested in a comment I made to 
the original bug report, but that one requires some coordination between 
the backend maintainers to implement. And there possibly are other ways 
to do it as well which might be better.

This problem probably does not affect the plustek backend to a large 
extent, since the plustek backend only calls sanei_thread_kill (which is 
the call that is broken due to this problem in those backends that - 
like the plustek backend - block SIGUSR2) if the SIGUSR1 signal sent by 
the backend fails to kill the reader thread within 10 s. Some other 
backends rely more on this call to work.

The second and third ones are minor fixes to sanei_thread that have not 
been seen to cause problems, but I noticed them when I was trying to 
figure out what was going on in the plustek backend.

The fourth one is the specific patch to the plustek backend I just 
submitted. Without this one the plustek backend hangs on the read call 
in sane_read at the end of a scan.

The only patch that I have that I have not yet submitted to the bug 
reporter is totally unrelated to the plustek backend. It is a possible 
but yet untested fix to a timeout problem in the sm3600 backend. I'm 
waiting to hear from the reporter of the problem if the patch works 
before submitting it, but if someone else want to try it I can send it 
to that someone if they get in touch with me.



mattias.ellert@tsl.uu.se                           tel: +46 18 471 32 58
http://www.tsl.uu.se/~ellert/                      fax: +46 18 471 35 13