[sane-devel] Broken ADF-support in pixma-backend: devs needed

[Jörn-Ingo Weigert]

Hello list!

Since the changes between 1.0.25 to recent 1.0.27 version of Sane it turns
out, that the ADF support for most (if not all) Canon pixma models like
Maxify AIO printers are broken.

Rolf Bensch, maintainer for the pixma-backend, told me that he is too much
involved in other projects, so there is less time to get involved into the
ADF issue and also, he have less experience in this topic.

So I'm looking for an developer here who can help on fixing the ADF.

As it turns out, the use of ADF end in a (silent) segfault when using a
graphic frontend. In result, Simple scan / XSane try to scan but after a
short time the scan progress get cancelled. The ADF does not react in any
way, neither try to move the document nor moving the scan line to the ADF
scan position.

Since this is a long standing behaviour, it would be great, when someone
take a heart and want to dive in to fix it.

Kind regards,

Jörn-Ingo Weigert

[Jörn-Ingo Weigert]

Thank Ralph, if you can dig into this, that will be really great. I agree,
tour assumptions regarding same hardware base do make sense. I hope, Canon
engineers had the same idea. ;)

Just give me a hint, if you like to have some debug output to compare from
the model I use when you have time.

Kind regards,

Jörn-Ingo Weigert

Hi,
I have also had problems with my Canon MF4770N and Rolf has been kind
enough to assist in the past although it has become increasingly apparent
that he is really busy with other things.
It still doesn't work and it is something that I would like to rectify.
I do have the skills to get to the bottom of it, but I also don't have
much time to devote to it but it is on my TODO list sort out.
For my scanner, some of the setting combinations don't work very well or
sometimes put the machine in a hardware failure state resulting in my
having to power cycle it, most likely the result of a timing issue or an
illegal combination of options. So there is clearly much work to be done. :(
Having gained experience with that I might be able to help with other
models. I have a feeling that once one is fixed, a number of other models
will be pretty much the same. Companies like Canon tend to output lots of
models that are pretty much the same inside and it wouldn't surprise me to
discover that solving the problem with one would solve the problem with
many.
When ADF scanning fails on my multi function then I suspect that sane and
the scanner are out-of-sync, a situation which is difficult to recover from
without some kind of reset of the scanner itself. Sane thinks that the
scanner has reported an error and aborts whereas the scanner is waiting for
instructions to continue the scan from sane.
I will try to put some time aside to deal with this over the next few days
but I cannot give any guarantees however.
Cheers,
Ralph Little