[sane-devel] debugging the Canon i-SENSYS MF211

[Morten Juul Møller]

Dear Sane-developers!

I'm currently in possession of a Canon i-SENSYS MF211.
It's a 3-in-1 machine that can print, copy and scan. 
The device supports both Wifi, Ethernet and USB. I'm currently using 
USB.


I'm trying to get it to work under Linux (Mageia 5, i586).
Printing (and copying) works fine, but not scanning. 
On the Sane "supported devices" page it is marked as "untested, 
testers needed!".
It is supposed to use the Pixma-backend.

I've tried both Sane backend version 1.0.25 and a more current 
snapshot from 20th of May 2016 (both compiled from source with no 
alterations by me).
Both versions generates the same errors, although the scanner finishes 
much faster when using the snapshot.

The scanner is recognized by sane-find-scanner, and when I try to use 
scanimage I do actually get an image, but only the first lines of the 
picture.

When running the program with SANE_DEBUG_PIXMA=21 I notice three error 
messages:

"WARNING: Unexpected result header", 

"ERROR: ETIMEDOUT" 

and finally

" WARNING:image size mismatches
[pixma]     1683840 expected (877 lines) but 30720 received (16 lines)
[pixma] pixma_read_image(): completed (underrun detected)"

The error messages are very consistent, however when scanning in 
grayscale-mode Sane only receives 8 lines:
"561280 expected (877 lines) but 5120 received (8 lines)"

I would like to help debug the problem, but I'm not familiar with the 
pixma-protocol, so I need some ideas. 

Should I post the complete dump of debug-messages as inline text to 
the mailinglist (default scanning-mode produces a 132 KB textfile of 
debug messages) ?

Regards
Morten Juul Møller