[sane-devel] Can't seem to find config files

Igor G Novikov septagramm at gmail.com
Wed Nov 5 17:47:26 UTC 2008

Sun has long set and as my work for today nears its end, i'll try to
write down all questions i have for now.

On Wed, 2008-11-05 at 05:20 -0800, Jack McGill wrote:
> I'm just guessing here, but the mustek_usb2 backend probably doesn't
> need a .conf file because it only supports one scanner at the present
> time. You could try the change the product id in the source code to
> your scanner, in the file that I mentioned previously and rebuild
> sane, and I bet that your scanner will then be recognized by scanimage
> -L.

Well, i did change the source code, fully recompiled and reinstalled
sane, but scanner still ain't detected. I started studying how do sane
backends work and comparing mustek_usb2 backend with mustek_usb. So i
used environment variables to get some debug output from scanimage:

> [root at localhost sane-backends]# export SANE_DEBUG_MUSTEK_USB=4
> [root at localhost sane-backends]# export SANE_DEBUG_MUSTEK_USB2=4
> [root at localhost sane-backends]# scanimage -L
> [sanei_debug] Setting debug level of mustek_usb2 to 4.
> [mustek_usb2] SANE Mustek USB2 backend version 1.0 build 10 from sane-backends 1.0.19
> [mustek_usb2] sane_init: authorize != null
> [mustek_usb2] Asic_Open: no scanner found
> [sanei_debug] Setting debug level of mustek_usb to 4.
> [mustek_usb] SANE Mustek USB backend version 1.0 build 18 from sane-backends 1.0.19
> [mustek_usb] sane_init: reading config file `mustek_usb.conf'
> [mustek_usb] sane_init: config file line 8: trying to attach `usb 0x055f 0x0006'
> [mustek_usb] sane_init: config file line 14: trying to attach `usb 0x055f 0x0001'
> [mustek_usb] sane_init: config file line 17: trying to attach `usb 0x055f 0x0008'
> [mustek_usb] sane_init: config file line 20: trying to attach `usb 0x055f 0x0002'
> [mustek_usb] sane_init: config file line 23: trying to attach `usb 0x055f 0x0873'
> No scanners were identified. If you were expecting something different,
> check that the scanner is plugged in, turned on and detected by the
> sane-find-scanner tool (if appropriate). Please read the documentation
> which came with this software (README, FAQ, manpages).

Also i started studying sources. Looks like mustek_usb2 indeed doesn't
use any configuration file, it's apparent both from debug output and
from sources - function sane_init in mustek_usb2 actually does nothing.
Instead scanner is detected (or not detected) by Asic_Open function.
I'll continue work tomorrow, and for now i have couple of questions:

1. What is Asic? At least some kind of simple definition would make me
alot less confused.
2. Why is that Asic used by mustek_usb2 backend and not, say, mustek_usb
backend? What is it used for in general? And what other backends use it?
3. Is that okay that there's no device detection in mustek_usb2's
sane_init function? Maybe i'm terribly wrong but i think it's because
mustek_usb2 is still incomplete and not because it was originally
intended so.

I want to finally get my device running. And while i'm at it, i'll do my
best to help provide out-of-the-box support for it in sane.

> Also, read this
> http://www.sane-project.org/man/sane-mustek_usb2.5.html
> http://www.meier-geinitz.de/sane/mustek_usb2-backend/
> and
> http://www.meier-geinitz.de/sane/gt68xx-backend/adding.html
> the last reference describes how to add a device to a different
> backend, so the details will be different, but some of the principles
> will be the same.

Thanks for the info. I'm a little confused by the last one though - it's
about GrandTech chipset, while bearpaw is using Service&Quality one,
isn't it?
                                   Igor G Novikov <septagramm at gmail.com>

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