[sane-devel] Weird snapscan firmware behaviour (bug?)

[Werner]

Hi!

First of all, I am not a hardware expert, and my English is not that 
good :-) I have found some weird bahaviour, and it might be a bug, but I 
am not knowledgable enough to know for sure. I am really hoping that 
someone on this mailing list can provide some feedback and/or hints. I 
have aslo read and tried most of the things that can be found by 
googling for the problem's symptoms.

I have struggled for 3 days to get an Acer Vuego S2W 3300U working 
properly on my SuSE 9.3 Pro box. Along the way, I upgraded my sane 
package to packman's 'sane-1.0.16-0.pm.5.i586.rpm' package.

Here is what happened so far:

1) I tested the scanner in Windows XP and it is working fine. It is 
detected by Windows as an "Acer FlatbedScanner_21".

2) I downloaded the firmware from 
'ftp://12.145.38.159/scanner/drivers/usb/mirascanv403u10_bqa.zip' and 
installed the file 'u176v046.bin' in /etc. I also did a 'chmod 777 
/etc/u176v046.bin', just for kicks, to be dead sure.

3) I then configured /etc/sane.d/snapscan.conf as follows:
---
firmware /etc/u176v046.bin
/dev/usb/scanner0 bus=usb
---

4) I started Yast2, and invoked the yast2-scanner module (Hardware -> 
Scanner). It detected the scanner as 'Acer FlatbedScanner 21'. So far so 
good! I closed Yast.

5) Time to test the scanning. I started kooka (my favourite sane client) 
as root, and everything works fine (the sane project did a fantastic 
job, thanks!).


Now, for the weird stuff that followed after that...

If I unplug the scanner's power source, or the scanner's usb cable, and 
then reboot the computer, and then plug in in again, the following happens:

1) The scanner is detected as an 'Acer FlatbedScanner_13'. This is a 
problem, because it does not work unless it is detected as an 'Acer 
FlatbedScanner_21'. After this point I can try whatever I want, the 
scanner is never detected as an 'Acer FlatbedScanner_21' again, only as 
an 'Acer FlatbedScanner_13'. In short, when the scanner is detected as 
an 'Acer FlatbedScanner_13', it never works. If it is detected as an 
'Acer FlatbedScanner_21', it always works.

2) The only way I can get the scanner to be detected as an 'Acer 
FlatbedScanner_21' again, is to plug it into a Windows machine... Then 
the following happens:

a) Windows announces that it found an 'Acer FlatbedScanner_13', but 
immediately afterwards, Windows announces that it found an  'Acer 
FlatbedScanner_21', and that it is installed and ready for use.

b) Then the scanner works fine in Windows.

c) Interestingly enough, when the scanner is then plugged back into my 
SuSE 9.3 Pro box, it is detected as an 'Acer FlatbedScanner_21' again, 
and then it works perfectly!

As I mentioned, I am not a hardware guru at all (I am hoping someone 
here is!), but I can try to summarize the whole weird situation as follows:

* Windows gives some instruction to the scanner, causing it to identify 
itself as an 'Acer FlatbedScanner_21' (is this even possible?). As long 
as it is detected as an 'Acer FlatbedScanner_21' by Linux, everything 
works fine. No problems up to this point.

* When the scanner is powered of, or unplugged, and later re-connected 
to my Linux box, it can only be detected as an 'Acer FlatbedScanner_13'. 
I cannot get it to work in Linux then.

* To 'reset' the scanner, so that it can be detected as an 'Acer 
FlatbedScanner_21' again, I need to plug it into a Windows computer. If 
it is then connected to my Linux box again, it is detected as an 'Acer 
FlatbedScanner_21', and it works perfectly again.

What on earth can I do to make sure that the scanner is *always* 
detected as an 'Acer FlatbedScanner_21' by Linux, even if it (the 
scanner) is powered off or unplugged? I do not always have a Windows 
computer nearby to 'reset' it. Is this behaviour a bug in sane or snapscan?

Thank you for your time!

Kind Regards,
Werner