On Thu, Aug 16, 2012 at 9:05 PM, m. allan noah <kitno455 at gmail.com> wrote:

> Wireshark makes things a little more difficult, because it shows all
>
the low level USB stuff, that really does not matter to us. So, you
> have to learn to ignore every other packet in those logs, and the
> first 0x40 bytes of the packets you do care about.
>
I'm always startled by the overhead and the layers of indirection involved
in modern protocols.


> I took a brief spin thru your logs, and it appears that the scanner is
> unhappy when we send the 0xd6 command, which I call SET_SCAN_MODE.
>
I tried a simple hack of removing all calls to ssm_do, ssm_buffer and
ssm_cmd.  I was able to get a scan out of the scanner!  However, it came
out at 600 DPI.


> Then we make a series of small area, low resolution scans in the working
> driver, changing one
> parameter each time. Then we see how the calls to the 0xe5 command
> change. It might be that we never determine what they do, or that they
> only do something under the windows driver.
>
FYI : I have a Linux driver from Canon.  It consists of a wrapper around a
binary blob.  This wrapper appears to talk the sane net protocol with the
binary blob.  It also uses a SUID root program to talk with the USB device.

I've done a first batch of tests with --mode --resolution and
--UltrasonicDoubleFeedDetect params.  Unfortunately the binary driver seems
to ignore -x, -y and complains if I use any --Size except A4.  Output,
along with my test script is here:
    http://pied.nu/Sane/canon_dr-20120816-1029.tar.gz

-Philip
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