[sane-devel] sane-backends 1.0.14 and Epson Perfection 1250 and 1260 trouble

[Henning Meier-Geinitz]

Hi,

On Sun, Jun 06, 2004 at 09:25:29AM -0400, Karl Heinz Kremer wrote:
> The Epson backend does not have information about these scanners (this
> means no product ID),

You mean: no internal product id?
The USB product id of these scanners are actually listed in your code.

> so they should not be recognized and therefore
> the backend should not try to send any data. The only way this would
> happen is, if somebody explicitly uses the "usb 0x4b8 0xXXX" entry in
> epson.conf to manually add this scanner to the list of known scanners.

I'll try to understand what happens: "usb" is in epson.conf so
sane_init() calls attach_one_usb(). By the way, the attach_string
related code seems to be unused in that function. Now attach() is
called. As isLibUSB is false and dev_name is empty, for every known
device sanei_usb_find_devices() is called. As The 1260 and 1250 are
known (see epson_usb.conf) attach_one_usb() and attach () is called
again, this time with the full libusb name. There is another test if
the scanner is in the list of ids and it actually is. After that,
commands like reset() and get_identity_information() are sent to the
scanner. These commands will crash scanners that don't speak the epson
protocoll.

I may have missed something in this analysis, however.

So the ids of these scanners should just be removed from epson_usb.c.

> I don't have these scanners, so I cannot test this. I do however know
> that if I add an EPSON scanner that is not yet supported (this was e.g.
> the case with the Perfection 4850), the new scanner is not recognized,
> and skipped during the scanner detection.

Maybe you added it to epson_usb.c but in epson.conf there was no
"usb"? Or the scanner just didn't mind being sent some epson protocol
commands?

> There may be something else doing on, but I don't know what yet.
> 
> I need a debug log for this case to find out what's going on. 
> Unfortunately
> the author of the bug report did not leave an email address, so I hope
> that either my comment in the bug database, or this mail reaches the
> author.
> 
> Henning, do you know how to get in touch with Jan?

No. But as he has responded to my previous questions I guess he reads
the bug tracker from time to time.

By the way: there are some other bug/wish list reports for your
backend that could use some comments (or fixes if possible):

https://alioth.debian.org/tracker/index.php?group_id=1308&atid=410366

Thanks,
  Henning