[sane-devel] classic(linux): sane-find-scanners finds a scanner, but scanimage -L doesn't...

[Branko]

This is getting to be seriously annoying, repetitive PITA.

I have multifunction Canon MP630. Sane used to work fine with its 
scanner, but now after everything went to libusb, I can't make it work.

And this is not the first time and just with this model, it looks more 
like prevailing problem.

There is no troblesshooting help worth speaking about on project's page.

I have found some old claims about need for usbfs mount, but new kernels 
( I am using 3.19.2) don't offer this anymore.

My system is Gentoo 64-bit, I have sane-backends-1.0.24, compiled with 
libusb support. libusb version is 1.0.19.

sane-find-scanner gets me:

"found USB scanner (vendor=0x04a9 [Canon], product=0x172e [MP630 
series]) at libusb:002:004"

but "scanimage -L" immediately after that says:

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).

And yes, I did check canon630u.conf file and enabled canon630u backend 
in dll.conf

canon630u.conf contains one uncommented line:

usb 0x04a9 0x172e

which corresponds to report of sane-find-scanners