Comment 8 for bug 1747060

Thanks for the detail, Martin.

> dpkg -l |grep libsane
> ii libsane:amd64 1.0.25+git20150528-1ubuntu2.16.04.1 amd64 API library for scanners

Version 1.0.27 has Debian and Ubuntu bugs for scanners not working filed against it. You are not affected by this.

Printing and scanning are done by different software and one can work and the other not. The two processes are not intimately connected. The printer works because it found by a different process.

I do not think this is a scanner driver problem. You have clearly shown that sane-find-scanner run as root does not detect a scanner. The scanner driver is hpaio (look at /etc/sane.d/dll.d/hplip) and is not used by sane-find-scanner. A user must have permissions given to him to access the USB bus to find the scanner. root doesn't need to be given permissions.

Let us see where a user stands. Plug the device in and do 'ls -l /dev/bus/usb/*/*' as a user. Do you have a line beginning like this "crw-rw-r--+ root lp"? The important thing is the "+". If none of the lines have a "+", log out and log in again.

The end of the line should look like this: /dev/bus/usb/004/005. This is the device file. Now do 'getfacl /dev/bus/usb/004/005'. I get "user:brian:rw-" so I have read-write permissions to the that device file, which is used by the scanner.

Cheers,

Brian.