Scanner works for root but not users

English Hardware
1

Hi,
I just installed Leap 15.0 and I’m trying to get my Samsung SCX-4100 multi-function printer/scanner to work. I installed the Samsung Unified stuff. Printer works fine. I added the scanner in Yast and it see it, but it doesn’t show up in SANE. I ran SANE as root and bingo, it works perfectly. This makes me think it’s a permissions issue. I thought maybe the users need a group. I looked for possible groups such as “scan”, “sane”, and so forth, but I haven’t seen anything that looks like it would work. Do I need to create a group? How would I give that group permissions to the scanner? Am I even on the right track? Thanks.

2

Add

lp

to your user and group might do the trick.

3

Eh, did you reboot ?

4

Thanks, but lp was already there and the users assigned to it. If they’re not assigned to lp, they can’t print. As it is, they can print, but not scan. :frowning:

5

Nice try, but yes. No joy.

6

You’re likely missing a udev rule to assign the appropriate device ownership.

7

The Samsung unified driver should already include a suitable rule for a USB-connected device. Even though I don’t own such hardware, I installed the driver in order to assist another user a few weeks back. I have /etc/udev/rules.d/54-smfp_samsung.rules, which has an entry for the SCX-4100 chipset…

ATTRS{idProduct}=="3413", ENV{libsane_matched}="yes"

and a common part to assign r/w access to the ‘lp’ group for the device node concerned…

ENV{libsane_matched}=="yes", OWNER="root", MODE="664", GROUP="lp"

FWIW, the sane-backends package also provides /etc/udev/rules.d/55-libsane.rules, which contains a rule for this model as well…

# Samsung SCX-4100 | Samsung SCX-4100
ATTR{idVendor}=="04e8", ATTR{idProduct}=="3413", MODE="0664", GROUP="lp", ENV{libsane_matched}="yes"

So, as long as the user is a member of the ‘lp’ group, there should be no issues with using the scanner.

Check that the chipset product ID does match perhaps

lsusb
8

As part of the diagnostic process, you could use the lsusb output to determine the bus/device ID of the attached scanner device, then run something like

ls -l /dev/bus/usb/002/003

*Change the values to suit your connected device

This will confirm current device node permissions.

9

Thanks everyone. I got it working. I can’t say for certain how, but my best guess is power cycling the printer fixed it. I did log in and out a couple of times as well, but these were just normal activities, not anything I was doing trying to fix the problem. I had previously logged out and in, even rebooted the machine, to no avail. The only thing that I can think of that I did that was different is turning off the printer. I turned it on again a few minutes ago to try and investigate using more of your suggestions, but when I fired up SANE, it worked. Seems to work for all users, so YAY! Thanks again!

10

Thanks for the update. Good to know that it is working as expected now. :slight_smile: