Arch Linux

archibutor

Member

Registered: 2010-09-08

Posts: 7

CUPS doesn't see /dev/bus/usb/x/x printer, no "lp"-group permissions

Symptoms:
After upgrading to systemd on ArchLinux, I could no longer print. CUPS Web Interface said "Waiting for the printer to become available". I removed the printer and tried to add it. Couldn't see it anymore.

Debugging:

[root 002]# lsusb
...
Bus 002 Device 014: ID 04f9:0182 Brother Industries, Ltd Composite Device

[root ~]# cd /dev/bus/usb/002
[root 002]# getfacl 014
# file: 014
# owner: root
# group: scanner
user::rw-
user:maggot:rw-
group::rw-
mask::rw-
other::r--

CUPS Web Interface -> Administration -> Add Printer = Empty "Local Printers:"

I set group lp to have read&write permissions:

[root 002]# setfacl -m group:lp:rw 014
[root@nullfox 002]# getfacl 014
# file: 014
# owner: root
# group: scanner
user::rw-
user:maggot:rw-
group::rw-
group:lp:rw-
mask::rw-
other::r--

Now CUPS Web Interface ->  Administration -> Add Printer = Local Printers: "Brother DCP-7010 (Brother DCP-7010)"

My question:
Why the device node has only scanner-group permissions, and not lp-group? If/when you need more information, please ask.

Additional information:
Installed packages that I think are relevant:

local/systemd-sysvcompat 195-2 (base)
    sysvinit compat for systemd
local/sysvinit-tools 2.88-9
    Linux System V Init Tools
local/systemd 195-2
    system and service manager
local/systemd-sysvcompat 195-2 (base)
    sysvinit compat for systemd

EDIT: Corrected wrong path in title.

Last edited by archibutor (2012-11-09 16:28:38)

aaronmueller

Member

Registered: 2012-08-25

Posts: 15

Website

Re: CUPS doesn't see /dev/bus/usb/x/x printer, no "lp"-group permissions

I have exactly the same problems with my Brother DCP7030.

$ls -al /dev/bus/usb/003/002
crw-rw-r-- 1 root scanner 189, 257 Feb 18 21:47 /dev/bus/usb/003/002

If I chgrp the device to lp all works fine.
What can I do to set this permanently?

Last edited by aaronmueller (2013-02-18 21:10:28)

cfr

Member

From: Cymru

Registered: 2011-11-27

Posts: 7,132

Re: CUPS doesn't see /dev/bus/usb/x/x printer, no "lp"-group permissions

Which groups are you in?

Is polkit correctly installed and running?

I don't think you should need to be in the lp group to print. As I understanding *being* in groups such as lp, audio etc. can actually cause problems with systemd.

If you are maggot, for example, you should be fine. And if not, something is not quite right about your user session.

Last edited by cfr (2013-02-18 23:45:20)

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