Red Hat Bugzilla – Bug 131945
sane-backends not available to users
Last modified: 2007-11-30 17:10:48 EST
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2)
Description of problem:
sane-frontend applications (xsane, kooka, scanimage -L) do not find a
scanner when run by user. At the same time, the superuser may run them
correctly. The particular scanner is a parallel-port Plustek 9636T.
The user has an UID number 500, and belongs to a group with gid number
1000 ("users"). The relevant files (etc/sane.d/*, /usr/lib/sane/*)
seem to have proper permissions (read for all, read and execute for
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Install FC2, set up a group with GID=100, and an user account with
2. Hook up a scanner and get it running. In my case, this required
uncommenting line plustek_pp in /etc/sane.d/dll.conf.
3. run "scanimage -L" as a root and as the user
Actual Results: running "scanimage -L" as root (results in reporting
running as user fails to find any scanners
Expected Results: running as user should also work
it also turned out that the kernel needed to be recompiled to shrink
it somewhat to get the module drivers working; this however appears to
have nothing to do with the access problem, similar symptoms occur in
any of the kernels I try (2.6.5, 2.6.7, 2.6.8)
Running the standard distribution kernel, as well as any of the upgrades
causes problems with module drivers: vmware 4.5.2 loses access to a
CD-ROM, plustek_pp scanner gets into a dead loop (moving sensor back &
forth) while prescanning, sound chip (VIA 8233, ALSA drivers) produces
only thrashing voices. These problems cease after kernel recompilation
with some options turned off.
You need to power the scanner off, and then on, *after* you log in at
the console. This is because the new 2.6 kernel no longer provides
the old access method. This is a known limitation of Fedora Core 2,
and will be addressed in a future release.
*** This bug has been marked as a duplicate of 121511 ***
(You pointed out that this is a parallel port scanner not a USB one.)
You'll have to change the permissions on /dev/ppdev*, or set up
/etc/security/console.perms to do so for you.
As far as I'm aware parallel port scanners have never been available
to the console user without some other action being taken.
You shouldn't need to recompile the kernel.
I describe the final solution below.
Situation: neither /dev/ppdev* was present on my system nor there was
a relevant device in the /etc/security/console.perms. The scanner
backend (sane-plustek_pp) was using /dev/parport0.
The kernel recompilation mentioned in the mail above was taken as a
remedy to an apparently separate problem (kernel too large or too many
space used by modules). It also worked OK.
If you happen to have a parallel-port Plustek scanner,
1) edit /etc/sane.d/dll.conf, uncomment "plustek_pp" and comment out
2) run "scanimage -L" as root and then as a normal user. If the
scanner is found when attempting as root and not when attempting as a
normal user (the response should read:
device `plustek_pp:parport0' is a Plustek 9636T/12000T parallel port
3) edit /etc/security/console.perms: find line starting with <scanner>
and append /dev/parport0 to the end of it.
4) log out and in as normal user (if working under gdm/kdm, close the
session and log in again).
5) run "scanimage -L". If OK, test your favorite sane frontend.