Scanner permissions.

Asked by Toma on 2006-06-17

Bit of a scanner error. Its a Multifunction Epson Stylus RX530 running on the epkowa driver. Prints fine, scans only under sudo. As you can see, all required files have 666 permissions.
Sane needs to start using /sys IMHO as /proc is outdated right?

$ scanimage -L

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).

$ groups haste
haste : haste adm dialout fax cdrom floppy tape audio dip video plugdev lpadmin scanner admin saned

$ sudo scanimage -L
device `epkowa:libusb:001:002' is a Epson PM-A750 flatbed scanner

$ ls -l /dev/usblp0
crw-rw-rw- 1 root lp 180, 0 2006-06-17 16:20 /dev/usblp0

$ ls -l /proc/bus/usb/001/002
-rw-rw-rw- 1 root root 96 2006-06-17 16:19 /proc/bus/usb/001/002

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Toma (tomhaste) said : #1

WEIRDEST Thing. Certainly filing a bug here. Some crazy reason i needed to change permissions on /dev/bus/usb/001/*

What the heck hey!? Theres a dev of proc...? Im totally dumbfounded by this.

Anyway, a small victory for me! But this is a probem that hopefully gets fixed soon!

Then which group should it be ... scanner or printer?

Note that /proc/bus/usb is deprecated

Note that the apparent permission of this device is likely fixed in edgy -- we added epson to the list of vendors that abused scsi class ids

Toma (tomhaste) said : #4

Fantastic news. The group is set to lp so thats another weird thing. The printer AND scanner share the same /dev entry which is kinda weird IMHO.
I filed a bug against udev for this weird behaivior. Hopefully it gets confirmed and fixed! This is the second scanner that ive had thats got weird permissions. Will also file a bug with SANE and see if they can get the old /proc system taken out back and put out of its misery.

Galileon Galilei (galileon) said : #5

i have a canon pixma mp150, which does the same - needs a sudo xsane to run properly, otherwise it complains about permissions

can anyone tell me if its possible to set this permission please? thanks!

Ian Hilliard (i-hilliard) said : #6

I just had the same problem with an Epson Perfection V10.

The solution is to put the scanner signature into the file /etc/udev/rules.d/45-libsane.rules

For the V10 scanner, the line looked like this:

# Epson Perfection V10
SYSFS{idVendor}=="04b8", SYSFS{idProduct}=="012d", MODE="664", GROUP="scanner"

The result of this line is that the group is set to scanner. It is therefore important that all the users that need to use the scanner belong to this group. That can be done by putting the username into the /etc/group file into the group scanner.

Once that is done, providing that the driver has been installed, there should be no problem scanning.


to find the {idVendor} and {idProduct} use the sane-find-scanner program.

To find the {idVendor} and {idProduct} use the sane-find-scanner program.