PLD Linux Distribution

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====== Scanners ======
Configuration of scanners in PLD 

===== Installing packages =====
Main packages: 

<file>poldek:/all-avail> install sane-backends xsane
</file>


===== Configuration of scanners on USB bus =====


==== Finding scanner device ====
Display devices currently on USB bus (use sudo or make sure user in is usb group): 

<file> /usr/sbin/lsusb
</file>
Plug in scanner, check ///var/log/kernel// for sth similar to: 

<file>Apr 15 10:34:27 laptop-hp kernel: [ 8122.892835] usb 2-1: new full speed USB device using ohci_hcd and address 4
Apr 15 10:34:27 laptop-hp kernel: [ 8123.078105] usb 2-1: New USB device found, idVendor=055f, idProduct=021b
Apr 15 10:34:27 laptop-hp kernel: [ 8123.078115] usb 2-1: New USB device strings: Mfr=0, Product=1, SerialNumber=0
Apr 15 10:34:27 laptop-hp kernel: [ 8123.078122] usb 2-1: Product: USB Scanner
Apr 15 10:34:27 laptop-hp kernel: [ 8123.078422] usb 2-1: configuration #1 chosen from 1 choice
</file>
or run lsusb again and notice new device. 



==== Testing if sane recognizes scanner ====
Run (first from user account and later via sudo) 

<file>sane-find-scanner
</file>
One should see: 

<file>found USB scanner (vendor=0x055f, product=0x021b, chip=GT-6816?) at libusb:002:004
</file>
If there is also information 

<file>libusb couldn't open USB device /dev/bus/usb/002/004: Permission denied.
libusb requires write access to USB device nodes.
</file>
meaning there is privilages problem  



==== Solving /dev/bus/usb/*/* privilages problem ====
If device being scanner has root:root privilates: 

<file>crw-rw-r-- 1 root root 189, 131 Apr 15 10:43 /dev/bus/usb/002/004
</file>
regular users will not be able to use scanner device. 

Option is adding new udev rule to file ///etc/udev/rules.d/41-libsane-local.rules// which will deal with adding scanner device. 

Selection criteria can be found from issuing command (after using proper usb bus numbers 2.4 in example): 

<file>udevadm info -a --name /dev/usbdev2.4 
</file>
or monitoring udev events (with properties display) during device plugin 

<file>udevadm monitor --property
</file>
Most likely criteria would be SYSFS{idVendor}== and SYSFS{idProduct} so rule migh look like: 



<file>SYSFS{idVendor}=="055f", SYSFS{idProduct}=="021b", MODE="0664", GROUP="scanner", ENV{libsane_matched}="yes"
</file>
Reload udev rules: 

<file>udevadm control --reload-rules
</file>
and unplug, plug device or trigger all rules again: 

<file>udevadm trigger
</file>
and verify results. 

Note that we here try to use non-existing in PLD group 'scanner' but somehow rule works for me (udev-151, kernel-2.6.32.8) and something (TODO: what? by what criteria ?) adding currenly logged in on Xconsole user ? to device acl, so  'getfacl /dev/bus/usb/003/009' returns: 



<file># file: 003/009
# owner: root
# group: root
user::rw-
user:matkor:rw-
group::rw-
mask::rw-
other::r--
</file>
and device is accesible (rw) for user 'matkor'. 

Of course if above does not work, one can select any group 'usb', 'users' etc to be added for device. 



==== Firmware files needed for scanner models ====
Sometimes firmware file must be loaded to scanner before using it but required file(s) are not included with sane and must be downloaded from drivers/webpages. Run xsane from console and observere which files seems be needed for given scanner device. 



==== Clients: xsane ====