printer disabled on printer energy saver or cable disconnect

[rhn at fayn.sk]

Hi,

In the past, I meet with following problem :
When i configure usb printer (Lexmark C510) - everything is ok.
But after printer goes to energy saving mode, then usb disconnect appears and i was not able to print until physical disconnection + connection of the usb cable. I tried to look for some help in this forum. Here are many similiar problems, but no solution.

After short experiencing i found this solution (perhaps - not best, but working):

with dev file system on disconnect are deleted devices /dev/usb/lp[0-n]
according to printer number ( mostly /dev/usb/lp0 ).
with cups printer configured to this device cups usualy write message no such device and disable this printer.

solution:
create device manualy (for lp0) - mknod /dev/usblp0 c 180, 0
                      (... lp1) - mknod /dev/usblp1 c 180, 1
set appropriate privileges      - chown root.lp /dev/usblp0
                                - chmod 0660 /dev/usblp0
configure cupsd to this device  - lpadmin -p lexmark -v usb:/dev/usblp0

Even after unload of usblp driver, when cups try to access this device (somebody is printing) - coresponding kernel drivers are loaded (require kernel module loading but most modern distributions use this feature) and printing is working.

Good luck

Rasto