Stéphane, the usblp module can still be the culprit. For example reattaching it after a job can get some printers into an undefined state. Especially if you never observe the problem with the module blacklisted and sometimes observe the problem with the module not blacklisted, the module can have caused your problem. Then you should try a less invasive solution than blacklisting the module, simply preventing the CUPS backend to re-attach the module after a job, via
lpadmin -p Canon_iP4200 -o usb-no-reattach-default=true To remove the setting, run lpadmin -p Canon_iP4200 -R usb-no-reattach You should do very many tests now (aro, as your problem occurs only sometimes. Also always run cancel -a sudo rmmod usblp and then turn off and turn on your printer after each change of the testing mode and after each occurrence of the problem). Try the following three modes (do never use the forced uni-directional mode): 1. Kernel module not blacklisted, no re-attaching module after job 2. Kernel module not blacklisted, re-attaching module after job 3. Kernel module blacklisted -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/995111 Title: Print failure since upgrade to 12.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cups/+bug/995111/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
