Sorry, HPLIP uses libusb/usbfs instead of usblp. Libusb uses the "/dev/bus/usb/xxx/xxx" device node instead of the "/dev/usblp0" device node.
Since usblp and libusb cannot claim the the same usb device, any HPLIP device I/O usage (ie: scanning, printing or faxing) will remove usblp from the "/dev/usblp0" device node. If you are using CUPS this means in general you should always use the HPLIP's "hp" backend (ie: "hp:/usb/...") instead of the standard CUPS "usb" backend (ie: "usb://..."). The "hp" backend will always use the libusb device node. If you try to use the "usb" backend the "/dev/usblp0" device node may not be available. Currently hal_lpadmin calls hp-info and hp-probe which are io intensive and will interfere with hp-firmware download for the LJ1018 and LJ1020. Because of this interference HAL will not see these printers at plug-in- play time and disable the print queue. The hp-info and hp-probe calls in hal_lpadmin should be replaced with the hp-makeuri call. The udev sysfile information will provide the usb "bus" and "device" information necessary for the "hp-makeuri bbb:ddd" command. Hp-makeuri will return a valid HPLIP uri if the usb device is supported by HPLIP. Hp-makeuri is a light weight call that has very little io overhead. The hp-makeuri command will not interfere with the hp-firmware download. -dave -- cups printjobs unload /dev/usblp0 https://bugs.launchpad.net/bugs/162016 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
