Comment 6 for bug 842823

Note that CUPS itself does not support very many printer types. It has some sample drivers for common languages like PCL, but the mass of printer drivers are separate packages: HPLIP, Gutenprint, foo2zjs, SpliX, ... Drivers which are free/open source software ship with Ubuntu, proprietary/closed-source drivers we usually cannot ship. The many Canon printers supported out-of-the-box by the Ubuntu Linux distributions are not CAPT-based, these are PostScript (supported by PostScript PPD files) and PCL (supported by Ghostscript's built-in drivers and by HPIJS) laser printers and also inkjet printers (supported by Gutenprint).

CAPT-based laser printers need a proprietary driver from Canon. This driver does not fit very well with the many different Linux distributions. Perhaps it is even older and did not get updated for recent changes in the printing infrastructures. The PPA packages try to adapt the drivers as well as possible to the recent changes in the Ubuntu distribution.

Problem now is that the Canon driver package does not only ship a filter to generate CAPT output from the print job data but also a CUPS backend to communicate with Canon's printer. This backend uses the usblp kernel module and not libusb.