Both the lp and the usblp driver create devices named lp[n], though the kernel messages suggest an usblp[n] device for the USB printer.
When both a parallel port printer and an USB printer are attached they will both be called lp0 leaving the system with only one device node. (So one of the printers will be missing) So far the best way to make a distinction seemed to be filtering on subsystem in udev, e.g.: # printers KERNEL=="lp[0-9]*", SUBSYSTEM=="printer", NAME="printer/lpt%n" KERNEL=="lp[0-9]*", SUBSYSTEM=="usb", NAME="printer/usb%n" This way parallel port printers will be called 'printer/lpt[n]' and USB printers 'printer/usb[n]'. If my understanding of the matter is correct, parallel and USB printers use different device registration. In my opinion they should either use the same device registration, so when a printer (either parallel port or USB port) is detected it becomes lp0 and when later on another printer (no matter what kind of port it's attached too) is detected it becomes lp1. Or they should have different names so they can be distinguished easily. It doesn't seem handy to have an identical name for devices with different major number and the same minor number. In the usblp driver it seems that usblp_class uses the "lp%d" name even though throughout the usblp driver USB printers get referenced as "usblp%d". I'm not sure if there's a good reason for that or whether it should be fixed. (I'm looking at linux kernel 2.6.16.16) _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
