> I have a HP PSC 1510 all-in-one USB printer that I am trying to install
> in Fedora 4. I also have an old laser printer attached to lpt0. Linux is
> not able to find the USB printer. Do I have to set up USB support first
> or is this already built in? Can some help me with some pointers?
When you do 'ls -l' for your printer device nodes it should give you a clue
what kind of printer you're dealing with.
e.g.: parallel port:
crw-rw---- 1 root lp 6, 0 2006-06-24 17:14 lpt0
the '6, 0' show the kernel's internal device numbering (major/minor number),
it should be different for an USB printer. (I haven't got an example right
If possible you could try to unload the USB printer (usblp) and parallel
port (lp) modules and only load the USB printer module. Check if the
major/minor number changed. It may now be your USB printer.
The following is something I posted to the USB devel list. Unfortunately I
did not get any reaction. I don't know if it applies to Fedora 4 or your
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.:
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
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
I'm not sure if there's a good reason for that or whether it should be
(I'm looking at linux kernel 220.127.116.11)