CUPS & strange USB printers problem

[Chris Smith]

juice wrote:

> Look at this:
> - I,ve got 2 usb printers connected:
>      crw-rw----  1 root 180, 1 sty  1  1970 lp1
>      crw-rw----  1 root 180, 0 sty  1  1970 lp0
> - but something is weird, when I try to localize, which is which:Oct 23
> 12:08:40 [kernel] usb 1-1: new full speed USB device using address 5 Oct
> 23 12:08:40 [kernel] usb 1-1: Product: HP Color Inkjet CP1700 Oct 23
> 12:08:40 [kernel] usb 1-1: Manufacturer: Hewlett-Packard Oct 23 12:08:40
> [kernel] usb 1-1: SerialNumber: SG245311310T Oct 23 12:08:41 [kernel]
> drivers/usb/class/usblp.c: usblp0: USB Bidirectional printer dev 5 if 0
> alt 0 proto 2 vid 0x03F0 pid 0x0312 Oct 23 12:09:23 [kernel] usb 1-2: new
> full speed USB device using address 6 Oct 23 12:09:23 [kernel] usb 1-2:
> Product: hp LaserJet 1300 Oct 23 12:09:23 [kernel] usb 1-2: Manufacturer:
> Hewlett-Packard Oct 23 12:09:23 [kernel] usb 1-2: SerialNumber:
> 00CNBD261757 Oct 23 12:09:23 [kernel] drivers/usb/class/usblp.c: usblp0:
> USB Bidirectional printer dev 6 if 0 alt 1 proto 2 vid 0x03F0 pid 0x1017
> 
> BOTH ARE CONNECTED AS /dev/usb/lp0!!
> does anyone know any kind of solution?
> my box is gentoo with 2.6.8 kernel

Your "ls -l /dev/usb/" shows that they're not both connected as
"/dev/usb/lp0" since you have a "/dev/usb/lp1".

Check the output of "lsusb" and match the ID field with the vid:pid you see
in the log. I don't think "drivers/usb/class/usblp.c: usblp0:" is telling
you what you think it is (but I don't claim to know exactly what the
usblp0: means).

As for CUPS there is no need to worry, as when properly set up it will not
use "/dev/usb/lpx" as the DeviceURI but a logical name such as
usb://HP/color%20LaserJet%203700.

Also, using Gentoo's stock udev rules (I may be assuming too much here)
which printer is lp0 and which is lp1 can easily change depending on
discovery order (I believe the first one seen will be lp0, the next lp1,
etc.). Again this wont trouble CUPS if you're printing to the logical
DeviceURI.

If you want, or need, a stable, always the same, /dev name for them for
other purposes you'll need to write some custom udev rules.

Chris