cups libusb permissions

[DJ Lucas]

CUPS no longer support access via usblp module and requires libusb in order to use USB printers. Need to review udev rules permissions for /dev/bus/usb/*/*. See thread starting here: ​http://archive.linuxfromscratch.org/mail-archives/blfs-dev/2010-September/020617.html

[ken@…]

I saw the thread, but I wasn't in front of a suitable system to compare it. Now that I am, I think something is missing. In my case, I'm printing with cups, gutenprint, ghostscript to an epson 360 [usb] using a module for the usb lp printer. This is on LFS-6.7.

This printer has always loaded usb_storage, which is probably just a curiosity, but after printing I have

ken@ac30 ~ $lsmod
Module                  Size  Used by
usblp                  10412  0 
usb_storage            42679  0 

and sys.log shows the following (turned it on, printed, turned it off)
Sep 28 14:49:08 ac30 kernel: usb 1-1: new high speed USB device using ehci_hcd and address 3
Sep 28 14:49:08 ac30 kernel: scsi5 : usb-storage 1-1:1.0
Sep 28 14:49:08 ac30 kernel: usblp0: USB Bidirectional printer dev 3 if 1 alt 0 proto 2 vid 0x04B8 pid 0x082C
Sep 28 14:49:09 ac30 kernel: scsi 5:0:0:0: Direct-Access     EPSON    Stylus Storage   1.00 PQ: 0 ANSI: 2
Sep 28 14:49:09 ac30 kernel: sd 5:0:0:0: Attached scsi generic sg2 type 0
Sep 28 14:49:09 ac30 kernel: sd 5:0:0:0: [sdb] Attached SCSI removable disk
Sep 28 14:50:19 ac30 kernel: usb 1-1: USB disconnect, address 3
Sep 28 14:50:19 ac30 kernel: usblp0: removed

I have been vaguely aware of this since Greg KH first mentioned it on lkml in about April, and at that time I assumed it must be a cups-1.4 issue. But, as far as I can remember, I *haven't* had to change kernel config or udev rules, I don't have libusb installed, but I *do* add a udev rule (24-usblp) to create /dev/usb/lp0, and I add an lp user

LFS _used_ to create that rule when we had our own voluminous rules, but it seems to have dropped out now we are following upstream in udev. Funnily enough, I had to add it to my scripts when I was building on CLFS, and I had assumed the test to see if it was needed would fail - that is, until I checked it today. .

[Randy McMurchy]

Updated milestone to 6.7

[ken@…]

Andy added some text to the cups page for this in r9133, telling people who wish to use cups with libusb to disable support in the kernel and omit "--disable-libusb".

[bdubbs@…]

Milestone current deleted