SOLVED: CUPS won't print to a brother MFC-8460N

[Markus Stelzhammer]

> > Hi,
> >
> > Would be great if someone could help to come a step further in this problem.
> >
> > I use CUPS version 1.4.6.
> > To save memory, I'm using MDEV instead of UDEV on my system.
> > I already tried with UDEV - this is working - but it need to get it running using MDEV.
> >
> > The strange thing I face:
> > If I run the usb backend by hand, it recogizes the printer:
> >
> > root at ccp511:~# /usr/lib/cups/backend/usb
> > DEBUG: list_devices
> > DEBUG: usb_find_busses=4
> > DEBUG: usb_find_devices=6
> > direct usb://Brother/MFC-8460N?serial=000K7J552309 "Brother MFC-8460N" "Brother MFC-8460N" "MFG:Brother;CMD:PJL,PCL,PCLXL;MDL:MFC-8460N;CLS:PRINTER;" ""
> > root at ccp511:~#
> >
> > So I use usb://Brother/MFC-8460N?serial=000K7J552309 as device URI which was working perfect with udev.
> > But trying to print something leads to the following printer state:
> >
> > root at ccp511:~# lpstat -t
> > scheduler is running
> > system default destination: brother
> > device for brother: usb://Brother/MFC-8460N?serial=000K7J552309
> > brother accepting requests since Wed Oct 19 08:20:06 2011
> > printer brother now printing brother-1.  enabled since Wed Oct 19 08:20:06 2011
> > 	Waiting for printer to become available...
> > brother-1               root            656384   Wed Oct 19 07:54:48 2011
> > root at ccp511:~#
> >
> > I already searched with all the Debug messages in the cups log in the internet but nothing helped so far. here the debugLog:
> >
> > root at ccp511:~# cat /var/log/cups/error_log

> > D [19/Oct/2011:07:54:59 +0000] [Job 1] usb_find_busses=0
> > D [19/Oct/2011:07:54:59 +0000] [Job 1] usb_find_devices=0
> > D [19/Oct/2011:07:54:59 +0000] [Job 1] STATE: +connecting-to-device
> > D [19/Oct/2011:07:54:59 +0000] Discarding unused printer-state-changed event...
> > D [19/Oct/2011:07:54:59 +0000] [Job 1] Failed to set configuration 1 for 04f9:01a5
> > D [19/Oct/2011:07:54:59 +0000] [Job 1] Failed to claim interface 0 for 04f9:01a5: Operation not permitted
> > D [19/Oct/2011:07:54:59 +0000] [Job 1] STATE: -connecting-to-device
> > D [19/Oct/2011:07:54:59 +0000] Discarding unused printer-state-changed event...
> > I [19/Oct/2011:07:54:59 +0000] [Job 1] Waiting for printer to become available...

> >
> >
> > Would be great if someone had an idea what could be the problem here.
> >
> > Greets
> > Markus
> >
>

Finally I found the reason for this problem and I will post it for the case someone else tries anytime to run CUPS with mdev.

The Problem was that the libusb used by the USB backend didn't run as root!! This is no problem when using udev as here anyway a deamon is running for each Interface.
This is not the case with mdev and so the USB backend cannot set the configuration for the interface (see debug info in the cups log).

I solved this issue now by changeing the permissions of all backends in the makefile of the backend folder.


Greets
Markus