Mailinglist Archive: opensuse (3605 mails)

[Scott Castaline <hscast@xxxxxxxxxxx>]

On Wed, 2006-06-14 at 12:04 +0200, Johannes Meixner wrote:
> Hello,
> 
> On Jun 13 12:20 Scott Castaline wrote (shortened):
> > just out of curiosity, what changed between
> > 10.0 and 10.1 that would affect hplip?
> 
> I don't know what you mean.
> For me both new versions work well both for 10.0 and 10.1.
> 
> For your information:
> 
> There is a usblp<->usbfs/libusb conflict:
> 
> The current HPLIP "hp" backend removes HP USB-printers
> from the USB device list (it uses libusb) so that the CUPS
> usb backend will no longer work with those printers.
> Remember that during startup of cupsd all backends are executed
> so that at the moment no HP USB-printer works with the
> CUPS usb backend if HPLIP is installed.
> 
> According to the HPLIP developers this will change the future:
> -------------------------------------------------------------------------
> HPLIP developer wrote (shortened):
> > > I have fixed this in the "hp" backend for the next release. 
> > > A device discovery in the "hp" backend will no longer remove
> > > the usblp for that URI. But, any other I/O (ie: printing,
> > > toolbox or scanning) will remove usblp for that URI which
> > > would disable the "usb" backend for that URI.
> > 
> > Could you explain why the "usb" backend and the "hp" backend 
> > can no longer co-exist for "real" I/O?
> > 
> > When they cannot co-exist for "real" I/O, there will be the 
> > problem that a queue can be set up using "usb" because it can 
> > detect the printer and a second queue for the same device can 
> > be set up using "hp" because it also detects the device but 
> > then the "usb"-queue stops to work as soon as the "hp"-queue 
> > was used once.
> 
> [...]
> 
> Yes, this is a general kernel problem. You cannot have two different
> drivers (kernel modules) talking to the same USB device. In this case
> usblp and usbfs (ie: libusb). 
> 
> I have talked to Michael Sweet, and he is planning on releasing a
> libusb version of the CUPS "usb" backend. Once both backends
> use libusb the problem goes away.
> -------------------------------------------------------------------------
> 
> 
> Kind Regards,
> Johannes Meixner
> -- 
> SUSE LINUX Products GmbH, Maxfeldstrasse 5      Mail: jsmeix@xxxxxxx
> 90409 Nuernberg, Germany                    WWW: http://www.suse.de/
> 
Thanks for the response. I'm very happy withit status quo since I don't
use the usb interface, but go through the net iface.


-- 
Scott Castaline aka Bad2theBone

Hey, I was born crazy, what's your excuse?!?!

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