Bug#909208: ippusbxd: The purpose of recommending system-config-printer-udev?

[Brian Potkin <brian@copernicus.org.uk>]

On Thu 20 Sep 2018 at 08:44:48 +0200, Till Kamppeter wrote:

> On 19/09/18 20:07, Brian Potkin wrote:
> > When hplip is not installed, my ENVY 4500 gets set up as an IPP-over-USB
> > printer very nicely. With hplip installed, plugging the USB cable into
> > the machine before starting ippusbxd gets me a non-driverless queue. Why
> > should I want that?
> > 
> 
> This is done to assure that the scanners in HP's multi-function devices
> work. With a driverless setup the scanner would not work. This is also why
> ippusbxd recommends system-config-printer-udev.

Thanks. I probably would never have deduced that.

> In one or two years we will probably have devices with IPP driverless
> scanning though (the standard is already defined by the PWG, only there is
> no appropriate device on the market yet).

I had noticed that, although 'scanimage -L' returned a URI, 'scanimage >
image.pnm' could not open the scanner device. What extra is required on
the device before it can be marketed as "scanner-capable" with IPP-over-
USB?

> > Furthermore, the non-driverless queue is shared. It seems a little
> > unusual to provide access to the printer when the ippusbxd queue doesn't
> > specifically allow it.
> 
> It seems that CUPS shares a new printer by default and that
> system-config-printer-udev does not explicitly set them not shared.

I too think that is the case if 'cupsctl --share-printers' is set.

Regards,

Brian.