Duplicate printers listed when adding HP printer

[Jonathon Conte]

While setting up my HP inkjet printer, I see two slightly different printer names are visible in the list of local, detected printers. However, both items in the list refer to the same printer.

There should be only one list entry for each physical printer.

I'm running Dapper Drake testing (Flight 4 + updates) and have a Hewlett-Packard Deskjet 940c connected via USB 2.0 on an Asus A8N-VM (nVidia GeForce 6100 + nForce 410).

[Jonathon Conte (thesicktwist)]

The same printer is shown twice when setting up a new printer. It isn't clear to the user why this occurs or which printer should be selected from the list of detected printers.

[Daniel Goldsmith (goldsmitharmy)]

A picture of the printer select screen, which shows two of the same printer although only one is attached.

[Pascal De Vuyst (pascal-devuyst)]

This is because 2 CUPS backends can be used for you HP USB printer: the "usb" CUPS-backend provided by cupsys and "hp" backend provided by hplip.

You can view the possible backends for your printer by running this command in a terminal/console:
$ lpinfo -v

Please select the "hp" CUPS backend because this allows you to view the printer ink levels and to do printer cartridge cleaning and alignment with the GUI program hp-toolbox, this is described here: https://wiki.ubuntu.com/HPPrinterInstallation.

According to me the best solution is:
If both a "usb" and "hp" backend are available for a printer gnome-cups-manager should only show the "hp" backend under "Use a detected printer" because of the above mentioned advantages of this backend. This would still allow you to select the "usb" backend under "Use another printer by specifying a port".

Another possible solution is to list both backends as is but to indicate that the "hp" backend is the recommended backend and put this at the top of the list of detected printers (now you need to select the second item in this list).

In both cases this behaviour needs to be changed in gnome-cups-manager.

[laksdjfaasdf (laksdjfaasdf)]

Same here with Deskjet 930C - see attached screenshot.

With reference to my bug entry:

https://launchpad.net/distros/ubuntu/+source/gnome-cups-manager/+bug/32545

[laksdjfaasdf (laksdjfaasdf)]

If I add a printer I get 2 entries.

[Daniel Holbach (dholbach)]

Ubuntu task is pointless, closing.

[Martin Pitt (pitti)]

closing as duplicate of bug #24999

[Pascal De Vuyst (pascal-devuyst)]

@Martin Pitt

This bug is definitely no duplicate of bug #24999.

The problem described here is that there are 2 printer models listed under "Detected printers" which can easily be solved by removing the hplip symlink.

Bug #24999 is about the fact that 2 duplicate drivers are listed in the "Driver" dropdown. The solution for this bug requires changes in gnome-cups-manager.

These are two different things so I'm reopening this bug.

[Pascal De Vuyst (pascal-devuyst)]

I seems I was a little bit confused in my last comment, it should be:

This bug is definitely no duplicate of bug #24999.

The problem described here is that there are 2 printer models listed under "Detected printers" for HP printers. The solution for this bug requires changes in gnome-cups-manager.

Bug #24999 is about the fact that 2 duplicate drivers are listed in the "Driver" dropdown. That bug has been fixed.

[Pascal De Vuyst (pascal-devuyst)]

Michal Suchanek (https://launchpad.net/people/hramrach) wrote:

> When gnome-cups-manager autodetects a
> printer it only shows the printer name, not the
> connection type/backen used.

> This information may be necessary to set up
> the printer properly.

> ie. HP DeskJet printers are shown twice, once
> with usb/lpt backend and once with hp
> backend. The printer only works properly with
> hplip if the hp backend is used.

> When a printer connected to a special backend
> is detected, the window with the list of printers
> should display information on that backend.

> ie when a printer using the hp backend is
> detected the window should show a notice that
> this backend should be used rather than the
> usb/lpt backends because it works with hplip

Michal,

I can agree with you that there should be an indication in detected printers names for special backends to differentiate between several entries, e.g.:
DESKJET 3820
DESKJET_3820 (hplip)

But I don't think it is necessary to have extra information about the backends. CUPS webinterface doesn't provide any extra information either for backends when setting up a printer.
I believe it would be sufficient if gnome-cups-manager just puts the detected printer with hp backend at the top of the list of detected printers and selects this by default (as described before).

Regards,
Pascal

[Ante Karamatić (ivoks)]

In Edgy, detected HP printer apears only once. This is cause of newer HPLIP in Edgy.

[Michal Suchanek (hramrach)]

If there is a choice there should be enough information shown to the user so that he can choose the right option.

The fact that there is already an UI that does not provide sufficient information is not an excuse for providing insufficient, even less information.

If the problem is solved by providing only one option the information is not needed anymore, at least not in the UI.

Thanks

[Pascal De Vuyst (pascal-devuyst)]

Ante wrote:
> In Edgy, detected HP printer apears only once. This is cause of
> newer HPLIP in Edgy.

In Edgy it appears that the cups usb backend is not working anymore, resulting in only one printer entry in gnome-cups-manager from the hplip backend.

Running the following command gives no output:
$ /usr/lib/cups/backend/usb

I seriously doubt this is caused by the newer HPLIP in Edgy, this looks more like a bug in cupsys.
In attachment you find the output of command lpinfo -v which shows that CUPS only detects my printer with the hp backend on Edgy, the usb backend is not present. Perhaps this is a temporarly breakage since Edgy is still in heavy development.
How can people with non HP printers configure their usb printers on Edgy?
Therefore I think the 2 detected printer entries in gnome-cups-manager are necessary, but a user should be able to see a clear difference between similar entries and if a printer that works with the hplip backend is detected it should prefer this entry by selecting it by default.

[Pascal De Vuyst (pascal-devuyst)]

Ok, ignore my previous comment.
This bug is indeed fixed in Edgy.
I have found the upstream debian bug report: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=362437.

Version: 0.9.9-1
Since HPLIP now disables usblp for every printer it manages, the CUPS usb backend doesn't detect it anymore. This bug is not something HPLIP could really fix (it was a CUPS issue, and probably best fixed by CUPS informing which backend would handle the device), but we ended up working around it as a side-effect of the migration to libusb.

[Pascal De Vuyst (pascal-devuyst)]

Reopening this bug.
Unfortunately duplicate printer models are listed again with hplip 1.6.7-2ubuntu1.
This is a major bug since some hplip printers won't work when installed with the default usb backend. There should be an indication for the hplip backend and this should be selected by default as described before.

[Chris Eineke (chris.eineke)]

Pascal,

I'm running the latest Kubuntu/edgy and I can't use USB printers anymore. Do you know if there's a fix?

[Pascal De Vuyst (pascal-devuyst)]

@chris_eineke
I'm not so familiar with Kubuntu for setting up printers.
To find out if your usb printer is detected by CUPS you can run the following command:
$ lpinfo -v
Please open a new bug for your problem to avoid adding unrelated comments to this bug report.

[Pascal De Vuyst (pascal-devuyst)]

Still a problem in gnome-cups-manager on the finally released Edgy, rejecting hplip task.

[Till Kamppeter (till-kamppeter)]

This really cannot be considered a bug of HPLIP, it is a problem of the printer setup tools. See the 4th comment in this bug report, from Pascal De Vuyst at 2006-02-28 21:46:06 CET:

You see the printer twice as it is once directly detected by CUPS through its "usb" backend and once via HPLIP via the "hp" CUPS backend.

If you run "lpinfo -v" or use the CUPS web interface (http://localhost:631/admin/) you will also see two entries for your printer.

In the CUPS web interface you can clearly distinguish the two entries, all printer setup tools should do so, as it can always happen that more than one CUPS backend can be suitable for one and the same printer. The printer setup tools should also recommend the "hp" backend over "usb" because it supports the special features of HP printers.

gnome-cups-manager is not maintained any more and will be replaced by printerdrake. printerdrake suppresses the non-HPLIP entry. See also

https://blueprints.launchpad.net/distros/ubuntu/+spec/printerdrake

[Siegfried Gevatter (rainct)]

Same on Feisty Fawn Herd 4 with HP Photosmart C3180.

I think the best would be list it only once, use hp by default and allow to change to usb in the Properties window once installed.

[Pascal De Vuyst (pascal-devuyst)]

Fixed in Feisty.

gnome-cups-manager (0.31-3ubuntu3) feisty; urgency=low

  * 35_show_more_info_of_detected_printers.patch: Show additional info for the
    list entries under "Detected printers", so that when printers of the same
    model are detected that they can be distinguished, especially HP printers
    which are detected once by the "usb" and once by the "hp" backend.

 -- Till Kamppeter <email address hidden> Sat, 2 Mar 2007 15:47:50 +0000

[Jonathon Conte (thesicktwist)]

With respect to the author of the patch, I do not think that this is the right solution. The new behavior does nothing to help new users figure out why they see their printer listed twice and more importantly, which of the two printers listed should be selected.

While I have no research to back it up, I am willing to bet anything that the average computer user has no idea what "backend" means in the context of software. Furthermore, a user should not be forced to learn how CUPS works in order to set up a printer for the most basic usage. I sincerely feel that this is one of those areas where choice needs to be limited and a sane default picked. Only one entry should be on the list for each physical printer. It is extremely unintuitive for any non-technical user to be any other way.

[Hew (hew)]

Ubuntu Edgy Eft is no longer supported, so a SRU will not be issued for this release. Marking Edgy as Won't Fix.