Re: Duplex Printer Problem

[Jonathan Ryshpan <jonrysh@xxxxxxxxxxx>]

On Wed, 2022-09-07 at 08:32 -0300, George N. White III wrote:

On Tue, Sep 6, 2022 at 11:46 PM Jonathan Ryshpan <jonrysh@xxxxxxxxxxx> wrote:

For USB, see https://github.com/OpenPrinting/ipp-usb.  The "Issues" section has

examples of troubleshooting on linux:

So there are, but none of them seems to have much to do with my situation.

The problems/printer models aren't the same, but some of the troubleshooting methods

could help pin down the problem.  One reason troubleshooting IPP-USB is hard (quoting the README):

Unfortunately, the naive implementation, which simply relays a TCP connection to USB, does not work. It happens because closing the TCP connection on the client side has a useful side effect of discarding all data sent to this connection from the server side, but it does not happen with USB connections. In the case of USB, all data not received by the client will remain in the USB buffers, and the next time the client connects to the device, it will receive unexpected data, left from the previous abnormally completed request.

Actually, it is an obvious flaw in the IPP-over-USB standard, but we have to live with it.

The easy workaround would be to switch to a network connection.   Opening an issue on the ipp-usb

github site takes effort, but could be a useful contribution to the community.

This implies that cups needs to communicate with the printer to find out something (say whether the printer has duplex capability), but can't because of communication issues which would be solved if IPP-USB were working properly. A test would be to change the connection to the printer from USB to TCP/IP, i.e. I should disconnect USB, attach Ethernet on the printer, set up the printer for Ethernet and see what happens. Is all this correct?

I suspect that ipp-usb is not going to help because the HP m255dw printer doesn't seem to be supported:

# ipp-usb check
Configuration files: OK
No IPP over USB devices found

-- 

Sincerely Jonathan Ryshpan <jonrysh@xxxxxxxxxxx>

	Today's thought:    
	I can please only one person per day.  Today is not 
	your day.  Tomorrow isn't looking good either.

_______________________________________________
users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx
To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx
Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx
Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue