On Wed, Sep 7, 2022 at 10:38 AM Jonathan Ryshpan <jonrysh(a)pacbell.net
wrote:
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(a)pacbell.net
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.
In addition to getting printer capabilities, CUPS needs to send setup data
(e.g., non-duplex request) to
the printer followed by the print data. The problem for troubleshooting
with USB is that some cleanup is
needed after a failed job/test.
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?
TCP/IP is used on ethernet cables and WiFi. Ethernet generally requires a
router with DHCP. Typical
home internet these days provides a combined modem/router with both wifi
and ethernet, so if you
are using wfi you might have to move the printer close enough to the router
to connect ethernet.
Wireless is also supported by your printer. Apple Airprint was invented to
allow iPhone and iPad
users to print directly to a printer, This makes my partner (and the stores
that provide printer supplies!)
very happy. Use whatever your network provides.
> 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
It is possible that HP has some special sauce for USB printing, but to be
certain you probably
need the help of the ipp-usb exports via their github Issues.
--
George N. White III