HP Laser MFP 135ag works just fine with ipp-usb, but is blacklisted

[luqasn]

Hi, I am wondering what the reason is for it being blacklisted?
I unblacklisted it and it works wonderfully. Maybe there are multiple hardware or software revisions of this printer?

Is there something I can test for you in order to get it un-blacklisted?

[alexpevzner]

Are you sure that this device actually works via ipp-usb? What the ipp-usb status command prints?

Historically, HP Laser MFP 135ag was the first printer in my experience, that announced the IPP over USB support (by implementing 7/1/4 USB interfaces) but actually responded "404 Not found" status to all HTTP requests sent into these interfaces. This gave me an idea, that blacklisting facility needs to be implemented.

Later I've added automatic blacklisting of devices, that announce IPP over USB interfaces but actually don't work. So this is possible that even being un-blacklisted in the configuration files, this printer is automatically detected as incompatible and ignored (so letting legacy driver to attach to it).

[ValdikSS]

@alexpevzner HP Laser MFP 135a is AirPrint-certified, while Laser (printer) 107a/108a is not (107w/108w is).
It should work with ipp-usb.
Color Laser 150a is also not certified (w is).

[ValdikSS]

@luqasn, @alexpevzner, do you have a firmware version for which it does work and for which it does not?

[luqasn]

lucas@lucas-framework> sudo ipp-usb status
ipp-usb daemon: running
ipp-usb devices:
 Num  Device              Vndr:Prod  Port  Model
   1. Bus 001 Device 052  03f0:f22a  60000 "HP Inc. HP Laser MFP 135a"
      status: OK

This is after manually un-blacklisting it (by deleting blacklist.conf). I can print just fine with it now via ipp-usb (thanks for this great piece of software btw!).

System Firmware Version of the printer is V3.82.01.07 JULY-13-2019
Engine Firmware Version is V1.00.06 04-01-2019

[alexpevzner]

OK. Looks like it depends on firmware version. Or, may be, on device settings.

I will try to un-blacklist it in the next release of the ipp-usb. Hope that it will automatically detect non-compatible devices and will not prevent proprietary driver from working with them.

Regarding AirPrint certification, unfortunately, it sometimes happens that device listed in that list, actually appears to be incompatible. The same is true for the Mopria certification and for the IPP.Everywhere certifications (actually, all 3 protocols are very similar and have very similar requirements with minor differences in few details, and devices typically support them all together. Or doesn't support all 3).

[alexpevzner]

@ValdikSS,

@luqasn, @alexpevzner, do you have a firmware version for which it does work and for which it does not?

Unfortunately, not. It was a 5-years-ago story, I don't remember all details. And there is no corresponding GitHub issue with all details recorded, shame on me :(

[ValdikSS]

And there is no corresponding GitHub issue with all details recorded, shame on me :(

This one I suppose?
alexpevzner/sane-airscan#68
We can't get the firmware version from there unfortunately. But the logs indeed show error 404.

[alexpevzner]

This one I suppose?

Exactly, thanks!

Firmware version is not guessable from the information we have, unfortunately.

There also may be difference in device settings. The relevant settings may be very non-obvious to guess.

Just as example, some of Lexmark devices don't enable IPP over USB before network stack is configured (even if you don't plan to use it). Probably because IPP over USB inside the device works as reverse proxy that redirects all incoming requests to the internal HTTP server, which doesn't start before network configuration is completed.

[ValdikSS]

Well "a" models are USB-only (no Ethernet or Wi-Fi), so we could only guess.
I checked the earliest firmware I have, HP_Laser_135_V3.82.01.02, and there's support for PWG/UNIRAST/PCLm in the firmware code.