CUPS on Ubuntu 24.04 base: HPLIP backend (hp:/) corrupts image prints, while standard IPP fails for HPLJ and HPENVY
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| cups (Ubuntu) |
New
|
Undecided
|
Unassigned | ||
Bug Description
**System Information:**
* OS Base: Ubuntu 24.04 (via Linux Mint 22.2)
* Printers Tested: HP LaserJet M110w, HP Envy 6420e (both driverless models)
* Connection: Network (Wi-Fi)
* CUPS Version: 2.4.7-1.2ubuntu7.4
* HPLIP Version: 3.23.12+
**Bug Description:**
Multiple modern, driverless HP printers fail to print correctly through two different CUPS backends. The HPLIP backend corrupts the print output, while the standard IPP backend fails to process the job entirely. The issue has been reproduced on both an HP LaserJet M110w and an HP Envy 6420e.
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**Issue 1: HPLIP Backend (`hp:/`) Renders Incorrectly**
* **Setup:** Printers configured with the `hp:/` backend URI.
* **Behavior:** When printing a document containing digital text, or a high-resolution PNG/JPEG image generated from such a document, the output text is rendered in a microscopic, unreadable font. This occurs on both tested printer models.
* **Key Diagnostic:** A PDF created from *scanned* images prints correctly. This suggests a faulty filter within the `hp:/` backend is being triggered by digitally-generated text images, but not by scanned images. The filter attempts to "optimize" the text and corrupts it.
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**Issue 2: Standard IPP Backend (`ipp://`) Fails to Communicate**
* **Setup:** Printers configured with the `ipp://` backend URI and the generic "IPP Everywhere" driver.
* **Behavior:** When a print job is sent, it stalls in the CUPS queue and never reaches the printer. This indicates a communication failure between the CUPS IPP backend and the firmware of these printer models.
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**Summary:**
Users of these HP models are caught between two failing mechanisms on an Ubuntu 24.04-based system: a proprietary backend that corrupts data, and a standard backend that fails to connect. The fact that this affects at least two different models suggests a systemic issue in how CUPS/HPLIP interacts with this generation of HP devices.
