USB-C UCSI GET_CABLE_PROPERTY Errors on Boot

Summary

On Linux kernel 6.9 and later, Framework laptops produce ucsi_acpi error messages during boot and whenever a USB-C device is plugged or unplugged. The errors — unknown error 0, unknown error 256, GET_CABLE_PROPERTY failed (-5), and UCSI_GET_PDOS failed (-5) — originate from a kernel feature that queries USB-C cable properties via the UCSI (USB Type-C Connector System Software Interface) ACPI interface¹². Framework's firmware does not pass cable property information correctly to the kernel, causing the queries to fail³⁴. The messages are cosmetic in most cases and do not affect USB functionality, though some users report related issues with external monitors and power delivery negotiation⁵⁶.

Symptoms

• Error messages in dmesg / journalctl on boot¹⁷:

  ucsi_acpi USBC000:00: unknown error 0
  ucsi_acpi USBC000:00: GET_CABLE_PROPERTY failed (-5)
  ucsi_acpi USBC000:00: unknown error 256
  ucsi_acpi USBC000:00: GET_CABLE_PROPERTY failed (-5)

• UCSI_GET_PDOS variant on some configurations⁵:

  ucsi_acpi USBC000:00: UCSI_GET_PDOS failed (-5)

• Errors triggered on plug/unplug — inserting or removing expansion cards, chargers, or USB-C devices produces additional error messages¹⁸
• PME spurious native interrupt may appear alongside the UCSI errors when plugging in a charger¹
• External monitors may not be detected via USB-C on some systems (may be a separate issue)⁶⁹
• EPR (240W) charging may fail because the kernel cannot read the cable e-marker to confirm 5A capability¹⁰

Affected Models

• Framework Laptop 13 (AMD Ryzen 7040 Series) — most commonly reported¹⁷¹¹
• Framework Laptop 13 (AMD Ryzen AI 300 Series)¹²
• Framework Laptop 13 (Intel Core Ultra Series 1) — some reports⁵
• Framework Laptop 16 (AMD Ryzen 7040 Series)¹¹¹
• Framework Laptop 12 — at least one report¹³

The issue is not exclusive to Framework — the same UCSI errors have been reported on other AMD-based laptops¹⁴.

Root Cause

Linux kernel 6.9 introduced a patch by Jameson Thies (Google) that queries GET_CABLE_PROPERTY via the UCSI ACPI interface to register USB-C cable details (plug type, cable type, revision) in sysfs (/sys/class/typec/)². On Framework laptops, the PD (Power Delivery) controllers respond with error codes 0 and 256 instead of valid cable property data, causing the kernel to log the failure¹³.

Framework's Daniel_Schaefer (Framework Software Engineer) explained the architecture⁴:

• Framework laptops use separate PD controllers — one for each side (managing two ports each) — rather than implementing PD logic in the EC (Embedded Controller) like most Chromebooks
• The UCSI subsystem in the OS communicates through ACPI (BIOS) to the EC, which passes messages through to the PD controllers and back
• The kernel UCSI driver expects Chromebook-like behavior where the EC handles PD natively, but Framework's PD subsystem is implemented differently
• The errors are the kernel trying to retrieve non-vital Type-C cable and port information (used for informational popups about cable capabilities), not core USB functionality

Heikki Krogerus (Intel, UCSI maintainer) confirmed on the linux-usb mailing list that the interface claims the Cable Details feature is supported but clearly does not return correct data, and indicated this should be reported to AMD¹⁵.

Framework engineer JohnAZoidberg stated³:

"The UCSI error messages mean that the kernel is unable to figure out the cable properties. Our firmware currently does not pass this information correctly to the kernel. We have fixed this for some cases but some more cases remain."

Diagnosis

1. Check for UCSI errors:

   sudo dmesg | grep ucsi_acpi

2. Check journal for error timeline:

   journalctl -b | grep ucsi_acpi

3. Verify kernel version — the errors started appearing in kernel 6.9¹:

   uname -r

4. Test with expansion cards removed — removing all non-USB-C expansion cards reduces (but does not eliminate) the errors¹⁷

5. Check if ports still function — test charging, data transfer, and display output on each port to confirm the errors are cosmetic vs. functional⁴

Workarounds & Fixes

Solution	Effectiveness	Notes
Ignore the messages34	Usually sufficient	Framework confirmed the errors are non-functional in most cases — USB-C ports continue to operate normally
Use quiet kernel parameter13	Hides messages visually	Add quiet to kernel boot parameters. Does not fix the underlying issue, only hides console output during boot
Downgrade to kernel 6.8 or earlier17	Eliminates messages entirely	The GET_CABLE_PROPERTY query was introduced in 6.9. Not practical for most users due to security and driver improvements in newer kernels
Keep expansion cards inserted at boot1	Reduces occurrences	Errors appear most often when USB-A, HDMI, or other non-USB-C expansion cards are present during boot
Update to latest BIOS3	May reduce occurrences	Framework has applied partial fixes in newer firmware versions, but some cases remain
Power delivery workaround (for EPR)10	Workaround	If 240W charging fails, try a different USB-C cable or port. The issue stems from the kernel being unable to read cable e-marker data

Resolution

Framework has acknowledged the issue and filed internal engineering tickets⁵⁸. Framework engineer JohnAZoidberg confirmed that partial fixes have been applied in firmware updates but some cases remain unresolved³. There is no complete fix available yet.

The errors are expected to persist until either:

• Framework releases a firmware update that properly responds to UCSI GET_CABLE_PROPERTY queries
• A kernel patch is submitted to handle Framework's non-standard UCSI implementation gracefully

Users experiencing functional issues (monitors not connecting, charging failures) alongside these errors should open a support ticket with Framework, as those may be separate problems⁴⁶.

Related

• [TRACKING] USB C Error on boot — Framework Community (main tracking thread, 95+ replies)
• ucsi_acpi USBC000:00: unknown error 0 · Issue #3 — GitHub (Framework firmware tracker)
• ucsi_acpi USBC000:00: unknown error 256 · Issue #185 — GitHub
• Continuous ucsi_acpi errors on AMD Ryzen AI 300 Series — Framework Community
• GET_CABLE_PROPERTY issue — Linux USB Mailing List — linux-usb
• USB-C Ports Stop Charging — related known problem

Footnotes

1. [TRACKING] USB C Error on boot — Framework Community (Plastic_Knight, Jun 2024) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹

2. [PATCH v4 2/4] usb: typec: ucsi: Register cables based on GET_CABLE_PROPERTY — Jameson Thies, lore.kernel.org (Mar 2024) ↩ ↩²

3. ucsi_acpi USBC000:00: unknown error 0 · Issue #3 — Comment by JohnAZoidberg — GitHub (Mar 2026) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

4. [TRACKING] USB C Error on boot — Comment by Daniel_Schaefer — Framework Community (Jan 2026) ↩ ↩² ↩³ ↩⁴ ↩⁵

5. [TRACKING] USB C Error on boot — Comment by RokeJulianLockhart — Framework Community (Jul 2025) ↩ ↩² ↩³ ↩⁴

6. [TRACKING] USB C Error on boot — Comment by wheezle — Framework Community (Sep 2024) ↩ ↩² ↩³

7. [TRACKING] USB C Error on boot — Comment by Wrybill_Plover — Framework Community (Jun 2024) ↩ ↩² ↩³ ↩⁴

8. [TRACKING] USB C Error on boot — Comment by Matt_Hartley — Framework Community (Jan 2026) ↩ ↩²

9. [TRACKING] USB C Error on boot — Comment by pcoreyster — GitHub (Sep 2025) ↩

10. FW16 AI 300: 240W EPR charging not working · Issue #193 — GitHub (Mar 2026) ↩ ↩²

11. [TRACKING] USB C Error on boot — Comment by arthomnix — Framework Community (Jun 2024) ↩ ↩²

12. Continuous ucsi_acpi errors on AMD Ryzen AI 300 Series — Framework Community (Jul 2025) ↩

13. [TRACKING] USB C Error on boot — Comment by ajb — Framework Community (Apr 2026) ↩ ↩²

14. What do ucsi_acpi GET_CABLE_PROPERTY errors mean? — Unix StackExchange (Jan 2025) ↩

15. Re: GET_CABLE_PROPERTY issue — Heikki Krogerus, linux-usb mailing list ↩