ucsi_acpi USBC000:00: unknown error 256

[mvysny]

Device Information

Framework 13 AMD Ryzen AI 9 HX 370, Ubuntu 25.10 on kernel 6.17.0-14-generic

System Model or SKU

Please select one of the following

• Framework Laptop 12 (13th Gen Intel® Core™)
• Framework Laptop 13 (11th Gen Intel® Core™)
• Framework Laptop 13 (12th Gen Intel® Core™)
• Framework Laptop 13 (13th Gen Intel® Core™)
• Framework Laptop 13 (AMD Ryzen™ 7040 Series)
• Framework Laptop 13 (AMD Ryzen™ AI 300 Series)
• Framework Laptop 13 (Intel® Core™ Ultra Series 1)
• Framework Laptop 16 (AMD Ryzen™ 7040 Series)
• Framework Laptop 16 (AMD Ryzen™ AI 300 Series)
• Framework Desktop (AMD Ryzen™ AI 300 PRO Series)

BIOS VERSION

03.05

DIY Edition information

If you are experiencing an issue on a DIY system, Please also fill out the memory and storage devices you are using.

Memory: 2x A-data AD5S560048G-SF2 5600 MT/s from Framework
Storage: WD BLACK SN850X 4000GB

Standalone Operation (Laptop Only)

Are you running your mainboard as a standalone device. Is standalone mode enabled in the BIOS?

• Yes
• No

Describe the bug

Laptop is connected to an external monitor via USB-C, powered via the same cable via PD.

dmesg shows

[    3.515902] ucsi_acpi USBC000:00: unknown error 256
[    3.984035] ucsi_acpi USBC000:00: unknown error 256
[    4.684068] ucsi_acpi USBC000:00: unknown error 256

Looks related to #3 but there is no CABLE-failed-related error messages, so it's better to open a new report.

The system seems unaffected and boots and works normally.

Steps To Reproduce

Steps to reproduce the behavior:

1. Boot the machine; the error seems to be always there

Expected behavior

There should be no errors in dmesg.

Operating System (please complete the following information):

• OS/Distribution: Ubuntu
• Version: 25.10
• Linux Kernel Version: Linux mavi-fw 6.17.0-14-generic #14-Ubuntu SMP PREEMPT_DYNAMIC Fri Jan 9 17:01:16 UTC 2026 x86_64 GNU/Linux

Additional context

Not sure whether the errors are always present or whether they're random.

[mvysny]

Rebooting with the USB-C/external-monitor/PD cable unplugged, the error is still present in dmesg:

[    3.602431] ucsi_acpi USBC000:00: unknown error 256
[    4.055215] ucsi_acpi USBC000:00: unknown error 256

[themkoi]

I have the same issue on the Framework Laptop 16 (AMD Ryzen™ 7040 Series) on bios 4.03 and kernel 6.19.4-2 during boot and when I reconnect the charger also randomly the charger stops charging for a second while also showing this error I dont know if the charging getting dropped is related to this error tho

[JohnAZoidberg]

This error message can be safely ignored, it is not related to charger not working.
It says 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.

This error is a good indication though for a plug/unplug event. If you see this when you are not plugging/unplugging anything that means something is going wrong with the PD negotiation.

Looks related to #3

Yes

when I reconnect the charger also randomly the charger stops charging for a second while also showing this error I dont know if the charging getting dropped is related to this error tho

For this it would be useful to have a separate issue. And you can please capture some EC logs using framework_tool --console follow when you are plugging in the charger.