u/mulantis

I have a new Dell XPS 13 DX13260. This is the 2026 model with the Intel Core 5 320 (Wildcat Lake). It has no Thunderbolt. I use Omarchy 4.0.0. The laptop is good, but USB-C docks do not operate correctly.

The problem

The two docks fail differently. Only the video output is correct on both.

Function	Cable Matters 201054	Satechi ST-TCMA2S
DisplayPort or HDMI video	Yes	Yes
USB 2.0 (keyboard, mouse, YubiKey)	No	Yes
Gigabit ethernet	No	No
SD card reader	No	No
SuperSpeed link	Trains at 10 Gbps, then drops in 20 to 50 seconds	Trains, then drops in less than 5 seconds

The Cable Matters dock fails on USB 2.0 and on USB 3. The Satechi dock fails only on USB 3. No dock gives me ethernet.

What the kernel log shows

My first theory was not correct. The SuperSpeed hubs do enumerate. Both docks made a link at 10 Gbps on this laptop, the ethernet included. But the links do not stay up.

Cable Matters 201054:

• The full SuperSpeed tree comes up: 0bda:0423, then 0411, then the RTL8153 ethernet.
• The ethernet interface gets a name and operates.
• After 20 to 50 seconds, the full tree disconnects with error -71.
• The USB 2.0 side of this dock is bad from the start. The kernel finds the hub at full-speed. Then it shows device descriptor read/64, error -71, then power cycles, then unable to enumerate.

Satechi ST-TCMA2S (captive cable):

• The SuperSpeed hub 2109:0817 enumerates, sometimes when DisplayPort is already up.
• It disconnects in less than 5 seconds.
• In one log, the kernel stops for 5.3 seconds. Then it shows xhci_hcd WARN Set TR Deq Ptr cmd failed. Then the hub disconnects.
• The ethernet and the card reader of this dock never enumerate.
• The USB 2.0 side is correct.

Two docks. Two different failures. One laptop.

Causes that I removed

• The laptop USB 3 path. A Ugreen NVMe enclosure (0bda:9210) stays at SuperSpeed Plus Gen 2x1 (10 Gbps) on both ports for many minutes.
• The dock hardware. Both docks operate fully on a Windows PC.
• The Cable Matters detachable cable. The same cable operates correctly on the Windows PC, at full speed. A USB 2.0 D+/D- pair that carries data on one host is not a bad pair. Thus the cable is not the cause.
• "DisplayPort takes all four lanes". This was my first theory. The logs do not agree with it. SuperSpeed makes a link when DisplayPort is up. This is pin assignment D, not C. Also, the problem occurs when no display is connected.
• The BIOS. Version 1.6.0, A06, dated 2026-07-16. This is the latest version. This SKU has no Thunderbolt, thus the setup has no Thunderbolt option.
• The kernel version. The behaviour is the same on 7.1.4 and 7.1.8.
• usbcore.autosuspend=-1**.** No change.
• intel_pmc_mux**.** The driver binds INTC105C. This ACPI ID is not on my machine. The mainline table stops at Lunar Lake, thus a newer kernel does not help.
• The Omarchy version. I went from 3.x to 4.0.0. There was no change. Omarchy is a userland layer, thus this result is as expected.
• The Cable Matters 4K/HD switch. Both positions give the same result.

An unusual firmware condition

UCSI reports number_of_alternate_modes = 0 for the port and for the partner. But the Billboard descriptor of the dock reports that DisplayPort alt-mode is configured: wSVID = 0xFF01, bmConfigured = 0b11. Also, data_role shows [device], but the laptop is the host. And the typec-to-usb port map is crossed. Thus I do not trust the UCSI data from this Dell firmware. As a result, typec_displayport does not bind, and there is no configuration file that can set the pin assignment.

My theory now

The cause is link stability, not lane allocation. And the cause is in the laptop.

Both cables are now removed as a cause. The Satechi cable is captive. The Cable Matters cable operates correctly on a Windows PC. Both docks also operate correctly on that PC. Thus only one item is common to the two failures: this laptop.

The primary suspect is the EC, PD or IOM firmware of the laptop, in the mixed DisplayPort and USB 3 mux state. The two failures have different shapes, but they start from the same point. PD negotiates. The link trains. Then the link fails in seconds.

Questions

1. Do you have a DX13260, or a different 2026 Wildcat Lake XPS, with a USB-C dock? Does your SuperSpeed link stay up?
2. Did you see number_of_alternate_modes = 0 on Dell UCSI firmware? Did a BIOS update correct it?
3. Do you know a dock that operates correctly with this laptop generation?

I did a search. All the "XPS 13 dock on Linux" topics are about the 9350, 9360 and 9380 Thunderbolt models. They do not apply. I found no public report for this SKU.