HB-U4HP on Dell Inspiron 16 Plus in Linux -- sometimes works, usually doesn't


  • Hey folks, I bought a HB-U4HP from Amazon a few months ago because my laptop (a Dell Inspiron 16 Plus 7640, with the discrete GPU) only has a single USB-C port and I need multiple external monitors and 2.5Gbit network.

    I'm running Fedora 40 with the most recent kernel 6.11.3 and at the moment, the dock isn't functional; I get this repeated in my dmesg every 2 seconds forever: 

    [  915.005213] thunderbolt 0-0:1.1: new retimer found, vendor=0x8087 device=0xd9c
    [  915.213065] thunderbolt 0-0:1.1: retimer disconnected
    [  916.534043] thunderbolt 0-0:1.1: new retimer found, vendor=0x8087 device=0xd9c
    [  916.749568] thunderbolt 0-0:1.1: retimer disconnected

    At various times in the recent past, the dock has worked OK, but not for the past few days. I just updated my laptop BIOS today, but that made no difference.

    Any tips? I'd rather not return this and get the official Dell dock, as it's quite expensive and very large. Thanks!



  • @Sabrent any ideas? :)


  • @alex Running this through a quick AI prompt, the suggestions are: update kernel/OS, update firmware for the Thunderbolt controller, ensure TB security settings (some may be in UEFI/BIOS) are less restrictive, check USB power management and disable autosuspend, ensure the Bolt service is running. Some kernel parameters for TB features can also be modified such as force_power. If there's a firmware update available for the hub, customer service will know/have this. Do try to use the hub on different ports and systems if possible to see if it's functional at all.


  • > If there's a firmware update available for the hub, customer service will know/have this

    @Sabrent is this you? Do you know/have this? 🤣


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