Support for LG Ultrafine 5K monitor

Did anyone try this? I would like to use 2x LG Ultrafine 4K with the Framework, if I buy one.

My experience with recently purchase LG 38WN95C-W monitor. The LG supplied Thunderbolt 3 Cable did not work with the Framework Laptop. I purchased a Cable Matters 40Gbps USB4 Thunderbolt 4 Cable and it successfully connected at 3840x1600@120Hz. I am using SwayWM on Arch Linux.

1 Like

EDIT: The LG UltraFine 5K works perfectly under Windows 10 at full resolution stably and with no tearing issues. This tells me the Framework firmware is fine as of now. I’m using the Apple’s 0.8m Thunderbolt Cable.


On Linux, I can confirm that it works great using Apple’s 0.8m Thunderbolt Cable. Longer cables, including the supplied cable with the monitor, did not work. This seems to be a firmware issue with a fix in the pipeline.

EDIT: I’ve found that on Wayland on Linux, there is screen tearing vertically in the middle when scrolling and moving content. In addition, night light only applies to half of the screen. There is an open issue on mutter and a in-progress merge request to fix it.

EDIT: Not so great on Linux with Wayland. Occasionally, the second display port stream stops working and it takes a mix of reconnecting and power cycling the screen to make it work again.

EDIT: Tracking the issue on drm/intel bug tracker.

4 Likes

Without that TB4 certification for the Framework laptop, anything that uses TB connectivity is a YMMV IMO…because as nrp mentioned, they (the certification body) still need to come up with /develop the test cases. Without the certification, there’s less assurance as to whether TB is functioning correctly on the Framework laptop…or if any TB connectivity issue is caused by some other factors.

Reference: the later part of this post…

1 Like

I actually tested this with Windows and it works perfect, so it must be some Linux/Wayland specific issue I’m having.

2 Likes

Hi all,

I have the Lg40 Ultra wide but I have issues connecting VIA usb C on W11. All drivers from both windows and LG are updated, also FW drivers. Been searching for an answer/solution for 3 days. Has anyone found a solution or the pair can only work over DP and HDMI?

Here a link to a video of my issue.

Thanks in advance if someone has a solution!

Looks like most people here haven’t actually tried and reported their success/failure with LG Ultrafine 5k.

I’m using Arch with Sway/Wayland,

When I first connected the LG Ultrafine 5k to my usb-c port the framework display would shut off for a few seconds and then come back on, and this would repeat over and over again.

From the dmesg output this is what I was seeing over and over again (this is just a short snippet of a larger dmesg output):

[148123.707088] thunderbolt 1-0:3.1: retimer disconnected
[148123.719290] thunderbolt 1-3: device disconnected
[148127.598434] thunderbolt 1-0:3.1: new retimer found, vendor=0x8087 device=0x15ee
[148128.250885] thunderbolt 1-3: new device found, vendor=0x1e device=0x1114
[148128.250895] thunderbolt 1-3: LG Electronics UltraFine 5K
[148132.968013] thunderbolt 1-0:3.1: retimer disconnected
[148132.980416] thunderbolt 1-3: device disconnected
[148133.145343] usb 3-5: new high-speed USB device number 79 using xhci_hcd
[148136.789518] thunderbolt 1-0:3.1: new retimer found, vendor=0x8087 device=0x15ee
[148137.441204] thunderbolt 1-3: new device found, vendor=0x1e device=0x1114
[148137.441214] thunderbolt 1-3: LG Electronics UltraFine 5K
[148334.831281] thunderbolt 1-0:3.1: retimer disconnected
[148334.843710] thunderbolt 1-3: device disconnected
[148335.058661] usb 3-5: new high-speed USB device number 81 using xhci_hcd
[148336.078705] usb 3-5: device descriptor read/64, error -71
[148338.658017] thunderbolt 1-0:3.1: new retimer found, vendor=0x8087 device=0x15ee
[148339.312318] thunderbolt 1-3: new device found, vendor=0x1e device=0x1114
[148339.312330] thunderbolt 1-3: LG Electronics UltraFine 5K
[148341.130224] thunderbolt 1-0:3.1: retimer disconnected
[148341.140728] thunderbolt 1-3: device disconnected
[148342.548589] usb 3-5: new high-speed USB device number 83 using xhci_hcd

Note the thunderbolt connects and disconnects. The USB side of things fails to read the device descriptor with error -71. I did a cursory look into the Linux kernel USB drivers to see what was going on, but got lost and couldn’t find these error strings whatsoever.

Anyway the primary monitor kept shutting off every few seconds, presumably to do with those thunderbolt events in dmesg. I did manage to get output to the LG when I was just in VGA console mode, but it didn’t really work all that well (it was a mirrored display) as the LG display was really enlarged and nothing fit on the screen.

So after about 20 minutes of the annoying display cycling I unplugged the display.

My system is usually on hibernate, and when I did the above experiment it was resumed from a previous hibernate. Someone suggested I try with a reboot.

So I reboot and connected the display a second time.

The second time, nothing happened, no display power cycling. I checked dmesg and got the following messages:

[  152.656573] usb 3-4: new high-speed USB device number 76 using xhci_hcd
[  153.733249] usb 3-4: new high-speed USB device number 77 using xhci_hcd
[  155.029908] usb 3-4: new high-speed USB device number 78 using xhci_hcd
[  157.126575] usb 3-4: new high-speed USB device number 80 using xhci_hcd
[  160.046578] usb 3-4: new high-speed USB device number 81 using xhci_hcd
[  162.423321] usb 3-4: new high-speed USB device number 82 using xhci_hcd
[  163.466663] usb 3-4: new high-speed USB device number 83 using xhci_hcd
[  165.369892] usb 3-4: new high-speed USB device number 84 using xhci_hcd
[  166.389962] usb 3-4: device descriptor read/64, error -71
[  168.609913] usb 3-4: new high-speed USB device number 85 using xhci_hcd
[  169.693206] usb 3-4: new high-speed USB device number 86 using xhci_hcd
[  172.619953] usb 3-4: new high-speed USB device number 87 using xhci_hcd
[  173.663290] usb 3-4: new high-speed USB device number 88 using xhci_hcd
[  174.679955] usb 3-4: device descriptor read/64, error -71
[  178.713167] usb 3-4: new high-speed USB device number 89 using xhci_hcd
[  181.636646] usb 3-4: new high-speed USB device number 90 using xhci_hcd
[  182.686624] usb 3-4: new high-speed USB device number 91 using xhci_hcd
[  183.730014] usb 3-4: new high-speed USB device number 92 using xhci_hcd

No thunderbolt diagnostics. So for some reason the thunderbolt wasn’t being detected or not running.

I don’t know what else to do, so I’m seeking support.

I know the LG Ultrafine 5k can work in Linux because this reddit thread shows the poster having it working.

Edit: looks like I needed to charge my battery back up to high levels for the thunderbolt devices to be detected, which is strange because the LG should be doing power delivery.

I filed this exact bug back in June and linked it earlier in the thread: https://gitlab.freedesktop.org/drm/intel/-/issues/6265

Also, do you have a 11th Gen or a 12th Gen board?

1 Like

Sorry for delay in reply (for some reason I don’t get emails when this thread is updated). I have a 12th gen board.

I’ll add to your issue once my gitlab account is approved. Updated your bug report.

I notice you actually have the monitor working and displaying things. I haven’t even gotten that far. Am I missing something in userspace to work with the i915?

I have the same problem as “software_developer”. Also fan goes on high, once you start a few apps on 5k.

Can confirm, video, audio, camera all work on the 11th Generation Framework running Kubuntu (Linux) 22.04 using this cable

1 Like

Can you tell us which other cables you’ve tried that didn’t work? I have tried everything from Apple’s $200 pro cable, to all the other TB4 certified ones, short and long, and none works.

I’m suspecting that it’s Ubuntu that’s doing something different (or Xorg vs Wayland) since all those cables work wonderfully under Windows on the same machine.

Not anymore! It used to work initially, but now, blank screen and lots of errors in dmesg. I upgraded my board to 12th gen. No difference on the 5K display. However, my LG 4K display no longer loses connection if I plug in/out the power next to it. That’s an improvement!

I just used the one recommended above from the previous poster and linked in my post. I didn’t really try any other cables because that one “just worked”.

I just downloaded the Kubuntu and Ubuntu images and neither works with the monitor, using 3 different cables. Something fishy going on here.

I have the USB C adapters on the right side (power button side) of the laptop, the monitor is plugged into the one closest to the touch pad. I’m typing this on that setup now.

Do you mind pasting your dmesg log here?

This is me unplugging and plugging it back in

[ 6949.167672] pcieport 0000:00:07.1: pciehp: Slot(0-1): Link Down
[ 6949.167713] pcieport 0000:00:07.1: pciehp: Slot(0-1): Card not present
[ 6949.167808] xhci_hcd 0000:2e:00.0: remove, state 4
[ 6949.167862] usb usb6: USB disconnect, device number 1
[ 6949.167891] usb 6-1: USB disconnect, device number 2
[ 6949.167916] usb 6-1.1: USB disconnect, device number 5
[ 6949.219909] usb 6-1.4: USB disconnect, device number 3
[ 6949.219920] usb 6-1.4.3: USB disconnect, device number 4
[ 6949.332645] xhci_hcd 0000:2e:00.0: USB bus 6 deregistered
[ 6949.332726] xhci_hcd 0000:2e:00.0: xHCI host controller not responding, assume dead
[ 6949.332749] xhci_hcd 0000:2e:00.0: remove, state 1
[ 6949.332760] usb usb5: USB disconnect, device number 1
[ 6949.332764] usb 5-2: USB disconnect, device number 2
[ 6949.332768] usb 5-2.4: USB disconnect, device number 3
[ 6949.332772] usb 5-2.4.1: USB disconnect, device number 4
[ 6949.363189] usb 5-2.4.2: USB disconnect, device number 5
[ 6949.603631] xhci_hcd 0000:2e:00.0: Host halt failed, -19
[ 6949.603643] xhci_hcd 0000:2e:00.0: Host not accessible, reset failed.
[ 6949.606938] xhci_hcd 0000:2e:00.0: USB bus 5 deregistered
[ 6949.638811] pci 0000:2e:00.0: Removing from iommu group 20
[ 6949.642273] pci_bus 0000:2e: busn_res: [bus 2e] is released
[ 6949.670710] pci 0000:2d:02.0: Removing from iommu group 19
[ 6949.671827] pci_bus 0000:2d: busn_res: [bus 2d-2e] is released
[ 6949.702500] pci 0000:2c:00.0: Removing from iommu group 18
[ 6962.176181] pcieport 0000:00:07.1: pciehp: Slot(0-1): Card present
[ 6962.176187] pcieport 0000:00:07.1: pciehp: Slot(0-1): Link Up
[ 6962.314145] pci 0000:2c:00.0: [8086:15ef] type 01 class 0x060400
[ 6962.314233] pci 0000:2c:00.0: enabling Extended Tags
[ 6962.314453] pci 0000:2c:00.0: supports D1 D2
[ 6962.314456] pci 0000:2c:00.0: PME# supported from D0 D1 D2 D3hot D3cold
[ 6962.314644] pci 0000:2c:00.0: 8.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s PCIe x4 link at 0000:00:07.1 (capable of 31.504 Gb/s with 8.0 GT/s PCIe x4 link)
[ 6962.314901] pci 0000:2c:00.0: Adding to iommu group 18
[ 6962.315046] pcieport 0000:00:07.1: ASPM: current common clock configuration is inconsistent, reconfiguring
[ 6962.326205] pci 0000:2c:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[ 6962.326431] pci 0000:2d:02.0: [8086:15ef] type 01 class 0x060400
[ 6962.326517] pci 0000:2d:02.0: enabling Extended Tags
[ 6962.326725] pci 0000:2d:02.0: supports D1 D2
[ 6962.326728] pci 0000:2d:02.0: PME# supported from D0 D1 D2 D3hot D3cold
[ 6962.327079] pci 0000:2d:02.0: Adding to iommu group 19
[ 6962.327276] pci 0000:2c:00.0: PCI bridge to [bus 2d-55]
[ 6962.327288] pci 0000:2c:00.0: bridge window [io 0x0000-0x0fff]
[ 6962.327295] pci 0000:2c:00.0: bridge window [mem 0x00000000-0x000fffff]
[ 6962.327306] pci 0000:2c:00.0: bridge window [mem 0x00000000-0x000fffff 64bit pref]
[ 6962.327311] pci 0000:2d:02.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[ 6962.327511] pci 0000:2e:00.0: [8086:15f0] type 00 class 0x0c0330
[ 6962.327543] pci 0000:2e:00.0: reg 0x10: [mem 0x00000000-0x0000ffff]
[ 6962.327634] pci 0000:2e:00.0: enabling Extended Tags
[ 6962.327842] pci 0000:2e:00.0: supports D1 D2
[ 6962.327844] pci 0000:2e:00.0: PME# supported from D0 D1 D2 D3hot D3cold
[ 6962.327989] pci 0000:2e:00.0: 8.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s PCIe x4 link at 0000:00:07.1 (capable of 31.504 Gb/s with 8.0 GT/s PCIe x4 link)
[ 6962.328208] pci 0000:2e:00.0: Adding to iommu group 20
[ 6962.328385] pci 0000:2d:02.0: PCI bridge to [bus 2e-55]
[ 6962.328397] pci 0000:2d:02.0: bridge window [io 0x0000-0x0fff]
[ 6962.328403] pci 0000:2d:02.0: bridge window [mem 0x00000000-0x000fffff]
[ 6962.328414] pci 0000:2d:02.0: bridge window [mem 0x00000000-0x000fffff 64bit pref]
[ 6962.328418] pci_bus 0000:2e: busn_res: [bus 2e-55] end is updated to 2e
[ 6962.328426] pci_bus 0000:2d: busn_res: [bus 2d-55] end is updated to 2e
[ 6962.328442] pci 0000:2c:00.0: BAR 14: assigned [mem 0x6e000000-0x7a1fffff]
[ 6962.328446] pci 0000:2c:00.0: BAR 15: assigned [mem 0x6020000000-0x603bffffff 64bit pref]
[ 6962.328450] pci 0000:2c:00.0: BAR 13: assigned [io 0x5000-0x5fff]
[ 6962.328454] pci 0000:2d:02.0: BAR 14: assigned [mem 0x6e000000-0x7a1fffff]
[ 6962.328457] pci 0000:2d:02.0: BAR 15: assigned [mem 0x6020000000-0x603bffffff 64bit pref]
[ 6962.328460] pci 0000:2d:02.0: BAR 13: assigned [io 0x5000-0x5fff]
[ 6962.328464] pci 0000:2e:00.0: BAR 0: assigned [mem 0x6e000000-0x6e00ffff]
[ 6962.328473] pci 0000:2d:02.0: PCI bridge to [bus 2e]
[ 6962.328477] pci 0000:2d:02.0: bridge window [io 0x5000-0x5fff]
[ 6962.328486] pci 0000:2d:02.0: bridge window [mem 0x6e000000-0x7a1fffff]
[ 6962.328492] pci 0000:2d:02.0: bridge window [mem 0x6020000000-0x603bffffff 64bit pref]
[ 6962.328503] pci 0000:2c:00.0: PCI bridge to [bus 2d-2e]
[ 6962.328508] pci 0000:2c:00.0: bridge window [io 0x5000-0x5fff]
[ 6962.328516] pci 0000:2c:00.0: bridge window [mem 0x6e000000-0x7a1fffff]
[ 6962.328522] pci 0000:2c:00.0: bridge window [mem 0x6020000000-0x603bffffff 64bit pref]
[ 6962.328533] pcieport 0000:00:07.1: PCI bridge to [bus 2c-55]
[ 6962.328536] pcieport 0000:00:07.1: bridge window [io 0x5000-0x5fff]
[ 6962.328541] pcieport 0000:00:07.1: bridge window [mem 0x6e000000-0x7a1fffff]
[ 6962.328546] pcieport 0000:00:07.1: bridge window [mem 0x6020000000-0x603bffffff 64bit pref]
[ 6962.328602] pcieport 0000:2c:00.0: enabling device (0000 → 0003)
[ 6962.329070] pcieport 0000:2d:02.0: enabling device (0000 → 0003)
[ 6962.330133] pci 0000:2e:00.0: enabling device (0000 → 0002)
[ 6962.330940] xhci_hcd 0000:2e:00.0: xHCI Host Controller
[ 6962.330976] xhci_hcd 0000:2e:00.0: new USB bus registered, assigned bus number 5
[ 6962.332372] xhci_hcd 0000:2e:00.0: hcc params 0x200077c1 hci version 0x110 quirks 0x0000000200009810
[ 6962.333096] xhci_hcd 0000:2e:00.0: xHCI Host Controller
[ 6962.333105] xhci_hcd 0000:2e:00.0: new USB bus registered, assigned bus number 6
[ 6962.333113] xhci_hcd 0000:2e:00.0: Host supports USB 3.1 Enhanced SuperSpeed
[ 6962.333205] usb usb5: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 5.19
[ 6962.333213] usb usb5: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 6962.333218] usb usb5: Product: xHCI Host Controller
[ 6962.333222] usb usb5: Manufacturer: Linux 5.19.0-26-generic xhci-hcd
[ 6962.333226] usb usb5: SerialNumber: 0000:2e:00.0
[ 6962.333618] hub 5-0:1.0: USB hub found
[ 6962.333637] hub 5-0:1.0: 2 ports detected
[ 6962.333889] usb usb6: New USB device found, idVendor=1d6b, idProduct=0003, bcdDevice= 5.19
[ 6962.333894] usb usb6: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 6962.333897] usb usb6: Product: xHCI Host Controller
[ 6962.333899] usb usb6: Manufacturer: Linux 5.19.0-26-generic xhci-hcd
[ 6962.333901] usb usb6: SerialNumber: 0000:2e:00.0
[ 6962.334376] hub 6-0:1.0: USB hub found
[ 6962.334389] hub 6-0:1.0: 2 ports detected
[ 6962.590052] usb 5-2: new high-speed USB device number 2 using xhci_hcd
[ 6962.749246] usb 5-2: New USB device found, idVendor=043e, idProduct=9a61, bcdDevice=52.50
[ 6962.749255] usb 5-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 6962.749258] usb 5-2: Product: USB2.1 Hub
[ 6962.749261] usb 5-2: Manufacturer: LG Electronics Inc.
[ 6962.750721] hub 5-2:1.0: USB hub found
[ 6962.753838] hub 5-2:1.0: 4 ports detected
[ 6962.878302] usb 6-1: new SuperSpeed USB device number 2 using xhci_hcd
[ 6962.901965] usb 6-1: New USB device found, idVendor=043e, idProduct=9a60, bcdDevice=52.50
[ 6962.902002] usb 6-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 6962.902045] usb 6-1: Product: USB3.1 Hub
[ 6962.902049] usb 6-1: Manufacturer: LG Electronics Inc.
[ 6962.904894] hub 6-1:1.0: USB hub found
[ 6962.905262] hub 6-1:1.0: 4 ports detected
[ 6963.070049] usb 5-2.4: new high-speed USB device number 3 using xhci_hcd
[ 6963.194751] usb 5-2.4: New USB device found, idVendor=043e, idProduct=9a73, bcdDevice= 1.00
[ 6963.194761] usb 5-2.4: New USB device strings: Mfr=0, Product=0, SerialNumber=1
[ 6963.194764] usb 5-2.4: SerialNumber: 98000089ABD1
[ 6963.196155] hub 5-2.4:1.0: USB hub found
[ 6963.196205] hub 5-2.4:1.0: 3 ports detected
[ 6963.278231] usb 6-1.4: new SuperSpeed USB device number 3 using xhci_hcd
[ 6963.298728] usb 6-1.4: New USB device found, idVendor=043e, idProduct=9a71, bcdDevice= 1.00
[ 6963.298744] usb 6-1.4: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[ 6963.302163] hub 6-1.4:1.0: USB hub found
[ 6963.302293] hub 6-1.4:1.0: 3 ports detected
[ 6963.486059] usb 5-2.4.1: new high-speed USB device number 4 using xhci_hcd
[ 6963.606287] usb 5-2.4.1: New USB device found, idVendor=043e, idProduct=9a66, bcdDevice= 0.03
[ 6963.606297] usb 5-2.4.1: New USB device strings: Mfr=3, Product=1, SerialNumber=0
[ 6963.606300] usb 5-2.4.1: Product: LG UltraFine Display Audio
[ 6963.606303] usb 5-2.4.1: Manufacturer: LG Electronics Inc.
[ 6964.514191] usb 6-1.4.3: new SuperSpeed USB device number 4 using xhci_hcd
[ 6964.534843] usb 6-1.4.3: LPM exit latency is zeroed, disabling LPM.
[ 6964.535588] usb 6-1.4.3: New USB device found, idVendor=043e, idProduct=9a68, bcdDevice= 2.23
[ 6964.535596] usb 6-1.4.3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 6964.535600] usb 6-1.4.3: Product: LG UltraFine Display Camera
[ 6964.535603] usb 6-1.4.3: Manufacturer: LG Electronlcs Inc.
[ 6964.539028] usb 6-1.4.3: Found UVC 1.10 device LG UltraFine Display Camera (043e:9a68)
[ 6964.550002] input: LG UltraFine Display Camera as /devices/pci0000:00/0000:00:07.1/0000:2c:00.0/0000:2d:02.0/0000:2e:00.0/usb6/6-1/6-1.4/6-1.4.3/6-1.4.3:1.0/input/input48
[ 6964.553203] hid-generic 0003:043E:9A68.0022: hiddev2,hidraw9: USB HID v1.01 Device [LG Electronlcs Inc. LG UltraFine Display Camera] on usb-0000:2e:00.0-1.4.3/input2
[ 6966.662111] usb 5-2.4.2: new full-speed USB device number 5 using xhci_hcd
[ 6966.768248] usb 5-2.4.2: New USB device found, idVendor=043e, idProduct=9a70, bcdDevice= 4.13
[ 6966.768263] usb 5-2.4.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 6966.768268] usb 5-2.4.2: Product: LG UltraFine Display Controls
[ 6966.768272] usb 5-2.4.2: Manufacturer: LG Electronics Inc.
[ 6966.787158] hid-generic 0003:043E:9A70.0023: hiddev3,hidraw10: USB HID v1.11 Device [LG Electronics Inc. LG UltraFine Display Controls] on usb-0000:2e:00.0-2.4.2/input0
[ 6966.788292] hid-generic 0003:043E:9A70.0024: hiddev4,hidraw11: USB HID v1.11 Device [LG Electronics Inc. LG UltraFine Display Controls] on usb-0000:2e:00.0-2.4.2/input1
[ 6966.789649] hid-generic 0003:043E:9A70.0025: hiddev5,hidraw12: USB HID v1.11 Device [LG Electronics Inc. LG UltraFine Display Controls] on usb-0000:2e:00.0-2.4.2/input2
[ 6968.430311] usb 6-1.1: new SuperSpeed USB device number 5 using xhci_hcd
[ 6968.454538] usb 6-1.1: LPM exit latency is zeroed, disabling LPM.
[ 6968.454812] usb 6-1.1: config 1 interface 2 altsetting 0 endpoint 0x89 has an invalid bInterval 81, changing to 10
[ 6968.455201] usb 6-1.1: New USB device found, idVendor=0fd9, idProduct=0078, bcdDevice= 1.00
[ 6968.455205] usb 6-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=11
[ 6968.455208] usb 6-1.1: Product: Elgato Facecam
[ 6968.455211] usb 6-1.1: Manufacturer: Elgato
[ 6968.455213] usb 6-1.1: SerialNumber: FW52K1A13393
[ 6968.459409] usb 6-1.1: Found UVC 1.10 device Elgato Facecam (0fd9:0078)
[ 6968.544024] input: Elgato Facecam: Elgato Facecam as /devices/pci0000:00/0000:00:07.1/0000:2c:00.0/0000:2d:02.0/0000:2e:00.0/usb6/6-1/6-1.1/6-1.1:1.0/input/input49
[ 6968.547456] hid-generic 0003:0FD9:0078.0026: hiddev6,hidraw13: USB HID v1.01 Device [Elgato Elgato Facecam] on usb-0000:2e:00.0-1.1/input2

There is no mention of LG UltraFine 5K (note the 5K) anywhere in your logs! Are you sure that’s what you screen is. There isn’t any thunderbolt lines in there either.

Specifically, I’m looking for this line:

[ 1111.860826] thunderbolt 0-3: new device found, vendor=0x1e device=0x1114
[ 1111.860838] thunderbolt 0-3: LG Electronics UltraFine 5K

I have that in my logs as does @software_developer

If I disconnect my Linux laptop and connect the Mac, this is what it tells me so ¯_(ツ)_/¯ you tell me:

LG UltraFine:
          Resolution: 5120 x 2880 (5K/UHD+ - Ultra High Definition Plus)
          UI Looks like: 2560 x 1440
          Framebuffer Depth: 30-Bit Color (ARGB2101010)
          Main Display: Yes
          Mirror: Off
          Online: Yes
          Rotation: Supported
          Automatically Adjust Brightness: Yes