Trouble with USB-C to HDMI

BobDoolittle

4/14/24, 11:27 PM

I am trying to connect two external monitors to my laptop via a Selore&S-Global USB C to Dual HDMI Adapter.

It works reasonably well with Windows (after a couple of initial disconnect/reconnect events it becomes quite stable), so the hardware is compatible.

xrandr detects the monitors and they are visible in Settings.

Sometimes upon booting Ubuntu 22.04 the monitors are initially driven, but then start disconnecting and reconnecting and eventually go black. The laptop freezes intermittently during this period until the adapter is unplugged.

My laptop uses integrated Intel UHD Graphics 630 (Thunderbolt 3 USB 3.1 Gen 2) and also NVIDIA GeForce RTX 2070 Max-Q. I am plugging the adapter into the Thunderbolt USB-C port.

% sudo lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation CoffeeLake-H GT2 [UHD Graphics 630]
01:00.0 VGA compatible controller: NVIDIA Corporation TU106M [GeForce RTX 2070 Mobile] (rev a1)

I see this error repeating in dmesg output:

[ 1316.331073] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PCI0.GLAN.GPEH], AE_NOT_FOUND (20220331/psargs-330)

[ 1316.331112] No Local Variables are initialized for Method [_L6D]

[ 1316.331119] No Arguments are initialized for method [_L6D]

[ 1316.331128] ACPI Error: Aborting method \_GPE._L6D due to previous error (AE_NOT_FOUND) (20220331/psparse-529)
[ 1316.331157] ACPI Error: AE_NOT_FOUND, while evaluating GPE method [_L6D] (20220331/evgpe-511)
[ 1324.701972] usb 1-11: USB disconnect, device number 15
[ 1326.004425] usb 1-11: new full-speed USB device number 16 using xhci_hcd
[ 1326.165779] usb 1-11: not running at top speed; connect to a high speed hub
[ 1326.188456] usb 1-11: New USB device found, idVendor=2109, idProduct=0103, bcdDevice=15.51
[ 1326.188471] usb 1-11: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1326.188478] usb 1-11: Product: USB 2.0 BILLBOARD             
[ 1326.188483] usb 1-11: Manufacturer: VIA Technologies Inc.         
[ 1326.188488] usb 1-11: SerialNumber: 0000000000000001

and also lots of

[ 6178.052158] i915 0000:00:02.0: [drm] *ERROR* CPU pipe B FIFO underrun

A complete dmesg log is here.

Any suggestions on what might be going wrong?

172

0 + 3

displaylink

graphics

intel-graphics

thunderbolt

David

4/15/24, 7:27 AM

If it has to retry a few time in Windows I would say it does not work well in Windows either. To be clear this adapter splits the signal from one source to two monitors?

BobDoolittle

4/18/24, 3:56 AM

Yes it takes Thunderbolt USB-C and splits to two HDMI. While I agree it's not ideal on Windows either there's a big difference between an initial 2-3 second settling on Windows and never working at all on Linux (in fact freezing my system).

BobDoolittle

4/18/24, 3:58 AM

I would purchase another similar product if I knew of one which is known to work well with Linux.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Trouble with USB-C to HDMI

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