Meelis Roos wrote:
Is it something wrong with the device, Linux USB stack or UDL driver?
It looks like the device.
[379953.534772] usb 1-3.4: new high-speed USB device number 23 using xhci_hcd [379953.630502] usb 1-3.4: New USB device found, idVendor=17e9, idProduct=01e0, bcdDevice= 0.03 [379953.635493] usb 1-3.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [379953.640411] usb 1-3.4: Product: Lenovo Enhanced USB Port Replicator [379953.645573] usb 1-3.4: Manufacturer: DisplayLink [379953.650430] usb 1-3.4: SerialNumber: 01>0-128530 [379953.662128] [drm] vendor descriptor length:e0 data:00 00 00 00 00 00 00 00 00 00 00
Do the descriptors perhaps change, if you run lsusb -v for the device a second or two after plugging it in? (Of course they shouldn't, but ..)
Also, the device connects as a high-speed (480Mbps) device through xhci (so perhaps on a super-speed port?). Can you try connecting the device to a high-speed-only port and see if it behaves the same?
It might be enough to place a high-speed hub between computer and device for that test.
Or if you already tested with a high-speed-only port on your xHCI but the device is actually super-speed-capable then can you try connecting it to a super-speed port?
//Peter