udl: Unrecognized vendor firmware descriptor (all zeroes)

[Peter Stuge]

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