Hi Mathias, today I got access to another Dell Latitude model, which shows the exact same issue as the Latitude from before. This time it's a slightly older model with a 12th gen Intel CPU: [ 0.000000] DMI: Dell Inc. Latitude 5430/0260KT, BIOS 1.12.0 03/20/2023 [ 0.092576] smpboot: CPU0: 12th Gen Intel(R) Core(TM) i5-1245U (family: 0x6, model: 0x9a, stepping: 0x4) The issue is very easy to reproduce: just boot a recent Ubuntu 23.04 from an USB device, reboot, and the network interface on the dock is gone. Only re-plugging the dock's USB cable (or shutting down and restarting the system) helps to recover the net interface on the dock. I have three docks here (Dell WD19TB, Dell WD22TB4, Lenovo USB-C), all three show the same behaviour. Running the most recent linux kernel does not help. If I can provide any useful logs I'd be happy to help, just let me know. Thanks and best regards, Christian Am 01.06.23 um 15:54 schrieb Mathias Nyman: > On 31.5.2023 14.56, Christian Schaubschläger wrote: >> Hi, >> >>> Attached is a patch that adds more debugging, adds a minimum >>> "power on to power good" delay, (as hub reports 0ms), and checks port link >>> states during hub initialization. >>> >>> Does it help? Could you take logs with that patch applied. >>> >>> Only dmesg with xhci and usbcore dynamic debug are needed. >>> xhci traces won't help as issue seems to be between the hub inthe dock and the NIC >> patch applied, see logs in the attachment. The behaviour is unchanged. >> >> Thanks, >> Christian > Thanks, > > In the failed case the hub in the dock doesn't show any activity > on port4 where the NIC is connected. No changes, link isn't in any > error state. It looks just like any empty port. > > I don't have any idea what's going on. > > I guess it's not possible to connect a protocol analyzer between the > hub in the dock and the NIC? > > ok success case: > > [ 1.712754] usb 6-2-port1: status 02a0 change 0000 > [ 1.713070] usb 6-2-port2: status 02a0 change 0000 > [ 1.713567] usb 6-2-port3: status 0203 change 0010 <- another hub > [ 1.714184] usb 6-2-port4: status 0203 change 0010 <- NIC > > nok failed case: > > [ 1.716756] usb 6-2-port1: status 02a0 change 0000 > [ 1.717036] usb 6-2-port2: status 02a0 change 0000 > [ 1.717395] usb 6-2-port3: status 0203 change 0010 <- another hub > [ 1.717976] usb 6-2-port4: status 02a0 change 0000 > > Thanks > Mathias
