[vladvasiliu]

I think there are plenty of places that need to be up to spec and whose tolerances may add up.

I have a USB-C cable pretending to do 10 Gbps + 4K60 display port. I've used it to connect my HP laptops to my HP docking station. I have two similar laptops, 840 and 845 G8s, both with two USB-C ports each.

The 840 works as expected. The 845 only works if the cable is plugged in one specific way in one specific port. I now have a Lenovo laptop, also with two USB-C ports. I haven't tried DP-out with this computer, but Linux complains about there being issues when the dock is connected with this cable. On Windows, the whole USB stack sometimes goes foobar after a sleep/wake cycle. If, say, a mouse was initially connected, it'll keep working, but any new USB device won't, even the mouse if disconnected and reconnected. Shutting down Windows takes around 10 minutes and shows some driver issue at the end. Everything works after a reboot.

With a separate no-name docking station, everything works perfectly on the 845, but the 840 can't do 4k60 on it; it doesn't show up in the options. Haven't tried the Lenovo with this particular dock.

Both docks have DP alt mode, not DisplayLink or whatever other USB-attached GPU.