USB-C DisplayPort output fails with NexDock 2 on devices with Intel 600 series graphics
I have a GPD Micro PC and a NexDock 2, and I'm trying to get them to work together on Linux. However, when I attempt to connect them via USB-C, the display on the Micro PC flashes about once a second, and I get no video output on the NexDock 2.
Tried with a kernel from drm-tip, that one actually shows some static during boot as well which the stock distro kernel does not (though it looks fine once I've gotten to SDDM). This kernel showed the same behavior when the NexDock was plugged in.
Kernel: 5.6.0+ (commit fa9f8453ffb88a4fc4e36d68b84a7ff9bf90f769 from drm-tip) Distribution: Ubuntu 19.10 Machine: GPD Micro PC Architecture: x86_64 Display connector: USB-C (using DisplayPort alt mode)
Steps to reproduce: Plug the Micro PC into the USB-C port of the NexDock 2 closest to the touchpad (it has several type-C ports, only this one is DisplayPort alt-mode).
Frequency: Always
Dmesg log is attached; I started from a fresh boot, logged in, then attached the NexDock 2. nexdock2.log