I use a Thinkpad P1 GEN2 (2019, 20QT000RGE) , with NVIDIA Quadro T1000 and a Think Pad Thunderbolt 3 Workstation Dock (40AN0230WW, mind it is the 'Workstation' Dock), on which I attach one or two external 4K-Monitors by either Display Port or HDMI.
This works fine with Windows 10, but with Linux I could not find a stable configuration where the screen does not gets black.
Has anybody this or a similar hardware-configuration running with Linux, and if yes, what is your software setup and configuration?
Any ideas what could be wrong or how to get closer to the issue?
I give details below:
It happened rarley that the external monitor was shown, but after power-cycling it always stayed black and that is not reproducible. I never made it to show 2 monitors.
The external monitor is reported correctly to the operation system, likewise xrandr shows all information about the monitor correctly. One can configure the screens (resolution, multi-head with ...), one can move with the mouse (or move windows) to it and back and I could not find any error messages within Xorg.*.log . From the operating system perspective, everything looks perfect, just the screen stays black. I appears as if the monitor would be in powersave, but I even turned that of (in the Monitor, also by xset), and it happens with different monitors (different brands). When hot-plugging a monitor to the dock, usually the system load increases for a while (a minute) during which the system is extremly slow (mouse hard to move) and the 'top' command tells that nvidia-modeset is consuming ~90% of the CPU.
I tried different things, without success:
- I use Ubuntu 18.04.03 , also tried 19.10, Mint 19.2.
- On Ubuntu 18.04 I tried with (standard) gdm (Gnome, no Wayland) , also I tried with Unity (since some report that gdm is an issue).
- I used different kernels, up to 5.3.11.
- I did a BIOS update on the Laptop to the (by now current) BIOS version 1.27
- I use nvidia-driver-435 (by now most current for that hardware), also tried the nvidia-driver-440.
- For this dock (a 'Worksation' Dock), there is apparently no firmware update so far (just for the older ones). I just checked again there: https://pcsupport.lenovo.com/fi/en/products/accessory/docks/thunderbolt-3-workstation-dock/downloads/driver-list/ . There is just the update tool, which I did run (with Windows 10), but it says no updated available to me.
- It happens both with discrete graphics and hybrid graphics within the BIOS, so it seems not to be one of the Bumblebee/Prime issues which are widly discussed in this forum (which are about switching to hybrid), while I don't say it has nothing to do with Optimus. Anyway, the command 'prime-select query' outputs 'nvidia'.
- Using the HDMI-output directly on the Laptop, without the docking station sometimes works, but is not very stable, and sometimes it is black as well, also I'd like to use 2 Monitors.
- It makes no difference whether on the docking station the display port or the HDMI output is used.
- It makes no difference whether screens are extended or mirrored, the external is (almost) always black, and the internal (laptop) always shows a picture.
- Just to prevent questions: I attached the required two power supplies to the dock (attached are 230 W and 135W both at once).
- Everything else in the Dock (USB, Ethernet) seems to work.
- Everything else with the Thinkpad P1 works great with Ubuntu 18.04, but not having an external screen is a blocker.
- Two collegues of mine got a similar issue with exactly the same hardware and also Ubuntu 18.04: they do see some output, but a rectangular parts of the screen is scrambled with gray noise.
And a hint: The hardware is said to have the external output by thunderbolt wired to the nvidia chip, but I can not prove that, it is just something what I read several times somewhere.