Sway nvidia flickering

1

I recently started using NixOS on a Lenovo X1 extreme laptop with an Intel and a Nvidia graphic card. Preferably I want to use Sway as tiling window manager. When I attach an external monitor with HDMI cable I experience flickering. It seems similar to what @nomadics describe here and is indeed very annoying.

As I am using Sway instead of Hyprland (both are built on Wayland) I decided to create a new topic instead of commenting on the topic linked above. However I suspect, these issues are related, and this could be an issue with the nvidia graphic card driver - but I am reaching the edge of my current knowledge here and will appreciate any further help.

Temporarily I have switched to Gnome that also runs on xorg. Here I do not experience any flickering on the external monitor.

Graphic card info:

$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation Alder Lake-P Integrated Graphics Controller (rev 0c)
01:00.0 VGA compatible controller: NVIDIA Corporation GA107M [GeForce RTX 3050 Ti Mobile] (rev a1)

$ lcpci | less
/VGA
00:02.0 VGA compatible controller: Intel Corporation Alder Lake-P Integrated Graphics Controller (rev 0c) (prog-if 00 [VGA controller])
        Subsystem: Lenovo Device 22f8
        Flags: bus master, fast devsel, latency 0, IRQ 189, IOMMU group 0
        Memory at 625b000000 (64-bit, non-prefetchable) [size=16M]
        Memory at 4000000000 (64-bit, prefetchable) [size=512M]
        I/O ports at 4000 [size=64]
        Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
        Capabilities: <access denied>
        Kernel driver in use: i915
        Kernel modules: i915
01:00.0 VGA compatible controller: NVIDIA Corporation GA107M [GeForce RTX 3050 Ti Mobile] (rev a1) (prog-if 00 [VGA controller])
        Subsystem: Lenovo Device 22f8
        Flags: bus master, fast devsel, latency 0, IRQ 190, IOMMU group 16
        Memory at b3000000 (32-bit, non-prefetchable) [size=16M]
        Memory at 6000000000 (64-bit, prefetchable) [size=8G]
        Memory at 6200000000 (64-bit, prefetchable) [size=32M]
        I/O ports at 3000 [size=128]
        Expansion ROM at b4080000 [virtual] [disabled] [size=512K]
        Capabilities: <access denied>
        Kernel driver in use: nvidia
        Kernel modules: nvidiafb, nouveau, nvidia_drm, nvidia

System info:

$ nix-info -m
 - system: `"x86_64-linux"`
 - host os: `Linux 6.1.39, NixOS, 23.11 (Tapir), 23.11.20230724.b12803b`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.15.1`
 - channels(root): `"nixos-23.05"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

Relevant snippets from configuration.nix regarding nvidia and sway installation:

  environment.loginShellInit = ''
    if [[ -z $DISPLAY ]] && [[ $(tty) = /dev/tty1 ]]; then
          sway --unsupported-gpu -V > .sway-log 2>&1
    fi
  '';

  nixpkgs.config.allowUnfree = true;

  hardware.nvidia = {
    package = config.boot.kernelPackages.nvidiaPackages.stable;
    nvidiaPersistenced = true;
    modesetting.enable = true;
    prime = {
      sync.enable = true;
      nvidiaBusId = "PCI:1:0:0";
      intelBusId = "PCI:0:2:0";
    };
  };

  services.xserver = {
    enable = true;
    videoDrivers = [
      "nvidia"
    ];
  };

  programs.sway = {
    enable = true;
    wrapperFeatures.gtk = true;
    extraPackages = with pkgs; [
      linux-firmware
      swaylock
      swayidle
      alacritty
      i3status-rust
      brightnessctl
      wayland
    ];
    extraSessionCommands = ''
      export MOZ_ENABLE_WAYLAND=1
      export WLR_DRM_NO_MODIFIERS=1
      export WLR_DRM_DEVICES=/dev/dri/card0
    '';
  };
2

Wlroots does not support the nvidia drivers (nor does sway for that matter). The hyprland wiki has some notes on potential fixes, it may involve patching wlroots: Nvidia | Hyprland Wiki

YMMV, given you’re using a different compositor altogether.

1 Like
3

Yes, I did try to patch wlroots as well, however it did not help. The flickering continues.

The patch I tried out was this, which is the same patch as suggested in method 1 , for fixing random flickering in the link you suggested

4

I fixed the flickering on sway + nvidia via export WLR_RENDERER=vulkan and

  hardware.opengl.extraPackages = with pkgs; [
    # trying to fix `WLR_RENDERER=vulkan sway`
    vulkan-validation-layers 
  ];
2 Likes
5

Hmm, thanks for the suggestion. I have tried it out and here is what I found:

External monitor gets inactive (before DP-7 ‘Samsung’ was in the active state). Flickering continues - however this time the flickering is on the inbuilt monitor eDP-1.

output from $ swaymsg -t get_outputs:

Output eDP-1 'BOE 0x0AE0 Unknown' (focused)

(...)

Output DP-7 'Samsung Electric Company LC49G95T H1AK500000' (inactive)

I am happy to hear the vulkan trick , helped in your case. Unfortunately it did not work on my hardware

6

The new nvidia driver has some fixes that might be of interest to you: Linux x64 (AMD64/EM64T) Display Driver | 535.98 | Linux 64-bit | NVIDIA

7

Wow - thanks for the tip, I will try it out and let you know how it worked.

Indeed sounds promising

8

@eska did you have any luck with this? Same symptoms here, down to enabling the vulkan backend disabling the external monitor and making the internal one start flickering instead.

9

I am having the same problem. Have you found a solution?

10

Hi all,

Unfortunately i did not find a solution - yet.

I have switched to using only external monitor and the flickering issue persist when using sway.

Currently thinking to adopt i3 in my work flow, but it seems a little like moving back instead of moving forward?

Any help with this is much welcome!

11

yes exactly - I get same behaviour with the vulkan backend:(

I am still working to get sway working with external monitor, soon I will get new hardware with single graphic card instead of dual, which will simplify setup, and I will give it another go trying to fix this issue:)

12

Looks like that’s a high refresh monitor with g-sync. Nvidia is known to have issues with that even to this day, especially on super high refresh rate monitors like this one.

The first step to getting a flicker-free experience with nvidia is to get explicit sync support anyway, though. This thread covers the latest state pretty well: Screen Flickering and Tearing with NixOS + Sway + NVIDIA - #8 by ProfDoof

tl;dr is that there finally is a way, but you currently need to use pre-release versions of wlroots and sway (hyprland does not and will never support this as long as it’s a wlroots compositor), in addition to the most newestest nvidia driver, neither of which is available on stable NixOS, so you’ll have to do some work.

Even then, VRR and refresh rates north of 144 still often cause problems, you’ll probably want to create a separate thread if it still doesn’t work after setting up explicit sync.