Unverified Commit 9ba1b4e7 authored by Martin Weinelt's avatar Martin Weinelt Committed by GitHub
Browse files

nixos/ipu6, nixos/v4l2-relayd: fix device visibility, relay stability, and...

nixos/ipu6, nixos/v4l2-relayd: fix device visibility, relay stability, and PipeWire integration (#511061)
parents 3866f0db 6fa956a7
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+54 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ let
  inherit (lib)
    mkDefault
    mkEnableOption
    mkForce
    mkIf
    mkOption
    optional
@@ -38,6 +39,19 @@ in
      '';
    };

    videoDeviceNumber = mkOption {
      type = types.int;
      default = 50;
      description = ''
        v4l2loopback device number for the relay output (`/dev/videoN`).

        Must be fixed so application camera permission grants, which are keyed to
        the PipeWire node name (derived from the sysfs device path), survive
        reboots. Choose a number above the IPU6 raw node range (typically 3-34)
        and any other v4l2loopback devices on the system.
      '';
    };

  };

  config = mkIf cfg.enable {
@@ -51,10 +65,32 @@ in
      ivsc-firmware
    ];

    # Restrict IPU6 raw nodes and media controller to root. DRIVERS== matches the
    # parent PCI device. TAG-="uaccess" blocks logind ACL grants at login.
    services.udev.extraRules = ''
      SUBSYSTEM=="intel-ipu6-psys", MODE="0660", GROUP="video"
      SUBSYSTEM=="media", DRIVERS=="intel-ipu6", MODE="0600", GROUP="root", TAG-="uaccess"
      SUBSYSTEM=="video4linux", DRIVERS=="intel-ipu6", MODE="0600", GROUP="root", TAG-="uaccess"
    '';

    # ipu6-camera-hal writes AIQ tuning data and debug logs here.
    systemd.tmpfiles.rules = [ "d /run/camera 0755 root video -" ];

    # Disable raw IPU6 nodes in WirePlumber. Matched via udev ID_V4L_PRODUCT=ipu6,
    # set by the kernel at device registration without requiring a device open.
    services.pipewire.wireplumber.extraConfig."ipu6-v4l2-rules" = {
      "monitor.v4l2.rules" = [
        {
          matches = [ { "device.product.name" = "ipu6"; } ];
          actions = {
            "update-props" = {
              "device.disabled" = true;
            };
          };
        }
      ];
    };

    services.v4l2-relayd.instances.ipu6 = {
      enable = mkDefault true;

@@ -72,5 +108,23 @@ in
        format = mkIf (cfg.platform != "ipu6") (mkDefault "NV12");
      };
    };

    # Override preStart/postStop from the v4l2-relayd module:
    # - Use a fixed device number so PipeWire node names (and application permission
    #   grants) are stable across reboots. Exit 17 (EEXIST) is success.
    # - Keep the device alive on stop so apps survive relay restarts via
    #   VIDIOC_DQBUF blocking rather than receiving errors.
    systemd.services.v4l2-relayd-ipu6 = {
      preStart = mkForce ''
        mkdir -p "$(dirname "$V4L2_DEVICE_FILE")"
        ${config.boot.kernelPackages.v4l2loopback.bin}/bin/v4l2loopback-ctl \
          add --name "Intel MIPI Camera" --exclusive-caps=1 ${toString cfg.videoDeviceNumber} || [ $? -eq 17 ]
        echo /dev/video${toString cfg.videoDeviceNumber} > "$V4L2_DEVICE_FILE"
      '';
      postStop = mkForce ''
        rm -rf "$(dirname "$V4L2_DEVICE_FILE")"
      '';
    };

  };
}
+5 −0
Original line number Diff line number Diff line
@@ -221,6 +221,11 @@ in
      boot = mkIf ((length enabledInstances) > 0) {
        extraModulePackages = [ kernelPackages.v4l2loopback ];
        kernelModules = [ "v4l2loopback" ];
        # Prevent v4l2loopback from auto-creating a device at load time. An
        # unconfigured device has a degenerate framerate range that breaks
        # GStreamer caps negotiation. All devices are created at runtime via
        # v4l2loopback-ctl add in each instance's preStart instead.
        extraModprobeConfig = "options v4l2loopback devices=0";
      };

      systemd.services = mkInstanceServices enabledInstances;