Direct Scanout not working on Hybrid Laptop (AMD/Nvidia)

Description

So Direct Scanout is not working on KDE/Gnome when you use dGPU Nvidia to render the game, but works on igpu (radeon) but it works fine If i have Intel IGPU and Nvidia DGPU, only not working with AMD Configuration

More information is here

Regression

Works with Intel/Nvidia configuration but doesn’t work for Amd/Nvidia configuration

Step for reproduction

1- Run the game on Nvidia dgpu (prime-run) on the laptop with amd igpu

2- qdbus org.kde.KWin /KWin showDebugConsole Type this in console, maybe qdbus6 for newer system

3- Go to effects tab and enable showcompositing

4- Check if the Compositing on top right goes away or no, if no mean direct scanout not working

5- Work when the game is run on igpu

System information

╰─❮ inxi -GSC -xx
System:
  Host: syntist-laptop Kernel: 6.19.3-2-cachyos arch: x86_64 bits: 64
    compiler: clang v: 21.1.8
  Desktop: KDE Plasma v: 6.6.0 tk: Qt v: N/A wm: kwin_wayland dm: SDDM
    Distro: CachyOS base: Arch Linux
CPU:
  Info: 6-core model: AMD Ryzen 5 6600H with Radeon Graphics bits: 64
    type: MT MCP arch: Zen 3+ rev: 1 cache: L1: 384 KiB L2: 3 MiB L3: 16 MiB
  Speed (MHz): avg: 3676 min/max: 413/4566 boost: enabled cores: 1: 3676
    2: 3676 3: 3676 4: 3676 5: 3676 6: 3676 7: 3676 8: 3676 9: 3676 10: 3676
    11: 3676 12: 3676 bogomips: 79050
  Flags-basic: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a
    ssse3 svm
Graphics:
  Device-1: NVIDIA GA107M [GeForce RTX 3050 Mobile] vendor: Lenovo
    driver: nvidia v: 590.48.01 arch: Ampere pcie: speed: 16 GT/s lanes: 8
    ports: active: none empty: HDMI-A-1 bus-ID: 01:00.0 chip-ID: 10de:25a2
  Device-2: Advanced Micro Devices [AMD/ATI] Rembrandt [Radeon 680M]
    vendor: Lenovo driver: amdgpu v: kernel arch: RDNA-2 pcie: speed: 16 GT/s
    lanes: 16 ports: active: DP-2,eDP-1 empty: DP-1, DP-3, DP-4, DP-5, DP-6,
    DP-7, DP-8, Writeback-1 bus-ID: 06:00.0 chip-ID: 1002:1681 temp: 56.0 C
  Device-3: Chicony Integrated Camera driver: uvcvideo type: USB rev: 2.0
    speed: 480 Mb/s lanes: 1 bus-ID: 1-3:2 chip-ID: 04f2:b6c2
  Display: wayland server: X.org v: 1.21.1.21 with: Xwayland v: 24.1.9
    compositor: kwin_wayland driver: gpu: amdgpu d-rect: 4480x2520 display-ID: 0
  Monitor-1: DP-2 pos: primary,top-left model: Acer EI322QUR res: 2560x1440
    hz: 165 dpi: 93 diag: 806mm (31.7")
  Monitor-2: eDP-1 pos: bottom-r model: Lenovo 0x9059 res: 1920x1080 hz: 120
    dpi: 142 diag: 395mm (15.5")
  API: EGL v: 1.5 platforms: device: 0 drv: nvidia device: 1 drv: radeonsi
    device: 3 drv: swrast gbm: drv: kms_swrast surfaceless: drv: nvidia wayland:
    drv: radeonsi x11: drv: radeonsi inactive: device-2
  API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: amd mesa v: 26.1.0-devel
    glx-v: 1.4 direct-render: yes renderer: AMD Radeon 660M (radeonsi rembrandt
    ACO DRM 3.64 6.19.3-2-cachyos) device-ID: 1002:1681 display-ID: :0.0
  API: Vulkan v: 1.4.341 surfaces: N/A device: 0 type: integrated-gpu
    driver: mesa radv device-ID: 1002:1681 device: 1 type: discrete-gpu
    driver: nvidia device-ID: 10de:25a2 device: 2 type: cpu
    driver: mesa llvmpipe device-ID: 10005:0000
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
    de: kscreen-console,kscreen-doctor gpu: lact, nvidia-settings, nvidia-smi,
    radeontop wl: wayland-info x11: xdpyinfo, xprop, xrandr