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[BUG] VRR flickering (erratic refresh rate change) #796

@avat3r

Description

@avat3r

Pre-flight checklist

  • I have searched existing issues and this is not a duplicate.
  • I have read the Contributing Guidelines.
  • I have verified the issue is reproducible with the latest available CachyOS kernel.

Upstream / vanilla kernel check

I was unable to test with a vanilla/upstream kernel

Kernel variant

linux-cachyos (EEVDF, Clang)

System information (cachyos-bugreport.sh)

System:
  Kernel: 6.19.10-1-cachyos arch: x86_64 bits: 64 compiler: clang v: 22.1.1
    clocksource: tsc avail: hpet,acpi_pm
    parameters: video=DP-1:3440x1440@143.92Hz quiet nowatchdog splash rw
    rootflags=subvol=/@ root=UUID=28c387e7-665a-402a-a0f1-bfafae4a0a02
  Desktop: KDE Plasma v: 6.6.3 tk: Qt v: N/A wm: kwin_wayland with: krunner
    dm: SDDM Distro: CachyOS base: Arch Linux
Machine:
  Type: Desktop Mobo: Gigabyte model: B550 AORUS ELITE AX V2 v: x.x
    serial: N/A uuid: 03560274-043c-0533-4c06-330700080009 Firmware: UEFI
    vendor: American Megatrends LLC. v: F17c date: 03/23/2023
CPU:
  Info: model: AMD Ryzen 7 5800X3D socket: AM4 bits: 64 type: MT MCP
    arch: Zen 3+ gen: 3 level: v3 note: check built: 2022 process: TSMC n6 (7nm)
    family: 0x19 (25) model-id: 0x21 (33) stepping: 2 microcode: 0xA201211
  Topology: cpus: 1x dies: 1 clusters: 1 cores: 8 threads: 16 tpc: 2
    smt: enabled cache: L1: 512 KiB desc: d-8x32 KiB; i-8x32 KiB L2: 4 MiB
    desc: 8x512 KiB L3: 96 MiB desc: 1x96 MiB
  Speed (MHz): avg: 3590 min/max: 576/4553 boost: enabled
    base/boost: 3400/3400 scaling: driver: amd-pstate-epp governor: performance
    volts: 1.1 V ext-clock: 100 MHz cores: 1: 3590 2: 3590 3: 3590 4: 3590
    5: 3590 6: 3590 7: 3590 8: 3590 9: 3590 10: 3590 11: 3590 12: 3590
    13: 3590 14: 3590 15: 3590 16: 3590 bogomips: 108596
  Flags-basic: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3
  Vulnerabilities:
  Type: gather_data_sampling status: Not affected
  Type: ghostwrite status: Not affected
  Type: indirect_target_selection status: Not affected
  Type: itlb_multihit status: Not affected
  Type: l1tf status: Not affected
  Type: mds status: Not affected
  Type: meltdown status: Not affected
  Type: mmio_stale_data status: Not affected
  Type: old_microcode status: Not affected
  Type: reg_file_data_sampling status: Not affected
  Type: retbleed status: Not affected
  Type: spec_rstack_overflow mitigation: Safe RET
  Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via
    prctl
  Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer
    sanitization
  Type: spectre_v2 mitigation: Retpolines; IBPB: conditional; IBRS_FW;
    STIBP: always-on; RSB filling; PBRSB-eIBRS: Not affected; BHI: Not
    affected
  Type: srbds status: Not affected
  Type: tsa mitigation: Clear CPU buffers
  Type: tsx_async_abort status: Not affected
  Type: vmscape mitigation: IBPB before exit to userspace
Graphics:
  Device-1: Advanced Micro Devices [AMD/ATI] Navi 21 [Radeon RX 6800/6800 XT
    / 6900 XT] vendor: XFX Speedster MERC 319 driver: amdgpu v: kernel
    arch: RDNA-2 code: Navi-2x process: TSMC n7 (7nm) built: 2020-22 pcie:
    gen: 4 speed: 16 GT/s lanes: 16 ports: active: DP-1 empty: DP-2, DP-3,
    HDMI-A-1, Writeback-1 bus-ID: 09:00.0 chip-ID: 1002:73bf class-ID: 0300
  Display: unspecified server: X.Org v: 24.1.9 with: Xwayland v: 24.1.9
    compositor: kwin_wayland driver: gpu: amdgpu display-ID: :0 screens: 1
  Screen-1: 0 s-res: 3440x1440 s-dpi: 96 s-size: 910x381mm (35.83x15.00")
    s-diag: 987mm (38.84")
  Monitor-1: DP-1 model: LG (GoldStar) ULTRAGEAR serial: <filter>
    built: 2024 res: mode: 3440x1440 hz: 144 scale: 100% (1) dpi: 109 gamma: 1.2
    size: 800x335mm (31.5x13.19") diag: 867mm (34.1") modes: max: 3440x1440
    min: 640x480
  API: EGL v: 1.5 hw: drv: amd radeonsi platforms: device: 0 drv: radeonsi
    device: 1 drv: swrast gbm: drv: radeonsi surfaceless: drv: radeonsi x11:
    drv: radeonsi inactive: wayland
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 26.0.3-arch2.2
    glx-v: 1.4 direct-render: yes renderer: AMD Radeon RX 6900 XT (radeonsi
    navi21 ACO DRM 3.64 6.19.10-1-cachyos) device-ID: 1002:73bf
    memory: 15.62 GiB unified: no
  API: Vulkan v: 1.4.341 layers: 5 device: 0 type: discrete-gpu name: AMD
    Radeon RX 6900 XT (RADV NAVI21) driver: mesa radv v: 26.0.3-arch2.2
    device-ID: 1002:73bf surfaces: N/A
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
    de: kscreen-console,kscreen-doctor gpu: lact wl: wayland-info
    x11: xdpyinfo, xprop, xrandr

Manual system information (if cachyos-bugreport.sh is unavailable)

KDE P

Bug description

Using KDE (Wayland) in CachyOS I expierence a bug again where somehow randomly the VRR (set to automatic or always) starts extreme flickering in the desktop environment and in games and randomly jumps from 144hz to 48 (where the flickering starts).

On the desktop the flickering starts as soon as you don't move the mouse when the bug occur and the OCD shows the HZ is jumping to 48HZ. As soon as I change a window or interact with something animated (or more taxing) like the Steam chat the refresh rate jumps back to 144hz and the flickering disapear. Ingame it is most noticable during loading screens but also ingame when you open a hud element for example. Sometimes a restart can fix this, sometimes not. This happens regardless what launcher (Steam, Faugus, Lutris...) or proton version (currently using CachyOS Proton (latest)) you are using.

I already tested setting KDE to use Vulkan as a renderer but it had no effect. Disabling VRR for specific windows with a rule has helped but does not fix the issue in general. Don't know if this is a CachyOS or KDE specific issue but I know I did not had it on SteamOS or Windows.

Steps to reproduce

Set VRR to automatic or always
Start a game or open a settings windows on desktop and wait a few minutes
Flickering start occuring ingame or on desktop

Expected behavior

No flickering when using VRR

Actual behavior

The refreshrate jumps erratic from 48hz to 144hz

Logs / stack traces


Additional system information

No response

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