Dock background blinks when Greyscale filter is enabled

[lobre]

What Happened?

When the Greyscale display filter is turned on (and the slider moved toward "Less Colour"), the dock background starts blinking between light and dark shades. This happens as soon as the dock is visible and I move the mouse around. I suspect it's related to the new blur effect added to the dock background.

Steps to Reproduce

1. Open Displays → Filters.
2. Enable Greyscale and move the slider toward "Less Colour".
3. Make sure the dock is visible (not covered by any window).
4. Move the mouse around the screen.

Expected Behavior

The dock background should stay stable and not flicker or change shades.

OS Version

8.x (Circe)

OS Architecture

amd64 (on most hardwares)

Session Type

Secure Session (Wayland)

Software Version

Latest release (I have run all updates)

Log Output

Hardware Info

No response

[lobre]

Here is a video to demonstrate the bug:

grey_flicker.webm

[LuminousHustler]

I cannot reproduce. That said I tested with:

• AMD hardware (mesa drivers) + X11
• Gnome Boxes + Wayland

Out of curiosity, do you happen to have an NVidia graphics card?

[lobre]

No, I don’t have an NVIDIA GPU.

This is on Intel integrated graphics (Meteor Lake / Intel Arc) using Mesa.

I can reproduce it consistently on my machine, including on both internal and external displays.

Here is more info about my graphical stack.

$ glxinfo -B

name of display: :0
display: :0  screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel (0x8086)
    Device: Mesa Intel(R) Arc(tm) Graphics (MTL) (0x7d55)
    Version: 25.0.7
    Accelerated: yes
    Video memory: 15771MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.6
    Max compat profile version: 4.6
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2
OpenGL vendor string: Intel
OpenGL renderer string: Mesa Intel(R) Arc(tm) Graphics (MTL)
OpenGL core profile version string: 4.6 (Core Profile) Mesa 25.0.7-0ubuntu0.24.04.2
OpenGL core profile shading language version string: 4.60
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

OpenGL version string: 4.6 (Compatibility Profile) Mesa 25.0.7-0ubuntu0.24.04.2
OpenGL shading language version string: 4.60
OpenGL context flags: (none)
OpenGL profile mask: compatibility profile

OpenGL ES profile version string: OpenGL ES 3.2 Mesa 25.0.7-0ubuntu0.24.04.2
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20

$ vulkaninfo --summary

==========
VULKANINFO
==========

Vulkan Instance Version: 1.3.275


Instance Extensions: count = 24
-------------------------------
VK_EXT_acquire_drm_display             : extension revision 1
VK_EXT_acquire_xlib_display            : extension revision 1
VK_EXT_debug_report                    : extension revision 10
VK_EXT_debug_utils                     : extension revision 2
VK_EXT_direct_mode_display             : extension revision 1
VK_EXT_display_surface_counter         : extension revision 1
VK_EXT_headless_surface                : extension revision 1
VK_EXT_surface_maintenance1            : extension revision 1
VK_EXT_swapchain_colorspace            : extension revision 5
VK_KHR_device_group_creation           : extension revision 1
VK_KHR_display                         : extension revision 23
VK_KHR_external_fence_capabilities     : extension revision 1
VK_KHR_external_memory_capabilities    : extension revision 1
VK_KHR_external_semaphore_capabilities : extension revision 1
VK_KHR_get_display_properties2         : extension revision 1
VK_KHR_get_physical_device_properties2 : extension revision 2
VK_KHR_get_surface_capabilities2       : extension revision 1
VK_KHR_portability_enumeration         : extension revision 1
VK_KHR_surface                         : extension revision 25
VK_KHR_surface_protected_capabilities  : extension revision 1
VK_KHR_wayland_surface                 : extension revision 6
VK_KHR_xcb_surface                     : extension revision 6
VK_KHR_xlib_surface                    : extension revision 6
VK_LUNARG_direct_driver_loading        : extension revision 1

Instance Layers: count = 3
--------------------------
VK_LAYER_INTEL_nullhw       INTEL NULL HW                1.1.73   version 1
VK_LAYER_MESA_device_select Linux device selection layer 1.4.303  version 1
VK_LAYER_MESA_overlay       Mesa Overlay layer           1.4.303  version 1

Devices:
========
GPU0:
	apiVersion         = 1.4.305
	driverVersion      = 25.0.7
	vendorID           = 0x8086
	deviceID           = 0x7d55
	deviceType         = PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU
	deviceName         = Intel(R) Arc(tm) Graphics (MTL)
	driverID           = DRIVER_ID_INTEL_OPEN_SOURCE_MESA
	driverName         = Intel open-source Mesa driver
	driverInfo         = Mesa 25.0.7-0ubuntu0.24.04.2
	conformanceVersion = 1.4.0.0
	deviceUUID         = 8680557d-0800-0000-0002-000000000000
	driverUUID         = 802b0057-40c2-aed9-e538-d78b797f04f4
GPU1:
	apiVersion         = 1.4.305
	driverVersion      = 0.0.1
	vendorID           = 0x10005
	deviceID           = 0x0000
	deviceType         = PHYSICAL_DEVICE_TYPE_CPU
	deviceName         = llvmpipe (LLVM 20.1.2, 256 bits)
	driverID           = DRIVER_ID_MESA_LLVMPIPE
	driverName         = llvmpipe
	driverInfo         = Mesa 25.0.7-0ubuntu0.24.04.2 (LLVM 20.1.2)
	conformanceVersion = 1.3.1.1
	deviceUUID         = 6d657361-3235-2e30-2e37-2d3075627500
	driverUUID         = 6c6c766d-7069-7065-5555-494400000000

$ inxi -Gxx

Graphics:
  Device-1: Intel Meteor Lake-P [Intel Arc Graphics] vendor: Dell driver: i915
    v: kernel arch: Gen-13 ports: active: DP-11,DP-8 off: eDP-1 empty: DP-1,
    DP-10, DP-12, DP-2, DP-3, DP-4, DP-5, DP-6, HDMI-A-1 bus-ID: 0000:00:02.0
    chip-ID: 8086:7d55
  Device-2: Logitech BRIO 4K Stream Edition
    driver: hid-generic,snd-usb-audio,usbhid,uvcvideo type: USB rev: 3.1
    speed: 5 Gb/s lanes: 1 bus-ID: 2-1.4.3.1:13 chip-ID: 046d:086b
  Device-3: Realtek Integrated_Webcam_FHD driver: uvcvideo type: USB
    rev: 2.0 speed: 480 Mb/s lanes: 1 bus-ID: 3-7:5 chip-ID: 0bda:5583
  Display: wayland server: X.org v: 1.21.1.11 with: Xwayland v: 23.2.6
    compositor: gala v: 8.4.0 driver: X: loaded: modesetting
    unloaded: fbdev,vesa dri: iris gpu: i915 display-ID: 0
  Monitor-1: DP-11 model: LG (GoldStar) HDR 4K res: 3840x2160 dpi: 163
    diag: 690mm (27.2")
  Monitor-2: DP-8 model: LG (GoldStar) ULTRAGEAR res: 2560x1440 dpi: 109
    diag: 685mm (27")
  Monitor-3: eDP-1 model: ChiMei InnoLux 0x1466 res: 2880x1800 dpi: 243
    diag: 355mm (14")
  API: EGL v: 1.5 platforms: device: 0 drv: iris device: 1 drv: swrast gbm:
    drv: iris surfaceless: drv: iris wayland: drv: iris x11: drv: iris
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: intel mesa
    v: 25.0.7-0ubuntu0.24.04.2 glx-v: 1.4 direct-render: yes renderer: Mesa
    Intel Arc Graphics (MTL) device-ID: 8086:7d55 display-ID: :0.0
  API: Vulkan v: 1.3.275 surfaces: xcb,xlib,wayland device: 0
    type: integrated-gpu driver: N/A device-ID: 8086:7d55 device: 1 type: cpu
    driver: N/A device-ID: 10005:0000

Let me know if there’s anything I can try or collect on my side to help, since I can reproduce it reliably.

Also worth noting: I’m starting to notice similar flickering outside of the dock as well, so it might not be dock-specific but something more general in the compositor or rendering path.

[lobre]

See this new screen recording:

Kooha-2026-01-02-16-34-30.webm

[LuminousHustler]

I'm marking the priority on this has a high, because the screen recording is pretty jarring even though I don't have this issue on my machine. It looks like the entire desktop environment freaks out, not just the dock to be honest. When the issue is happening on your machine, could you run these two commands to grab the log files for both the dock and gala please?

This should put a text file called dock.txt in your home directory:
journalctl -b /usr/bin/io.elementary.dock > ~/dock.txt

This should put a text file called gala.txt in your home directory:
journalctl -b /usr/bin/gala > ~/gala.txt

[lobre]

Today, when trying to reproduce again to answer your comment, I see a slighly different artifact. Here is the new screencast below. You see that only a small rectangle with rounded borders, just above the dock has the issue.

I have also recorded from my phone's camera, as a lot of stutter comes from the actual recording software apparently, which is Kooha (don't know if normal and if part of the issue).

Also, see attached the dock.txt and gala.txt.

gala.txt
dock.txt

[lobre]

Hmm, in fact, even after having disabled greyscale, I still see this rectangle zone acting weird with a blur.

Same, if I do a screenshot, it will not reveal. So it means it is more of a compositor artifact.

But the more I try to reproduce, the more it is different, which won't help a lot.

[lobre]

After restart, the issue comes back close to my initial reporting. We see that the background of the dock reflects the window that is being moved kind of.