Public bug reported:
Problem summary
----------------
CRT-like tearing/artifacting (horizontal bands, shimmer while content scrolls)
on the built-in eDP panel. External DisplayPort monitor is clean. Same
artifacts occur in native GNOME apps (not only browsers). Inside a QEMU VM
running Ubuntu on Wayland, the problem does not occur (virtual GPU path).
Hardware
--------
- System: HP ZBook Ultra G1a 14 inch Mobile Workstation PC
- GPU: AMD Strix Halo / Radeon 8060S (PCI 1002:1586, rev d1)
- Internal panel: eDP-1, LG, 1920x1200 @ ~60 Hz
- External (when connected): DP, HP E45c G5, 5120x1440 @ 165 Hz — no artifacts
Software
--------
- Ubuntu 26.04 LTS
- Affected kernel (current): 6.17.0-29-generic
- Also tested worse on: 7.0.0-15-generic (artifacts more persistent, including
outside Chromium/Electron apps)
- Session: Wayland (XDG_SESSION_TYPE=wayland)
- GNOME Shell 50.1
- Mesa: mesa-vulkan-drivers 26.0.3-1ubuntu1
- Kernel cmdline includes: amdgpu.mes=0 amdgpu.dcdebugmask=0x10
Steps to reproduce
------------------
1. Boot native Ubuntu on Wayland, use built-in display (eDP as primary or only).
2. Open any UI with motion (e.g. Spotify lyrics scrolling, scrolling in browser,
or general desktop animation).
3. Observe CRT-like tearing/horizontal band artifacts on eDP.
4. Move the same app to external DP, or view the same session in a QEMU VM
(Ubuntu guest on Wayland) — artifacts absent in guest / often absent on DP.
Expected: tear-free presentation on eDP, matching external monitor behavior.
Actual: visible tearing/artifacting on eDP only.
Regression notes
----------------
- Problem present on 6.17.0-29-generic (native host).
- Worsened after upgrade to 7.0.0-15-generic (system-wide, not app-specific).
- Reverted default boot to 6.17.0-29; eDP issue remains on host but VM guest
remains clean.
Diagnostic notes
----------------
- Unplugging external monitor does not fix eDP artifacts (rules out mixed-
refresh as sole cause).
- Fractional scaling ruled out (scale 1.0 on both displays).
- Suggests host amdgpu display pipeline / eDP (DC, vblank, PSR) rather than
application or panel failure.
Workarounds tried
-----------------
- amdgpu.dcdebugmask=0x10 and amdgpu.mes=0 on cmdline (already present).
- Booting 6.17 instead of 7.0 (partial improvement vs 7.0, eDP still affected).
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Attachment added: "lspci-vnvn.log"
https://bugs.launchpad.net/bugs/2154424/+attachment/5973967/+files/lspci-vnvn.log
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https://bugs.launchpad.net/bugs/2154424
Title:
eDP CRT-like tearing on HP ZBook Ultra G1a (Strix Halo 8060S), amdgpu,
Wayland
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