Created attachment 186189 [details] This is the full output of running journalctl SUMMARY KWin/Wayland 6.5.0: DisplayPort monitor freezes on HDMI or Thunderbolt hot-plug, amdgpu "Mode Validation Warning" in logs STEPS TO REPRODUCE 1. Start a Plasma (Wayland) session on a computer with an AMD Ryzen 5 7430u (Renoir graphics). 2. Use a single monitor connected via DisplayPort (e.g., 3440x1440 @ 120Hz). 3. Once the desktop is active, hot-plug a second monitor into the HDMI port. OBSERVED RESULT The primary DisplayPort monitor freezes after a moment. The image is static and does not update. The newly connected HDMI monitor does not receive a signal (remains black). The system itself does not crash (e.g., the mouse cursor can still move, but its image is not updated on the frozen screen). Unplugging the HMDI or thunderbolt cable returns everything to normal on the DisplayPort connection. The kernel log (journalctl -k -b -1 | grep -iE "(amdgpu|drm|kwin|error|failed)") shows the following error spammed at the moment of the hot-plug: amdgpu 0000:05:00.0: [drm] Mode Validation Warning: Total vertical active bandwidth failed validation. EXPECTED RESULT Both monitors should become active. The Plasma desktop should extend or mirror to the newly connected HDMI or Thunderbolt monitor, and the primary DisplayPort monitor should remain responsive. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Arch Linux running 6.17.5.arch1-1 KDE Plasma Version: 6.5.0 KDE Frameworks Version: 6.19.0 Qt Version: 6.10.0 ADDITIONAL INFORMATION 1. This is a Wayland-Specific issue: This bug ONLY occurs in the Plasma (Wayland) session. The exact same hot-plug procedure in a Plasma (X11) session works perfectly every time. 2. As far as I can tell, this is not a new kernel issue: This bug was tested and confirmed on two different kernels: linux (mainline): 6.17.5-arch1-1 linux-lts (Long-Term Support) The behavior is identical on both kernels. 3. Hardware: Machine: Blackview MP100 mini pc CPU/APU: AMD Ryzen 5 7430u with Radeon Graphics (Renoir) 4. KWin Support Information: Version ======= KWin version: 6.5.0 Qt Version: 6.10.0 Qt compile version: 6.10.0 XCB compile version: 1.17.0 Operation Mode: Wayland Output backend ============== Name: DRM Atomic Mode Setting on GPU 0: true Screens ======= Number of Screens: 1 Screen 0: --------- Name: DP-1 Enabled: 1 Geometry: 0,0,3440x1440 Physical size: 797x334mm Scale: 1 Refresh Rate: 120000 Adaptive Sync: never Compositing =========== Compositing is active Compositing Type: OpenGL OpenGL vendor string: AMD OpenGL renderer string: AMD Radeon Graphics (radeonsi, renoir, ACO, DRM 3.64, 6.17.5-arch1-1) OpenGL version string: 4.6 (Core Profile) Mesa 25.2.5-arch1.2 OpenGL platform interface: EGL OpenGL shading language version string: 4.60 Driver: Unknown GPU class: Unknown OpenGL version: 4.6 GLSL version: 4.60 Mesa version: 25.2.5 X server version: 1.24.1 Linux kernel version: 6.17.5 Direct rendering: Requires strict binding: no Virtual Machine: no OpenGL 2 Shaders are used
Please verify that it's still an issue in 6.5.2, we found and fixed a regression in regard to bandwidth limits, which might be relevant. If it still happens, - attach the output of "journalctl --user-unit plasma-kwin_wayland --boot 0" after reproducing the problem - follow https://invent.kde.org/plasma/kwin/-/wikis/Debugging/Debugging-DRM-issues to get a drm debug log of the issue
Created attachment 186609 [details] Plasma Kwin Wayland Boot journalctl output This is the output of running journalctl --user-unit plasma-kwin_wayland --boot 0
Created attachment 186610 [details] DRM debug info This is the output of running the DRM debug commands
(In reply to Zamundaaa from comment #1) > Please verify that it's still an issue in 6.5.2, we found and fixed a > regression in regard to bandwidth limits, which might be relevant. If it > still happens, > - attach the output of "journalctl --user-unit plasma-kwin_wayland --boot 0" > after reproducing the problem > - follow > https://invent.kde.org/plasma/kwin/-/wikis/Debugging/Debugging-DRM-issues to > get a drm debug log of the issue Sorry for the delay, I had to wait for the the latest version in Arch. Unfortunately upgrading to 6.5.2 did not resolve the issue. I think it may be useful to bring up that it works perfectly fine using the Gnome desktop, so it isn't an AMD driver issue AFAIK. I've added the requested information. Please let me know if you need anything else.
I'm not sure if I'm supposed to change the status back to reported? I think I am
Alright, so bandwidth is the problem: [ 129.170690] amdgpu 0000:05:00.0: [drm] Mode Validation Warning: Total vertical active bandwidth failed validation. [ 129.170693] amdgpu 0000:05:00.0: [drm:amdgpu_dm_atomic_check [amdgpu]] DC global validation failure: The operation is not supported. (24) [ 129.170881] [drm:sdma_v4_0_process_trap_irq [amdgpu]] IH: SDMA trap [ 129.170915] amdgpu 0000:05:00.0: [drm:amdgpu_dm_atomic_check [amdgpu]] Atomic check failed with err: -22 Afaik "Total vertical active bandwidth" refers to the GPU side and not the cable/display, so the format+modifier changes should've helped. Does limiting color resolution on either display help? Also, which "color accuracy" setting are you using? About the DisplayPort screen freezing after this happens, from the log it seems like KWin continues to present new frames just fine, so that bit might actually be a driver bug.
🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME. For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging. Thank you for helping us make KDE software even better for everyone!
🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.