| Summary: | Intense glitches when connectes to an external monitor | ||
|---|---|---|---|
| Product: | [Plasma] kwin | Reporter: | Filippo <spaceshuttlee> |
| Component: | wayland-generic | Assignee: | KWin default assignee <kwin-bugs-null> |
| Status: | RESOLVED WORKSFORME | ||
| Severity: | normal | CC: | xaver.hugl |
| Priority: | NOR | Keywords: | multiscreen, usability |
| Version First Reported In: | unspecified | ||
| Target Milestone: | --- | ||
| Platform: | Other | ||
| OS: | Linux | ||
| Latest Commit: | Version Fixed/Implemented In: | ||
| Sentry Crash Report: | |||
| Attachments: |
Video showing the bug on Fedora 43. On Arch it's exactly the same
Same glitch happening on Konsole |
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Created attachment 186555 [details]
Same glitch happening on Konsole
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/8379 Do you have any environment variables set for KWin? We've had some similar glitches with triple buffering on NVidia, which is why it's off by default. (In reply to Zamundaaa from comment #3) > Do you have any environment variables set for KWin? We've had some similar > glitches with triple buffering on NVidia, which is why it's off by default. No, I have not set any Environment Variables on my own. Git commit 5ca05f8fd822b35012ad92f425dd8556f56ad809 by Xaver Hugl. Committed on 10/11/2025 at 23:09. Pushed by zamundaaa into branch 'master'. backends/drm: add environment variables to debug potential synchronization issues Specifically, KWIN_DRM_FORCE_GL_FINISH_MGPU_COPY, to force glFinish before doing multi GPU copies, and KWIN_DRM_FORCE_GL_FINISH_PRESENT to force glFinish before presenting a buffer to the screen. Related: bug 511010 M +7 -4 src/backends/drm/drm_egl_layer_surface.cpp https://invent.kde.org/plasma/kwin/-/commit/5ca05f8fd822b35012ad92f425dd8556f56ad809 A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/8406 Git commit b3725f628d6daca2d1853a0a0b74753321af358c by Xaver Hugl. Committed on 11/11/2025 at 01:29. Pushed by zamundaaa into branch 'Plasma/6.5'. backends/drm: add environment variables to debug potential synchronization issues Specifically, KWIN_DRM_FORCE_GL_FINISH_MGPU_COPY, to force glFinish before doing multi GPU copies, and KWIN_DRM_FORCE_GL_FINISH_PRESENT to force glFinish before presenting a buffer to the screen. Related: bug 511010 (cherry picked from commit 5ca05f8fd822b35012ad92f425dd8556f56ad809) Co-authored-by: Xaver Hugl <xaver.hugl@kde.org> M +7 -4 src/backends/drm/drm_egl_layer_surface.cpp https://invent.kde.org/plasma/kwin/-/commit/b3725f628d6daca2d1853a0a0b74753321af358c 🐛🧹 ⚠️ 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. |
Created attachment 186554 [details] Video showing the bug on Fedora 43. On Arch it's exactly the same SUMMARY When my laptop is connected to an external monitor (both in single monitor and in clamshell mode) various graphical glitches occur. This was tested both on Arch Linux and on Fedora 43, both on wayland and both with open source drivers; no proprietary nVidia drivers were involved. Machine Specs: CPU: Intel Core i5 8300H; GPU(s): Intel Graphics 630, Nvidia GeForce GTX 1050Ti External monitor: Acer VG340Y; Resolution: 1920x1080; Refresh Rate: 75Hz (though the problem persists at 60Hz). That said, the same glitch occurs with other external displays. I've tested serveral other desktop environments and compositors including Sway, Gnome and Xfce and this seems to be a Plasma-specific issue. STEPS TO REPRODUCE A few cases where the glitch is most notable 1. Right click for the contect menu and hover over the various elements. 2. Open up the terminal and start typing. 3. Shake the cursor to enlarge it OBSERVED RESULT Annoying glitches as pictured in the attachments. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Arch Linux [Kernel 6.17.7] / Fedora 43 KDE Plasma Version: 6.5.1 on Arch / 6.4 on Fedora KDE Frameworks Version: 6.19 on Arch Qt Version: 6.10 KINFO DETAILS Block 0, Base EDID: EDID Structure Version & Revision: 1.3 Vendor & Product Identification: Manufacturer: ACR Model: 1776 Serial Number: 58761330 (0x0380a072) Made in: week 38 of 2020 Basic Display Parameters & Features: Digital display Maximum image size: 53 cm x 30 cm Gamma: 2.20 DPMS levels: Off RGB color display Default (sRGB) color space is primary color space First detailed timing is the preferred timing Color Characteristics: Red : 0.6523, 0.3369 Green: 0.3134, 0.6259 Blue : 0.1513, 0.0664 White: 0.3134, 0.3291 Established Timings I & II: IBM : 720x400 70.081663 Hz 9:5 31.467 kHz 28.320000 MHz DMT 0x04: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz Apple : 640x480 66.666667 Hz 4:3 35.000 kHz 30.240000 MHz DMT 0x05: 640x480 72.808802 Hz 4:3 37.861 kHz 31.500000 MHz DMT 0x06: 640x480 75.000000 Hz 4:3 37.500 kHz 31.500000 MHz DMT 0x08: 800x600 56.250000 Hz 4:3 35.156 kHz 36.000000 MHz DMT 0x09: 800x600 60.316541 Hz 4:3 37.879 kHz 40.000000 MHz DMT 0x0a: 800x600 72.187572 Hz 4:3 48.077 kHz 50.000000 MHz DMT 0x0b: 800x600 75.000000 Hz 4:3 46.875 kHz 49.500000 MHz Apple : 832x624 74.551266 Hz 4:3 49.726 kHz 57.284000 MHz DMT 0x10: 1024x768 60.003840 Hz 4:3 48.363 kHz 65.000000 MHz DMT 0x11: 1024x768 70.069359 Hz 4:3 56.476 kHz 75.000000 MHz DMT 0x12: 1024x768 75.028582 Hz 4:3 60.023 kHz 78.750000 MHz DMT 0x24: 1280x1024 75.024675 Hz 5:4 79.976 kHz 135.000000 MHz Apple : 1152x870 75.061550 Hz 192:145 68.681 kHz 100.000000 MHz Standard Timings: DMT 0x15: 1152x864 75.000000 Hz 4:3 67.500 kHz 108.000000 MHz DMT 0x20: 1280x960 60.000000 Hz 4:3 60.000 kHz 108.000000 MHz DMT 0x23: 1280x1024 60.019740 Hz 5:4 63.981 kHz 108.000000 MHz DMT 0x55: 1280x720 60.000000 Hz 16:9 45.000 kHz 74.250000 MHz DMT 0x1c: 1280x800 59.810326 Hz 16:10 49.702 kHz 83.500000 MHz DMT 0x2f: 1440x900 59.887445 Hz 16:10 55.935 kHz 106.500000 MHz DMT 0x3a: 1680x1050 59.954250 Hz 16:10 65.290 kHz 146.250000 MHz DMT 0x52: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz Detailed Timing Descriptors: DTD 1: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz (527 mm x 296 mm) Hfront 88 Hsync 44 Hback 148 Hpol P Vfront 4 Vsync 5 Vback 36 Vpol P Display Range Limits: Monitor ranges (GTF): 56-76 Hz V, 30-85 kHz H, max dotclock 220 MHz Display Product Name: 'VG240Y' Display Product Serial Number: 'TG5EE0018524' Extension blocks: 1 Checksum: 0x40 ADDITIONAL INFORMATION For any additional tests and information please let me know, as I'm unsure what else could be useful.