| Summary: | Wayland screen corruption, dual output, dual GPU, different screen resolution | ||
|---|---|---|---|
| Product: | [Plasma] kwin | Reporter: | Stefan Hoffmeister <stefan.hoffmeister> |
| Component: | wayland-generic | Assignee: | KWin default assignee <kwin-bugs-null> |
| Status: | RESOLVED DUPLICATE | ||
| Severity: | normal | CC: | nate, ngompa13, rommy, xaver.hugl |
| Priority: | NOR | ||
| Version First Reported In: | 5.27.3 | ||
| Target Milestone: | --- | ||
| Platform: | Fedora RPMs | ||
| OS: | Linux | ||
| Latest Commit: | Version Fixed In: | ||
| Sentry Crash Report: | |||
| Attachments: |
Screen content corruption
drm_info output of system affected picture of corruption |
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Created attachment 157564 [details]
drm_info output of system affected
Added drm_info output which might be more effective in communicating the setup than prose.
Note: _drawing_ something that is "alive" works just perfectly fine - so putting real content into those affected areas renders just fine. It's, for whatever reason, only whenever content is _not_ painted there that the corruption becomes visible. Leaving, say, a Youtube video playing in the affected areas (i.e. continuous refreshing of that area) results in no corruption. Leaving an empty / idle Kate window in that exact same area will also result in screen corruption over that area, until (in this example) the Kate window gets repainted. https://www.reddit.com/r/Fedora/comments/12j8j1n/have_you_guys_seen_this_screen_glitch_in_kde_what/?utm_source=share&utm_medium=web2x&context=3 looks interesting and possibly related - the symptoms are very similar. Note that the Reddit thread talks about an AMD RX5700 eGPU, attached to a laptop. Created attachment 158056 [details]
picture of corruption
attachment showing my occurrence. the top left seems to work reliably and is about the size of my laptops display
(In reply to Stefan Hoffmeister from comment #3) > https://www.reddit.com/r/Fedora/comments/12j8j1n/ > have_you_guys_seen_this_screen_glitch_in_kde_what/ > ?utm_source=share&utm_medium=web2x&context=3 looks interesting and possibly > related - the symptoms are very similar. > > Note that the Reddit thread talks about an AMD RX5700 eGPU, attached to a > laptop. Hi, I am the reddit poster here. about info below: Operating System: Fedora Linux 37 KDE Plasma Version: 5.27.4 KDE Frameworks Version: 5.104.0 Qt Version: 5.15.8 Kernel Version: 6.2.9-200.fc37.x86_64 (64-bit) Graphics Platform: Wayland Processors: 20 × 12th Gen Intel® Core™ i7-1280P Memory: 62.5 GiB of RAM Graphics Processor: AMD Radeon RX 5700 Manufacturer: Framework Product Name: Laptop (12th Gen Intel Core) System Version: A8 I am happy to provide any debug info that would be useful. This happens just about every time I use my computer so I can reproduce it easily *** Bug 473736 has been marked as a duplicate of this bug. *** *** This bug has been marked as a duplicate of bug 469623 *** |
Created attachment 157562 [details] Screen content corruption KDE / Wayland seems to reliably get confused about which screen is attached to which output in a multi-GPU setup. This materializes in bad / wrong / missing invalidation of painting areas, leaving content garbage in place, and also results in "impossible" state where Spectacle as a screenshotter claims part of a very much existing screen as _transparent_. The attached screenshot shows the broken state; notice * the red frame I painted in to show the middle screen ("screen #2") in a triple screen setup * the bottom-right corner of screen #2, which Spectacle sees as transparent - but which it is not * the corruption elsewhere on screen #2 Now particularly note the "clean" area on screen #2 - the dimensions here are exactly the same as the dimensions of the screen to the left ("screen #3"). AFAICT, this implies that KWin incorrectly uses the dimensions of screen #3 to compute damage / paint / invalidation areas on screen #2. This then leads to garbage artefacts on the (larger) screen #2. Key to reproducing this probably is, unfortunately, a GPU setup where * iGPU = Intel * dGPU = Nvidia and where * screen #1 == laptop == Intel (right-most screen) * screen #2 == HDMI port _connected to Intel_ * screen #3 == DisplayPort port _connected to NVIDIA_ and where I used "KWIN_DRM_DEVICES=/dev/dri/card1:/dev/dri/card0" to force the NVIDIA GPU as the primary GPU (without this forcing, the Intel GPU becomes primary) There is no internal mux on the notebook; the outputs are hardwired. In that setup, the NVIDIA card draws everything, draws natively on screen #3, and passes data for screen #2 and screen #1 to the Intel GPU for output. ******* For the sake of disclosure, the screenshot comes from a bit of additional peculiar set of steps - but it highlights much better the exact same effect seen during "normal operations" with the above setup: The damage / paint area when drawing on screen #2 is taken from screen #3. The peculiarity is physically turning off screen #3 (the left-most screen), and the Thunderbolt docking station apparently keeps some kind of connection alive, which results in screen #3 still being "seen". But again, I see structurally the same corruption if I don't do that - it's just so much more evident with that peculiar step. I have no idea why I never see corruption on screen #1 or screen #3.