Bug 504258 - Garbled, distorted, and/or old framebuffer content shown on the screen after a successful login and before the splash screen/desktop loads
Summary: Garbled, distorted, and/or old framebuffer content shown on the screen after ...
Status: CONFIRMED
Alias: None
Product: kwin
Classification: Plasma
Component: wayland-generic (other bugs)
Version First Reported In: 6.3.5
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-05-15 11:56 UTC by Tech-Tac
Modified: 2025-07-15 08:40 UTC (History)
5 users (show)

See Also:
Latest Commit:
Version Fixed In: 6.3.6
Sentry Crash Report:


Attachments
Noise on Wayland login (3.37 MB, image/jpeg)
2025-05-15 11:56 UTC, Tech-Tac
Details
Garbled screen contents in between SDDM and Plasma loading (3.62 MB, video/webm)
2025-06-24 05:34 UTC, John Kizer
Details
Half green half black (304.34 KB, image/jpeg)
2025-07-13 14:35 UTC, Lucia Mrenica
Details

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Description Tech-Tac 2025-05-15 11:56:11 UTC
Created attachment 181326 [details]
Noise on Wayland login

SUMMARY
When logging in to Plasma Wayland, the first thing to be displayed is a garbled image of whatever was on the screen before, inverted around colors, misplaced regions, some blocks from vram, or just noise if logging in directly after boot without a display manager, with the mouse cursor on top, this usually stays from a few seconds to over 10 seconds, until the desktop loads in.

STEPS TO REPRODUCE
1. Login to the Wayland session
2. Notice screen for the first few seconds

OBSERVED RESULT
Garbled/distorted framebuffer content from the display manager, or the last boot if rebooting (without a display manger, auto login).
It is usually white blocky noise if booting up cleanly and directly to Plasma.

EXPECTED RESULT
Black screen or the desktop

SOFTWARE/OS VERSIONS
Linux: Arch
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.14.0
Qt Version: 6.9.0

ADDITIONAL INFORMATION
Kernel Version: 6.14.6-arch1-1 (64-bit)
Graphics Platform: Wayland
Graphics Processor: AMD ARUBA
Actual GPU model: AMD Radeon HD 7560D
(TeraScale 3 architecture, using the `radeon` driver)
Comment 1 John Kizer 2025-05-19 23:49:33 UTC
I can reproduce on an NVIDIA-only device - it sounds like there are some underlying factors on this one related to how the framebuffer is cleared during the boot-up process, but I'll defer to more knowledgeable folks (this might not be fully controllable within KWin).

Thanks!
Comment 2 Bug Janitor Service 2025-05-22 17:34:21 UTC
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/7672
Comment 3 Zamundaaa 2025-05-23 12:23:28 UTC
Git commit ef88b6425278564096d9394537ca9442d750c0cf by Xaver Hugl.
Committed on 23/05/2025 at 11:17.
Pushed by zamundaaa into branch 'master'.

backends/drm: clear the test buffer with legacy modesetting

With atomic modesetting, we only show the buffer once the compositor has rendered to
it. With legacy modesetting however, the "test" the drm backend does immediately shows
the buffer, so not clearing it may mean we show a frame of random VRAM contents.

M  +6    -0    src/backends/drm/drm_egl_layer_surface.cpp

https://invent.kde.org/plasma/kwin/-/commit/ef88b6425278564096d9394537ca9442d750c0cf
Comment 4 Zamundaaa 2025-05-23 12:46:42 UTC
Git commit 5f994673c521909ebbdd0e6af41d0e27597267ee by Xaver Hugl, on behalf of Xaver Hugl.
Committed on 23/05/2025 at 12:30.
Pushed by zamundaaa into branch 'Plasma/6.4'.

backends/drm: clear the test buffer with legacy modesetting

With atomic modesetting, we only show the buffer once the compositor has rendered to
it. With legacy modesetting however, the "test" the drm backend does immediately shows
the buffer, so not clearing it may mean we show a frame of random VRAM contents.


(cherry picked from commit ef88b6425278564096d9394537ca9442d750c0cf)

Co-authored-by: Xaver Hugl <xaver.hugl@kde.org>

M  +6    -0    src/backends/drm/drm_egl_layer_surface.cpp

https://invent.kde.org/plasma/kwin/-/commit/5f994673c521909ebbdd0e6af41d0e27597267ee
Comment 5 Zamundaaa 2025-05-23 12:47:36 UTC
Git commit 56760937743b42f50f46e2ff2a1fa811502132d7 by Xaver Hugl, on behalf of Xaver Hugl.
Committed on 23/05/2025 at 12:30.
Pushed by zamundaaa into branch 'Plasma/6.3'.

backends/drm: clear the test buffer with legacy modesetting

With atomic modesetting, we only show the buffer once the compositor has rendered to
it. With legacy modesetting however, the "test" the drm backend does immediately shows
the buffer, so not clearing it may mean we show a frame of random VRAM contents.


(cherry picked from commit ef88b6425278564096d9394537ca9442d750c0cf)

Co-authored-by: Xaver Hugl <xaver.hugl@kde.org>

M  +6    -0    src/backends/drm/drm_egl_layer_surface.cpp

https://invent.kde.org/plasma/kwin/-/commit/56760937743b42f50f46e2ff2a1fa811502132d7
Comment 6 Tech-Tac 2025-06-22 13:56:46 UTC
Still present on 6.4.0
Comment 7 TraceyC 2025-06-23 20:05:40 UTC
John, can you still reproduce this on your system? I wasn't / can't on my nvidia gpu system.
Comment 8 John Kizer 2025-06-24 05:34:17 UTC
Created attachment 182585 [details]
Garbled screen contents in between SDDM and Plasma loading

I *think* that's what I'm still experiencing, but I recorded a video to double-check with others and make sure I wasn't misinterpreting :-)

Operating System: Fedora Linux 42
KDE Plasma Version: 6.4.0
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1
Kernel Version: 6.15.3-200.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 6 × Intel® Core™ i5-9400F CPU @ 2.90GHz
Memory: 16 GiB of RAM (15.5 GiB usable)
Comment 9 TraceyC 2025-06-24 16:31:18 UTC
Thanks. Setting this back to confirmed.
Comment 10 Lucia Mrenica 2025-07-13 14:35:36 UTC
Created attachment 183204 [details]
Half green half black

I have a similar issue or maybe the same one, when i lock my system (Meta+L) half of my screen turns green and the other one turns black for like a second or two before the lock screen screen shows. Is it the same issue as this one or separate one? I am on Arch Linux everything up to date, amd gpu laptop. Also there are green glitches in some desktop animations. (Looks the same, half green half black). Furthermore I've tried killing plasmashell and if i do that half of my screen turns green and half is black, Spectacle doesn't capture this only a photo.
Comment 11 repook 2025-07-15 03:41:33 UTC
(In reply to Lucia Mrenica from comment #10)
> Created attachment 183204 [details]
> Half green half black
> 
> I have a similar issue or maybe the same one, when i lock my system (Meta+L)
> half of my screen turns green and the other one turns black for like a
> second or two before the lock screen screen shows. Is it the same issue as
> this one or separate one? I am on Arch Linux everything up to date, amd gpu
> laptop. Also there are green glitches in some desktop animations. (Looks the
> same, half green half black). Furthermore I've tried killing plasmashell and
> if i do that half of my screen turns green and half is black, Spectacle
> doesn't capture this only a photo.

Are your graphics integrated? This seems like a visual issue that occurs with Ryzen processors with Vega integrated graphics on Wayland. Specifically when connected to external monitors. This is only speculation because I searched "green" on Reddit and there is 3 posts on the issue with all of them suggesting that they're using Vega (2200g, 3400g, etc). 

I have the same issue with my laptop as well:

Operating System: Fedora Linux 42
KDE Plasma Version: 6.4.2
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1
Kernel Version: 6.15.5-200.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 8 × AMD Ryzen 5 3500U with Radeon Vega Mobile Gfx
Memory: 12 GiB of RAM (9.6 GiB usable)
Graphics Processor: AMD Radeon Vega 8 Graphics
Comment 12 Lucia Mrenica 2025-07-15 05:55:10 UTC
(In reply to repook from comment #11)
> (In reply to Lucia Mrenica from comment #10)
> > Created attachment 183204 [details]
> > Half green half black
> > 
> > I have a similar issue or maybe the same one, when i lock my system (Meta+L)
> > half of my screen turns green and the other one turns black for like a
> > second or two before the lock screen screen shows. Is it the same issue as
> > this one or separate one? I am on Arch Linux everything up to date, amd gpu
> > laptop. Also there are green glitches in some desktop animations. (Looks the
> > same, half green half black). Furthermore I've tried killing plasmashell and
> > if i do that half of my screen turns green and half is black, Spectacle
> > doesn't capture this only a photo.
> 
> Are your graphics integrated? This seems like a visual issue that occurs
> with Ryzen processors with Vega integrated graphics on Wayland. Specifically
> when connected to external monitors. This is only speculation because I
> searched "green" on Reddit and there is 3 posts on the issue with all of
> them suggesting that they're using Vega (2200g, 3400g, etc). 
> 
> I have the same issue with my laptop as well:
> 
> Operating System: Fedora Linux 42
> KDE Plasma Version: 6.4.2
> KDE Frameworks Version: 6.16.0
> Qt Version: 6.9.1
> Kernel Version: 6.15.5-200.fc42.x86_64 (64-bit)
> Graphics Platform: Wayland
> Processors: 8 × AMD Ryzen 5 3500U with Radeon Vega Mobile Gfx
> Memory: 12 GiB of RAM (9.6 GiB usable)
> Graphics Processor: AMD Radeon Vega 8 Graphics

Yes I am I have a Ryzen 5 3550H and I am connected to an external monitor. Is this an issue with Mesa or the kernel then?
Comment 13 repook 2025-07-15 08:40:41 UTC
(In reply to Lucia Mrenica from comment #12)
> (In reply to repook from comment #11)
> > (In reply to Lucia Mrenica from comment #10)
> > > Created attachment 183204 [details]
> > > Half green half black
> > > 
> > > I have a similar issue or maybe the same one, when i lock my system (Meta+L)
> > > half of my screen turns green and the other one turns black for like a
> > > second or two before the lock screen screen shows. Is it the same issue as
> > > this one or separate one? I am on Arch Linux everything up to date, amd gpu
> > > laptop. Also there are green glitches in some desktop animations. (Looks the
> > > same, half green half black). Furthermore I've tried killing plasmashell and
> > > if i do that half of my screen turns green and half is black, Spectacle
> > > doesn't capture this only a photo.
> > 
> > Are your graphics integrated? This seems like a visual issue that occurs
> > with Ryzen processors with Vega integrated graphics on Wayland. Specifically
> > when connected to external monitors. This is only speculation because I
> > searched "green" on Reddit and there is 3 posts on the issue with all of
> > them suggesting that they're using Vega (2200g, 3400g, etc). 
> > 
> > I have the same issue with my laptop as well:
> > 
> > Operating System: Fedora Linux 42
> > KDE Plasma Version: 6.4.2
> > KDE Frameworks Version: 6.16.0
> > Qt Version: 6.9.1
> > Kernel Version: 6.15.5-200.fc42.x86_64 (64-bit)
> > Graphics Platform: Wayland
> > Processors: 8 × AMD Ryzen 5 3500U with Radeon Vega Mobile Gfx
> > Memory: 12 GiB of RAM (9.6 GiB usable)
> > Graphics Processor: AMD Radeon Vega 8 Graphics
> 
> Yes I am I have a Ryzen 5 3550H and I am connected to an external monitor.
> Is this an issue with Mesa or the kernel then?

I have no clue, sorry. It could be a Mesa or AMDGPU regression but I'm not technical enough to know how to appropriately report it.
I have tried out other Wayland environments (GNOME, Sway, COSMIC) and it only happens on Plasma. If you run the kwin compositor in a nested instance, the issue is not present, but if you run kwin from the TTY then the issue occurs.