Bug 431890 - Gray panel with 10-bit colours
Summary: Gray panel with 10-bit colours
Status: RESOLVED UNMAINTAINED
Alias: None
Product: kwin
Classification: Plasma
Component: effects-various (show other bugs)
Version: 5.20.5
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-01-21 19:40 UTC by bethock
Modified: 2023-09-06 10:13 UTC (History)
2 users (show)

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


Attachments
Comparison of Firefox and Chromium (232.83 KB, image/png)
2021-01-21 19:40 UTC, bethock
Details
Broken "Desktop effects" tab (129.64 KB, image/png)
2021-01-22 16:25 UTC, bethock
Details
The same problem with Application Launcher (64.24 KB, image/png)
2021-01-23 09:03 UTC, bethock
Details

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Description bethock 2021-01-21 19:40:47 UTC
Created attachment 135037 [details]
Comparison of Firefox and Chromium

SUMMARY
When I activate 10-bit colours with "DefaultDepth 30" in xorg.conf I have broken colour of the plasma panel. The same problem with Chromium. I attached the screenshot with Chromium and Firefox comparison. The same problem with the plasma panel, it's much darker than it was with 8-bit colours. I checked, 10-bit colours output works fine for a test picture.
If I switch the rendering backend from OpenGL 3.1 to XRender, the panel looks good, but the windows title breaks (become pink).
How to diagnose this problem? How the problem with chromium can be associated with plasma?

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: ArchLinux 5.10.9-arch1-1
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2
Nvidia driver version: 460.32.03
X Server Vendor Version: 1.20.10 (12010000)
Current Global Theme: Breeze

ADDITIONAL INFORMATION
Video card: Nvidia 1050 Ti
Monitor: BenQ EW3280U (4k, 8bit + FRC, 60Hz), connected with DP 1.4 cable
Motherboard: ASUS TUG-Gaming X570
CPU: Ryzen 3950X
Comment 1 Nate Graham 2021-01-22 14:41:33 UTC
Looks to me like the "Background Contrast" KWin effect isn't working properly. Can you try toggling it off and on again in System Settings > Workspace Behavior > Desktop Effects? Make sure to hit Apply after turning it off and also after turning it back on.
Comment 2 bethock 2021-01-22 16:23:58 UTC
After turning off "Background Contrast" effect, the panel looks good, but not Chromium. Can we diagnose the problem with "Background Contrast" effect?

Also, there is a strange thing in "Workspace behaviour" tab: there are two "Desktop effects" tabs. Take a look at the attached screenshot. Should I create  a separate bug report?
Comment 3 bethock 2021-01-22 16:25:00 UTC
Created attachment 135062 [details]
Broken "Desktop effects" tab
Comment 4 Nate Graham 2021-01-22 21:09:39 UTC
That's a packaging issue and not related to this.

*** This bug has been marked as a duplicate of bug 423297 ***
Comment 5 bethock 2021-01-23 09:03:02 UTC
Created attachment 135089 [details]
The same problem with Application Launcher
Comment 6 bethock 2021-01-23 09:17:09 UTC
xprop output for the broken panel:
_KDE_NET_WM_SHADOW(CARDINAL) = 29360607, 29360609, 29360609, 29360609, 29360609, 29360609, 29360609, 29360609, 6, 1, 1, 1
_KDE_NET_WM_ACTIVITIES(STRING) = "00000000-0000-0000-0000-000000000000"
_NET_WM_ALLOWED_ACTIONS(ATOM) = _NET_WM_ACTION_CHANGE_DESKTOP
WM_STATE(WM_STATE):
                window state: Normal
                icon window: 0x0
_NET_WM_STATE(ATOM) = 
_NET_WM_STRUT(CARDINAL) = 0, 0, 0, 50
_NET_WM_STRUT_PARTIAL(CARDINAL) = 0, 0, 0, 50, 0, 0, 0, 0, 0, 0, 0, 3839
_NET_WM_USER_TIME(CARDINAL) = 2852043
_KDE_SLIDE(_KDE_SLIDE) = 0xffffffff, 0x3
_NET_WM_DESKTOP(CARDINAL) = 4294967295
_KDE_NET_WM_BACKGROUND_CONTRAST_REGION(_KDE_NET_WM_BACKGROUND_CONTRAST_REGION) = 0x0, 0x0, 0xf00, 0x32, 0x3f16e617, 0xbd67a2a7, 0xbd67a2a7, 0x0, 0xbe42cf1c, 0x3ee958f5, 0xbe42cf1c, 0x0, 0xbc9d543a, 0xbc9d543a, 0x3f2075a0, 0x0, 0x3f428f5d, 0x3f428f5d, 0x3f428f5d, 0x3f800000
_KDE_NET_WM_BLUR_BEHIND_REGION(CARDINAL) = 0, 0, 3840, 50
_KDE_NET_WM_DESKTOP_FILE(UTF8_STRING) = "org.kde.plasmashell"
XdndAware(ATOM) = BITMAP
_KDE_NET_WM_USER_CREATION_TIME(CARDINAL) = 23360
WM_NAME(STRING) = 
_NET_WM_NAME(UTF8_STRING) = "Plasma"
_MOTIF_WM_HINTS(_MOTIF_WM_HINTS) = 0x2, 0x1, 0x0, 0x0, 0x0
_NET_WM_WINDOW_TYPE(ATOM) = _NET_WM_WINDOW_TYPE_DOCK, _KDE_NET_WM_WINDOW_TYPE_OVERRIDE, _NET_WM_WINDOW_TYPE_NORMAL
_XEMBED_INFO(_XEMBED_INFO) = 0x0, 0x1
WM_CLIENT_LEADER(WINDOW): window id # 0x1c00010
WM_HINTS(WM_HINTS):
                Client accepts input or input focus: False
                window id # of group leader: 0x1c00010
WM_CLIENT_MACHINE(STRING) = "a"
_NET_WM_PID(CARDINAL) = 1397
_NET_WM_SYNC_REQUEST_COUNTER(CARDINAL) = 29360157
WM_CLASS(STRING) = "plasmashell", "plasmashell"
WM_PROTOCOLS(ATOM): protocols  WM_DELETE_WINDOW, WM_TAKE_FOCUS, _NET_WM_PING, _NET_WM_SYNC_REQUEST
WM_NORMAL_HINTS(WM_SIZE_HINTS):
                user specified location: 0, 2110
                user specified size: 3840 by 50
                program specified minimum size: 3840 by 50
                program specified maximum size: 3840 by 50
                window gravity: Static
Comment 7 bethock 2021-01-23 09:31:46 UTC
Tell me what information I can provide more to find out the cause of this problem. Maybe some logs or I can debug it if you hint me what to check.
Comment 8 Nate Graham 2021-01-25 16:16:04 UTC
Re-opening as apparently I marked this as a duplicate of Bug 423297 in error.

Moving to KWin as it seems like a rendering issue with the Background Contrast effect.
Comment 9 Zamundaaa 2023-09-06 10:13:40 UTC
Too many things break with 10 bit colors on Xorg, so we won't support it going forward. If you want 10 bit colors, you need to use Wayland