Bug 488189

Summary:	Regression: wrong position of top-panel of the primary screen in a multi-screen setup with mixed resolution monitors
Product:	[Plasma] kwin	Reporter:	goo
Component:	multi-screen	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED FIXED
Severity:	major	CC:	nate
Priority:	NOR	Keywords:	multiscreen
Version First Reported In:	6.0.5
Target Milestone:	---
Platform:	Fedora RPMs
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:	6.1.0
Sentry Crash Report:
Attachments:	mixed resolutions multi-monitor setup

Description goo 2024-06-08 01:03:35 UTC

SUMMARY
Runing KDE Plasma on X11. I have a four monitor setup.
After upgrading to Plasma Frameworks 6.3 my multi-monitor setup gone nuts. After resuming from monitor standby, all the monitors suddenly got shrunked to 1280x1024. After rearranging all the monitors to my usual setup, the top panel of my primary QHD monitor has been repositioned down as if it was at the top of the left FHD monitor. Also windows can't be moved to the top of the primary QHD monitor (see attachment).
Had to downgrade to Frameworks 6.2. This is very frustrating as multi-monitor setup did never work properly like it did in 5.27. Indeed since 6.0 two of my four monitors occasionally don't come back from standby but this is way worse.

STEPS TO REPRODUCE
1. upgrade to Plasma Frameworks 6.3
2. wait for your monitors to go in standby
3. resume from monitor standby

OBSERVED RESULT
All the monitors suddenly go to 1280x1024. This happened a bunch of times. Then after session logout and logging back in, after trying to rearrange the monitors to the inititial setup, the top panel of my primary QHD monitor has been repositioned like if it was at the top of the leftmost FHD monitor. Also windows can't be moved at the top of the primary QHD monitor. Then the next standby/resume iterations didn't trigger the reset to 1280x1024 like it happend initially.

EXPECTED RESULT
The top panel of the primary QHD monitor should stay at the top of the display and not as if it was at the top of the leftmost FHD monitor.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 40
KDE Plasma Version: 6.0.5
KDE Frameworks Version: 6.3
Qt Version: 6.7

ADDITIONAL INFORMATION

$ kscreen-doctor -i -o
Environment:
* KSCREEN_BACKEND           : [not set]
* KSCREEN_BACKEND_INPROCESS : [not set]
* KSCREEN_LOGGING           : [not set]
Logging to                : [logging disabled]
Preferred KScreen backend : KSC_XRandR.so
Available KScreen backends:
* KSC_Fake.so: /usr/lib64/qt6/plugins/kf6/kscreen/KSC_Fake.so
* KSC_KWayland.so: /usr/lib64/qt6/plugins/kf6/kscreen/KSC_KWayland.so
* KSC_QScreen.so: /usr/lib64/qt6/plugins/kf6/kscreen/KSC_QScreen.so
* KSC_XRandR.so: /usr/lib64/qt6/plugins/kf6/kscreen/KSC_XRandR.so

Output: 85 DisplayPort-0
enabled
connected
priority 1
DisplayPort
Modes:  91:2560x1440@60*!  92:2560x1440@75  93:2560x1440@72  94:2560x1440@60  95:2560x1440@50  96:2560x1440@48  97:1920x1200@60  98:1920x1080@75  99:1920x1080@60  100:1920x1080@50  101:1920x1080@60  102:1600x1200@60  103:1280x1440@60  104:1680x1050@60  105:1280x1024@75  106:1280x1024@60  107:1440x900@60  108:1280x960@60  109:1280x800@60  110:1280x720@60  111:1280x720@50  112:1280x720@60  113:1024x768@75  114:1024x768@70  115:1024x768@60  116:832x624@75  117:800x600@72  118:800x600@75  119:800x600@60  120:800x600@56  121:720x576@50  122:720x480@60  123:720x480@60  124:640x480@75  125:640x480@73  126:640x480@67  127:640x480@60  128:640x480@60  129:720x400@70
Geometry: 1920,844 2560x1440
Scale: 1
Rotation: 1
Overscan: 0
Vrr: incapable
RgbRange: unknown
HDR: incapable
Wide Color Gamut: incapable
ICC profile: incapable
Output: 86 DisplayPort-1
disabled
disconnected
priority 0
DisplayPort
Modes:
Geometry: 0,0 0x0
Scale: 1
Rotation: 1
Overscan: 0
Vrr: incapable
RgbRange: unknown
HDR: incapable
Wide Color Gamut: incapable
ICC profile: incapable
Output: 87 HDMI-A-0
enabled
connected
priority 2
HDMI
Modes:  105:1280x1024@75*  106:1280x1024@60!  113:1024x768@75  114:1024x768@70  115:1024x768@60  116:832x624@75  117:800x600@72  118:800x600@75  119:800x600@60  120:800x600@56  124:640x480@75  125:640x480@73  126:640x480@67  128:640x480@60  129:720x400@70  130:1280x800@60  131:1152x864@75  132:1280x720@60
Geometry: 640,0 1280x1024
Scale: 1
Rotation: 4
Overscan: 0
Vrr: incapable
RgbRange: unknown
HDR: incapable
Wide Color Gamut: incapable
ICC profile: incapable
Output: 88 HDMI-A-1
enabled
connected
priority 4
HDMI
Modes:  99:1920x1080@60!  100:1920x1080@50  101:1920x1080@60*  106:1280x1024@60  110:1280x720@60  111:1280x720@50  112:1280x720@60  115:1024x768@60  119:800x600@60  121:720x576@50  122:720x480@60  123:720x480@60  127:640x480@60  128:640x480@60 133:1920x1080@50  134:1680x1050@60  135:1600x900@60  136:1440x900@60  137:1280x800@60
Geometry: 4480,364 1080x1920
Scale: 1
Rotation: 2
Overscan: 0
Vrr: incapable
RgbRange: unknown
HDR: incapable
Wide Color Gamut: incapable
ICC profile: incapable
Output: 89 DVI-D-0
enabled
connected
priority 3
DVI
Modes:  99:1920x1080@60*!  106:1280x1024@60  108:1280x960@60  115:1024x768@60  119:800x600@60  128:640x480@60  134:1680x1050@60  138:1440x900@60  139:1280x800@60  140:1152x864@60  141:1280x720@60
Geometry: 0,1024 1920x1080
Scale: 1
Rotation: 1
Overscan: 0
Vrr: incapable
RgbRange: unknown
HDR: incapable
Wide Color Gamut: incapable
ICC profile: incapable

Comment 1 goo 2024-06-08 01:12:10 UTC

Created attachment 170245 [details]
mixed resolutions multi-monitor setup

Comment 2 goo 2024-06-08 01:42:23 UTC

Given another try with KF6.3. After entering panel edit mode and moving the panel to the bottom position and then back to the top position it positioned at the top of the QHD display as it should. It seems work properly now. Let's see how it goes in the next couple of days and if it'll ever trigger again a multi-screen disposition reset while using it.

Comment 3 Nate Graham 2024-06-10 19:49:29 UTC

I'm not seeing any commits in the full list available at https://kde.org/announcements/frameworks/6/6.3.0 that I think could explain this, so it's possible other updates may have regressed things--especially if there were any kernel updates.

Regardless, the issue with monitors switching resolution inappropriately should be fixed in Plasma 6.1, which is scheduled to be released in about a week. I'm going to close this for now, but feel free to re-open this bugzilla ticket *if you still experience the issue of monitors having the wrong resolution* in Plasma 6.1. If that gets fixed by the panel is still in the wrong place. Please open a new bug report for that.

Thanks a lot!