Bug 506254

Summary: Native panel resolution refused on (external) screen
Product: [Plasma] KScreen Reporter: André Hübert Johansen <andrejoh>
Component: commonAssignee: kscreen-bugs-null <kscreen-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal CC: xaver.hugl
Priority: NOR    
Version First Reported In: 6.4.1   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Output from kscreen-doctor
System settings display configuration

Description André Hübert Johansen 2025-06-27 06:54:52 UTC
Created attachment 182717 [details]
Output from kscreen-doctor

SUMMARY
On a laptop with two 2560x1600 external screens, the resolution of one of the screens is refused applied, 1920x1200 works.

STEPS TO REPRODUCE
1. Use the display configuration in system settings to configure order and resolution of screens.
2. When applying, the message "Couldn’t apply display configuration: The driver rejected the output configuration" appears; correct resolution is not applied.

OBSERVED RESULT
Resolutions of 1920x1200 or lower are accepted, the native resolution not.

EXPECTED RESULT
Native resolution applied.

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 42
KDE Plasma Version: 6.4.1
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1
Kernel Version: 6.13.12-200.fc41.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i7-6600U CPU @ 2.60GHz
Memory: 16 GiB of RAM (15.4 GiB usable)
Graphics Processor: Intel® HD Graphics 520


ADDITIONAL INFORMATION
This worked correctly with Plasma versions through 6.3; after an update to 6.4.0, this bug appeared - and is also present in 6.4.1.
Tried with different Linux kernels; same problem with 6.13.12, 6.14.x (various) and 6.15.3.

Attempting to set the native resolution using kscreen-doctor gives a similar error message:

$ kscreen-doctor output.DP-4.mode.45
applying config failed! The driver rejected the output configuration
Comment 1 André Hübert Johansen 2025-06-27 06:56:09 UTC
Created attachment 182718 [details]
System settings display configuration
Comment 2 André Hübert Johansen 2025-07-14 16:06:39 UTC
After an upgrade today, which included KDE Frameworks 6.16.0, the problem is gone.  Logged out after the upgrade, the screen could be set to native resolution when logging in again.
Comment 3 André Hübert Johansen 2025-08-01 20:52:58 UTC
After an update to KDE Plasma 6.4.3 today, the problem is back, but on a different screen (the leftmost in the configuration).
Comment 4 Zamundaaa 2025-10-14 16:01:42 UTC
Please report this at https://gitlab.freedesktop.org/drm/i915/kernel/-/issues - if the driver rejects the output config, there's nothing more we can do about it.