https://bugs.kde.org/show_bug.cgi?id=517175
Bug ID: 517175
Summary: LG OLED TV Loses EDID on Power Cycle
Classification: Plasma
Product: KScreen
Version First 5.18.0
Reported In:
Platform: CachyOS
OS: Linux
Status: REPORTED
Severity: normal
Priority: NOR
Component: common
Assignee: [email protected]
Reporter: [email protected]
Target Milestone: ---
Just to preface this bug report, this is an issue i've had for quite some time,
it's been hard to find work arounds for, this report is generated by claude,
but carefully reviewed to the best of my ability (fairly limited when it comes
to linux specifics). claude had full context of the issue, with all the
debugging. I made sure it knew which versions everything was.
SUMMARY
LG OLED TV loses EDID on power cycle, display falls back to 1024x768 with no
HDR or native modes
STEPS TO REPRODUCE
1. Connect LG OLED TV via HDMI, boot system with TV powered on
2. Confirm display is working at 3840x2160 @ 120Hz with HDR
3. Power off the TV using its remote or power button
4. Wait a few minutes (it has a soft sleep, then full sleep, you can tell when
it's fully waking up because you can hear a click when the power goes to the TV
(mosfet? idk)
5. Power the TV back on
OBSERVED RESULT
Display falls back to 1024x768 @ 60Hz. kscreen-doctor reports HDR: incapable
and Wide Color Gamut: incapable. Only 5 basic VESA modes are available. The
EDID is completely empty at the kernel level (cat
/sys/class/drm/card1-HDMI-A-1/edid | wc -c returns 0) even though the connector
reports "connected". nvidia-xconfig --query-gpu-info confirms "No EDID
information available." The display remains broken until the compositor is
restarted with kwin_wayland --replace, which crashes all running applications.
EXPECTED RESULT
Display should restore to its native resolution and capabilities (3840x2160 @
120Hz, HDR, Wide Color Gamut) when the TV powers back on, without user
intervention.
SOFTWARE/OS VERSIONS
Linux/KDE Plasma: CachyOS Linux (also reproduced on Bazzite)
KDE Plasma Version: 6.6.1
KDE Frameworks Version: 6.23.0
Qt Version: 6.10.2
Kernel Version: 6.19.5-3-cachyos (64-bit)
Graphics Platform: Wayland
Graphics Processor: NVIDIA GeForce RTX 3090 Ti (proprietary driver, nvidia_drm)
ADDITIONAL INFORMATION
The root cause is that LG OLED TVs briefly stop broadcasting EDID during their
power-on sequence. Nvidia's proprietary DRM implementation does not expose a
force sysfs file (unlike amdgpu/i915), so there is no way to trigger a hotplug
re-detection without restarting the compositor.
Workaround: capture the EDID while the display is working and configure the
Nvidia driver to use the stored copy permanently:
sudo mkdir -p /lib/firmware/edid
sudo cp /sys/class/drm/card1-HDMI-A-1/edid /lib/firmware/edid/lg-oled.bin
Then create /etc/X11/xorg.conf.d/10-nvidia-edid.conf:
Section "Device"
Identifier "NVIDIA GPU"
Driver "nvidia"
Option "ConnectedMonitor" "HDMI-A-1"
Option "CustomEDID" "HDMI-A-1:/lib/firmware/edid/lg-oled.bin"
EndSection
This issue likely affects a large number of users as LG OLED TVs are very
common in PC gaming setups.
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