Public bug reported:
1) The release of Ubuntu you are using:
Ubuntu 26.04 LTS
2) The version of the package you are using:
linux-image-7.0.0-38-generic
3) What you expected to happen:
The i915 driver should correctly apply hardware dithering when a 10-bit plane
is requested by Mutter on an 8-bit eDP panel. It must also properly restore the
hardware Gamma LUT and display pipe state upon waking from ACPI sleep states
(both s2idle and S3), displaying normal colors.
4) What happened instead:
Upon cold boot and after resuming from sleep, the screen colors are completely
inverted or heavily posterized.
---
DETAILED ROOT CAUSE & HARDWARE SPECS:
* Machine: Dell Precision 5530
* CPU/GPU: Intel Core i7-8850H (Coffee Lake 3e9b) / Intel UHD 630
* Panel: Internal 1080p eDP panel (Sharp 0x149a)
* Compositor: GNOME on Wayland (Mutter 50.1)
Taking a screenshot (PrtScr) while the screen is physically inverted
yields a PERFECT image with normal colors. This isolates the issue to
the kernel i915 driver failing to push the correct state to the
hardware/panel, while the Wayland compositor renders correctly.
Running `drm_info` reveals that Mutter is successfully requesting and scanning
out a 10-bit primary plane:
Format: XRGB2101010 (0x30335258)
The Sharp 1080p panel is an 8-bit (or 6-bit+FRC) display. The i915
driver accepts the 10-bit commit from Mutter but silently fails to
configure the pipe's hardware dithering or color space conversion
correctly on boot and resume, causing a severe bit-shift that manifests
as color inversion.
Workarounds tested that failed to persist:
- i915.enable_dc=0 and i915.enable_psr=0 (Did not prevent the bug).
- mem_sleep_default=deep (Entered S3 successfully, but inversion still happened
on wake).
- Restricting the connector via `video=eDP-1:bpc=8` in GRUB temporarily forces
Mutter to XRGB8888, but the driver state still desyncs across power cycles.
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: linux-image-7.0.0-38-generic 7.0.0-38.38
ProcVersionSignature: Ubuntu 7.0.0-38.38-generic 7.0.14
Uname: Linux 7.0.0-38-generic x86_64
ApportVersion: 2.34.1-0ubuntu0.1
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: omar-ashraf 5735 F.... wireplumber
/dev/snd/seq: omar-ashraf 5715 F.... pipewire
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Thu Oct 8 12:54:25 2026
InstallationDate: Installed on 2026-04-09 (182 days ago)
InstallationMedia: Ubuntu 24.04.3 LTS "Noble Numbat" - Release amd64
(20250805.1)
Lsusb:
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 27c6:5395 Shenzhen Goodix Technology Co.,Ltd.
Fingerprint Reader
Bus 001 Device 004: ID 0c45:671d Microdia Integrated_Webcam_HD
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
MachineType: Dell Inc. Precision 5530
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-38-generic
root=UUID=f4aac615-68a0-4be5-b90f-363df54a8e8f ro video=eDP-1:bpc=8
mem_sleep_default=deep i915.enable_dc=0 quiet splash i915.enable_psr=0
i915.enable_psr=0 i915.enable_fbc=0
crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
SourcePackage: linux
UpgradeStatus: Upgraded to resolute on 2026-10-02 (6 days ago)
dmi.bios.date: 12/11/2024
dmi.bios.release: 1.42
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.42.0
dmi.board.name: 0NFGCT
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.asset.tag: AI942495
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias:
dmi:bvnDellInc.:bvr1.42.0:bd12/11/2024:br1.42:svnDellInc.:pnPrecision5530:pvr:rvnDellInc.:rn0NFGCT:rvrA00:cvnDellInc.:ct10:cvr:sku087D:pfaPrecision:
dmi.product.family: Precision
dmi.product.name: Precision 5530
dmi.product.sku: 087D
dmi.sys.vendor: Dell Inc.
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
** Attachment added: "preview.webp"
https://bugs.launchpad.net/bugs/2169960/+attachment/6007167/+files/preview.webp
--
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https://bugs.launchpad.net/bugs/2169960
Title:
[i915][CFL] Color inversion on resume/boot with 10-bit primary plane
(Sharp 0x149a eDP)
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