Public bug reported:
**Source package:** linux
**Ubuntu release:**
Ubuntu 24.04.4 LTS
**Affected kernel package/version:**
linux-image-7.0.0-28-generic
**Hardware:**
Dell G5 laptop with:
* Intel CoffeeLake-H GT2 / UHD Graphics 630
* Intel `i915` kernel driver
* NVIDIA GeForce GTX 1650 Mobile using the proprietary `nvidia` driver
* Internal eDP laptop display
* External monitor connected through HDMI
**Problem description**
After updating Ubuntu and booting kernel `7.0.0-28-generic`, the
internal laptop display becomes extremely dim. The backlight is not
completely off, but even at maximum brightness the display remains
barely usable. The external HDMI monitor has normal brightness and is
unaffected. The screen has normal brightness during the pre-boot disk-
encryption password prompt. It becomes dark when Ubuntu starts loading
the graphical system. The Ubuntu login screen, GNOME desktop, and text
virtual consoles are all affected. The keyboard brightness controls
still change the brightness slightly, but only across a range from
“very, very dark” to “very dark.”
**Expected result**
The internal laptop display should retain normal brightness after Ubuntu
starts, and setting the brightness to maximum should produce normal full
brightness.
**Actual result**
Under kernel `7.0.0-28-generic`, the internal display remains extremely
dim even when Ubuntu reports the backlight as being at its maximum
value.
The following values are reported:
```text
$ cat /sys/class/backlight/intel_backlight/brightness
1023
$ cat /sys/class/backlight/intel_backlight/actual_brightness
1023
$ cat /sys/class/backlight/intel_backlight/max_brightness
1023
```
The backlight interface reports:
```text
$ cat /sys/class/backlight/intel_backlight/scale
unknown
$ cat /sys/class/backlight/intel_backlight/type
raw
$ cat /sys/class/backlight/intel_backlight/bl_power
0
```
Manually lowering and restoring the brightness does not fix the problem:
```bash
echo 100 | sudo tee /sys/class/backlight/intel_backlight/brightness
echo 1023 | sudo tee /sys/class/backlight/intel_backlight/brightness
```
**Regression test**
The problem occurs with 7.0.0-28-generic. The problem does not occur
with 6.17.0-35-generic. Booting `6.17.0-35-generic` restores normal
internal-display brightness immediately. No other configuration changes
are required. This appears to be a kernel regression, likely involving
the Intel `i915` driver or its control of the internal eDP panel
backlight.
**Graphics hardware and drivers**
```text
00:02.0 VGA compatible controller: Intel Corporation CoffeeLake-H GT2 [UHD
Graphics 630]
DeviceName: Onboard - Video
Subsystem: Dell CoffeeLake-H GT2 [UHD Graphics 630]
Kernel driver in use: i915
01:00.0 VGA compatible controller: NVIDIA Corporation TU117M [GeForce GTX 1650
Mobile / Max-Q] (rev a1)
Subsystem: Dell TU117M [GeForce GTX 1650 Mobile / Max-Q]
Kernel driver in use: nvidia
Kernel modules: nvidiafb, nouveau, nvidia_drm, nvidia
```
**Kernel command line**
```text
BOOT_IMAGE=/vmlinuz-7.0.0-28-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro
quiet splash vt.handoff=7
```
**Additional observations**
* The internal display is normally bright before Ubuntu loads, including at the
disk-encryption password prompt.
* The Ubuntu login screen is dark.
* The GNOME desktop is dark.
* A text console reached with `Ctrl+Alt+F3` is also dark.
* The HDMI monitor remains normal.
* Only `intel_backlight` appears under `/sys/class/backlight/`.
* No `panel_power_savings` entry exists under `/sys/class/drm/`.
* Booting the older kernel reliably resolves the problem.
ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: linux-image-7.0.0-28-generic 7.0.0-28.28~24.04.1
ProcVersionSignature: Ubuntu 7.0.0-28.28~24.04.1-generic 7.0.12
Uname: Linux 7.0.0-28-generic x86_64
ApportVersion: 2.28.2-0ubuntu0.1
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: leon 3118 F.... wireplumber
/dev/snd/controlC0: leon 3118 F.... wireplumber
/dev/snd/seq: leon 3114 F.... pipewire
CRDA: N/A
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Fri Jul 17 17:44:11 2026
InstallationDate: Installed on 2026-02-26 (141 days ago)
InstallationMedia: Ubuntu 24.04.4 LTS "Noble Numbat" - Release amd64 (20260210)
MachineType: Dell Inc. G5 5590
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
ProcFB:
0 i915drmfb
1 nvidia-drmdrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-28-generic
root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash vt.handoff=7
RelatedPackageVersions:
linux-restricted-modules-7.0.0-28-generic N/A
linux-backports-modules-7.0.0-28-generic N/A
linux-firmware 20240318.git3b128b60-0ubuntu2.27
SourcePackage: linux-hwe-7.0
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/20/2020
dmi.bios.release: 1.14
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.14.0
dmi.board.name: 0C32VF
dmi.board.vendor: Dell Inc.
dmi.board.version: A01
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias:
dmi:bvnDellInc.:bvr1.14.0:bd10/20/2020:br1.14:svnDellInc.:pnG55590:pvr:rvnDellInc.:rn0C32VF:rvrA01:cvnDellInc.:ct10:cvr:sku08EA:pfaGSeries:
dmi.product.family: GSeries
dmi.product.name: G5 5590
dmi.product.sku: 08EA
dmi.sys.vendor: Dell Inc.
** Affects: linux-hwe-7.0 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug noble
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https://bugs.launchpad.net/bugs/2161153
Title:
Internal display backlight extremely dim with 7.0.0-28-generic on Dell
G5, works with 6.17.0-35
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