Public bug reported:
Dell Latitude 7320 on Ubuntu: screen becomes very dim after boot/login.
BIOS is normal; intel_backlight reports near-max brightness. Fixed by
adding i915.enable_dpcd_backlight=0 to GRUB kernel parameters.
On a Dell Latitude 7320, the screen is bright in BIOS and during the
Ubuntu splash, then becomes very dim right before/after login.
intel_backlight reports near-max brightness, but the panel is still hard
to see. The issue is fixed by adding i915.enable_dpcd_backlight=0 to the
kernel command line.
Steps to reproduce:
Boot Ubuntu on Dell Latitude 7320.
Observe bright BIOS/logo screen.
After the Ubuntu splash/desktop starts, the panel dims heavily.
Expected:
Brightness should stay normal.
Actual:
Panel becomes very dim despite brightness showing near maximum.
Workaround/Fix:
Add i915.enable_dpcd_backlight=0 to GRUB kernel parameters.
Notes:
intel_backlight shows max/near-max values.
BIOS screen is normal, so it doesn’t appear to be hardware brightness.
xrandr showed Brightness: 0.0 at one point, but resetting it did not fix
the issue.
psr and dc were already disabled.
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/controlC0: iandi 3469 F.... wireplumber
/dev/snd/seq: iandi 3464 F.... pipewire
CRDA: N/A
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Sat Jul 18 14:24:46 2026
InstallationDate: Installed on 2025-06-01 (412 days ago)
InstallationMedia: Ubuntu 24.04.1 LTS "Noble Numbat" - Release amd64
(20240827.1)
MachineType: Dell Inc. Latitude 7320
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-7.0.0-28-generic
root=UUID=52f21745-a88b-4357-8cfe-3292dff67d96 ro quiet splash
i915.enable_dpcd_backlight=0 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: 04/23/2026
dmi.bios.release: 1.50
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.50.1
dmi.board.name: 07MHG4
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias:
dmi:bvnDellInc.:bvr1.50.1:bd04/23/2026:br1.50:svnDellInc.:pnLatitude7320:pvr:rvnDellInc.:rn07MHG4:rvrA00:cvnDellInc.:ct10:cvr:sku0A34:pfaLatitude:
dmi.product.family: Latitude
dmi.product.name: Latitude 7320
dmi.product.sku: 0A34
dmi.sys.vendor: Dell Inc.
** Affects: linux-hwe-7.0 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug noble wayland-session
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https://bugs.launchpad.net/bugs/2161216
Title:
screen becomes very dim after boot/login
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