[Bug 2161928] Re: Kernel regression: internal display becomes abnormally dim with 7.0.0-28

*** This bug is a duplicate of bug 2161182 *** https://bugs.launchpad.net/bugs/2161182 Since this bug was reported. BIOS on laptop was upgraded to 1.44. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2161928 Title: Kernel regression: internal display becomes abnormally dim with 7.0.0-28 Status in linux package in Ubuntu: New Bug description: **Kernel regression: internal display becomes abnormally dim with 7.0.0-28** On my Dell Latitude 7390 running Ubuntu Cinnamon 26.04, the internal laptop display becomes abnormally dim when booted with Linux kernel 7.0.0-28-generic. The problem started immediately after upgrading from kernel 7.0.0-27 to 7.0.0-28. I tested both kernels on the same computer: * 7.0.0-28-generic: internal display is abnormally dim. * 7.0.0-27-generic: display brightness is normal. Booting 7.0.0-27 immediately restores normal display brightness. There is no external monitor connected. The problem affects only the built-in laptop display. This appears to be a kernel regression introduced in 7.0.0-28. Please investigate possible changes to the Intel i915 DRM/display/backlight subsystem. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-27-generic 7.0.0-27.27 ProcVersionSignature: Ubuntu 7.0.0-27.27-generic 7.0.6 Uname: Linux 7.0.0-27-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: user-meir 3893 F.... pipewire user-meir 3897 F.... wireplumber /dev/snd/pcmC0D0p: user-meir 3893 F...m pipewire /dev/snd/seq: user-meir 3893 F.... pipewire CasperMD5CheckResult: unknown CurrentDesktop: X-Cinnamon Date: Mon Jul 27 15:07:58 2026 Lsusb: Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 0bda:58ca Realtek Semiconductor Corp. Integrated_Webcam_HD Bus 001 Device 003: ID 8087:0032 Intel Corp. AX210 Bluetooth Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub MachineType: Dell Inc. Latitude 7390 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-7.0.0-27-generic root=UUID=f1f51d68-fa8a-4c38-b218-a14509b07bc9 ro quiet splash SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) WifiSyslog: dmi.bios.date: 11/06/2024 dmi.bios.release: 1.41 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.41.0 dmi.board.vendor: Dell Inc. dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.41.0:bd11/06/2024:br1.41:svnDellInc.:pnLatitude7390:pvr:rvnDellInc.:rn:rvr:cvnDellInc.:ct10:cvr:sku081B:pfaLatitude: dmi.product.family: Latitude dmi.product.name: Latitude 7390 dmi.product.sku: 081B dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161928/+subscriptions