[Bug 2163204] Re: Regression: Acer Nitro AN515-55 internal eDP display/backlight fails to resume from S3 since 7.0.0-28; 7.0.0-27 works

*** This bug is a duplicate of bug 2161309 *** https://bugs.launchpad.net/bugs/2161309 ** This bug has been marked a duplicate of bug 2161309 Backlight regression -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2163204 Title: Regression: Acer Nitro AN515-55 internal eDP display/backlight fails to resume from S3 since 7.0.0-28; 7.0.0-27 works Status in linux package in Ubuntu: New Bug description: After upgrading the Ubuntu 26.04 kernel from 7.0.0-27-generic to 7.0.0-28-generic, my Acer Nitro AN515-55 no longer restores the internal display after suspend-to-RAM (S3/deep). The problem is also present in 7.0.0-29-generic. The computer itself successfully resumes. I can connect to the machine over SSH after the failed resume, networking works, and kernel logs reach PM: suspend exit. The failure appears limited to restoration of the internal Intel-driven eDP display/backlight. Regression testing: 7.0.0-27-generic: WORKS 7.0.0-28-generic: FAILS 7.0.0-29-generic: FAILS I tested 7.0.0-27 with the same NVIDIA 595.84 open driver currently used on the newer kernels, and suspend/resume works normally. Hardware: Acer Nitro AN515-55 Intel CometLake-H GT2 UHD Graphics (i915) NVIDIA GeForce RTX 3050 Mobile Internal 1920x1080 eDP panel BIOS V2.06 Failure behavior: Boot 7.0.0-28 or 7.0.0-29. Suspend using systemctl suspend or normal desktop suspend. Wake the computer. Computer resumes and remains accessible via SSH, but the internal laptop display remains completely black. During the failed state: /sys/class/drm/card1-eDP-1/status reports connected. i915_display_info reports Pipe A enabled and active and eDP-1 connected. The framebuffer is reported visible. /sys/class/backlight/intel_backlight/brightness accepts nonzero values. /sys/class/backlight/intel_backlight/actual_brightness remains 0. Writing brightness values manually does not restore the display. Switching virtual terminals does not restore it. Restarting GDM does not restore it. Additional testing performed: pm_test=devices: passes pm_test=platform: passes pm_test=core: passes PRIME Intel-only mode: still fails on affected kernels i915.enable_psr=0: no change intel_iommu=off: no change pcie_aspm=off: no fix 60 Hz instead of 144 Hz: no change s2idle: does not behave correctly on this hardware S3/deep is the normal sleep mode (s2idle [deep]) The regression therefore appears to have been introduced between Ubuntu kernels 7.0.0-27 and 7.0.0-28, possibly affecting restoration of the Intel i915/eDP panel or backlight following a real S3 transition. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-29-generic 7.0.0-29.29 ProcVersionSignature: Ubuntu 7.0.0-29.29-generic 7.0.12 Uname: Linux 7.0.0-29-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: leo 3546 F.... wireplumber /dev/snd/controlC1: leo 3546 F.... wireplumber /dev/snd/seq: leo 3525 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Mon Aug 10 15:02:21 2026 InstallationDate: Installed on 2025-10-13 (301 days ago) InstallationMedia: Ubuntu 24.04.2 LTS "Noble Numbat" - Release amd64 (20250215) Lsusb: Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 1ea7:0064 SHARKOON Technologies GmbH 2.4GHz Wireless rechargeable vertical mouse [More&Better] Bus 001 Device 003: ID 04f2:b64f Chicony Electronics Co., Ltd HD User Facing Bus 001 Device 004: ID 8087:0026 Intel Corp. AX201 Bluetooth Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub MachineType: Acer Nitro AN515-55 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-7.0.0-29-generic root=UUID=21d24b70-7c3c-4b62-8c0c-b0018d627618 ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 08/20/2021 dmi.bios.release: 2.6 dmi.bios.vendor: Insyde Corp. dmi.bios.version: V2.06 dmi.board.asset.tag: Type2 - Board Asset Tag dmi.board.name: Stonic_CMS dmi.board.vendor: CML dmi.board.version: V2.06 dmi.chassis.type: 10 dmi.chassis.vendor: Acer dmi.chassis.version: V2.06 dmi.ec.firmware.release: 2.5 dmi.modalias: dmi:bvnInsydeCorp.:bvrV2.06:bd08/20/2021:br2.6:efr2.5:svnAcer:pnNitroAN515-55:pvrV2.06:rvnCML:rnStonic_CMS:rvrV2.06:cvnAcer:ct10:cvrV2.06:sku0000000000000000:pfaNitro5: dmi.product.family: Nitro 5 dmi.product.name: Nitro AN515-55 dmi.product.sku: 0000000000000000 dmi.product.version: V2.06 dmi.sys.vendor: Acer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2163204/+subscriptions