[Bug 2150769] Re: pc-kernel snaps are missing some intel firmware but it also cannot be installed by users manually

I also created a fix and set up a merge request for it, but it's a bit brute-force and just copies every iwlwifi firmware image into the snap (since there's no practical way to know which one the device silicon is going to ask for). -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2150769 Title: pc-kernel snaps are missing some intel firmware but it also cannot be installed by users manually Status in canonical-kernel-snaps: Confirmed Status in boot-managed-by-snapd package in Ubuntu: New Status in linux package in Ubuntu: Invalid Status in linux-firmware-intel-wireless package in Ubuntu: Invalid Bug description: I described in detail here, in case I miss anything in this description: https://discourse.ubuntu.com/t/the-pc-kernel-snap- on-26-04-prevents-users-from-installing-additional-firmware/81404 This bug report is pretty wordy so here's a top-line summary: 1. The pc-kernel snap uses an unfortunately unreliable method of including firmware, which means some firmware gets missed 2. The apt dependencies of `boot-managed-by-snapd` preclude installing `linux-firmware` but do not preclude installing any other firmware packages making it possible to break your system in a pretty dramatic way that many users might have a very difficult time figuring out or resolving. Reproduction steps: 1. Install Ubuntu using the `pc-kernel` snap rather than apt kernel packages 2. Install the `linux-firmware-intel-wireless` package Okay, now on to the verbose part of the bug report which I hope is at least partially understandable. Circumstance: 1. I'm running Ubuntu 26.04 using the pc-kernel snapo (because of hardware FDE I guess) 2. My laptop has a pretty new Arrow Lake chipset with an Intel wifi adapter 3. My wifi doesn't work What I discovered while debugging: the `iwlwifi` module won't load properly because it can't find the firmware file it wants, as it is not present in the `pc-kernel` snap, so wifi doesn't work. This took me in a few different directions and this is what I found: * Unspecified incompatibility between pc-kernel and additional firmware packages First, the pc-kernel snap creates symlinks to everything in its 'firmware' directory into the filesystem that gets mounted at /usr/lib/firmware, but it links everything at the top-level. That means firmware can be added to e.g. /usr/lib/firmware/somefile.fw, because that's a directory, but not /usr/lib/firmware/intel/somefile.fw because /usr/lib/firmware/intel is a symlink to a directory on the squashfs filesystem. This means that installing the `linux-firmware-intel-wireless` package, which has the firmware I need: 1. Breaks when trying to install because it tries to write some files to /usr/lib/firmware/intel/ 2. Refuses to uninstall until it's installed correctly, because dpkg recognizes it as being in an extremely broken state. I say 'unspecified' because `boot-managed-by-snapd` explicitly conflicts with `linux-firmware` (showing the intention to not allow both at once), but it does not conflict with any additional firmware packages. * Incomplete firmware inventory in the pc-kernel snap I dug into it a bit and found that the pc-kernel snap builds using the following steps: 1. Get the kernel and the modules together 2. Ask each module what firmware it wants (via `modinfo`) 3. Bundle those firmwares into the pc-kernel snap Unfortunately, for whatever reason, the `iwlwifi` firmware does not specify the firmware that my system seems to insist on, which is `bz-b0-fm-c0-c101.ucode`, so it does not get included into the pc- kernel snap. The `linux-firmware-intel-wireless` debian package *does* include this firmware, presumably because it just includes all available Intel wireless firmware unconditionally. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-14-generic (not installed) ProcVersionSignature: Ubuntu 7.0.0-14.14-generic 7.0.0 Uname: Linux 7.0.0-14-generic x86_64 ApportVersion: 2.34.0-0ubuntu2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC2: dan 6392 F.... wireplumber /dev/snd/controlC1: dan 6392 F.... wireplumber /dev/snd/controlC0: dan 6392 F.... wireplumber /dev/snd/seq: dan 6354 F.... pipewire CasperMD5CheckMismatches: ./EFI/boot/bootx64.efi ./EFI/boot/grubx64.efi ./EFI/boot/mmx64.efi CasperMD5CheckResult: fail CurrentDesktop: ubuntu:GNOME Date: Thu Apr 30 10:29:41 2026 MachineType: Dell Inc. Dell Pro Max 14 Premium MA14250 ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/zsh TERM=xterm-ghostty XDG_RUNTIME_DIR=<set> ProcFB: 0 i915drmfb ProcKernelCmdLine: snapd_recovery_mode=run console=ttyS0,115200n8 console=tty1 panic=-1 quiet splash snapd.xkb="us,pc105,," RebootRequiredPkgs: Error: path contained symlinks. SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 12/11/2025 dmi.bios.release: 1.7 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.7.1 dmi.board.name: 06XRHN dmi.board.vendor: Dell Inc. dmi.board.version: A02 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.ec.firmware.release: 1.6 dmi.modalias: dmi:bvnDellInc.:bvr1.7.1:bd12/11/2025:br1.7:efr1.6:svnDellInc.:pnDellProMax14PremiumMA14250:pvr:rvnDellInc.:rn06XRHN:rvrA02:cvnDellInc.:ct10:cvr:sku0D32:pfaDellProMaxLaptops: dmi.product.family: Dell Pro Max Laptops dmi.product.name: Dell Pro Max 14 Premium MA14250 dmi.product.sku: 0D32 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/canonical-kernel-snaps/+bug/2150769/+subscriptions

[Bug 2150769] Re: pc-kernel snaps are missing some intel firmware but it also cannot be installed by users manually

For anyone who comes across this issue and wants a relatively easy workaround: 1. Create a new directory, like `/usr/local/lib/firmware` for example 2. Add this path to the firmware loader: `echo -n /usr/local/lib/firmware > /sys/module/firmware_class/parameters/path` 3. The kernel will now search `/usr/local/lib/firmware` for the relevant firmware files before searching other locations. To make it even easier, I created a script called `/usr/local/lib/firmware/local-firmware.sh` which does step 2, then I created `/etc/modprobe.d/iwlwifi.conf` and added the following line: `install iwlwifi /usr/local/lib/firmware/local-firmware.sh && /sbin/modprobe --ignore-install iwlwifi` What this does is tell modprobe that in order to install the iwlwifi module, run the `local-firmware.sh` script first, then run `/sbin/modprobe --ignore-install iwlwifi` (we need `--ignore-install` to ignore the `install` line we just added, otherwise it will run itself which runs itself, etc. forever). This way, attempting to load the iwlwifi module will automatically add `/usr/local/lib/firmware` to our firmware path first. You can do the same thing with any other kernel module (or any other command). Caveats: 1. The shell script you write runs automatically as root without confirmation whenever the system tries to load the module, so make sure it's somewhere that only root can access/edit/run it. 2. This only works if the module, script, and firmware are all accessible; if you're trying to do this with a kernel module which loads in the initrd phase it may be significantly more complex to implement as you'll need to copy the firmware and the script to the initrd for it to work. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2150769 Title: pc-kernel snaps are missing some intel firmware but it also cannot be installed by users manually Status in canonical-kernel-snaps: Confirmed Status in boot-managed-by-snapd package in Ubuntu: New Status in linux package in Ubuntu: Invalid Status in linux-firmware-intel-wireless package in Ubuntu: Invalid Bug description: I described in detail here, in case I miss anything in this description: https://discourse.ubuntu.com/t/the-pc-kernel-snap- on-26-04-prevents-users-from-installing-additional-firmware/81404 This bug report is pretty wordy so here's a top-line summary: 1. The pc-kernel snap uses an unfortunately unreliable method of including firmware, which means some firmware gets missed 2. The apt dependencies of `boot-managed-by-snapd` preclude installing `linux-firmware` but do not preclude installing any other firmware packages making it possible to break your system in a pretty dramatic way that many users might have a very difficult time figuring out or resolving. Reproduction steps: 1. Install Ubuntu using the `pc-kernel` snap rather than apt kernel packages 2. Install the `linux-firmware-intel-wireless` package Okay, now on to the verbose part of the bug report which I hope is at least partially understandable. Circumstance: 1. I'm running Ubuntu 26.04 using the pc-kernel snapo (because of hardware FDE I guess) 2. My laptop has a pretty new Arrow Lake chipset with an Intel wifi adapter 3. My wifi doesn't work What I discovered while debugging: the `iwlwifi` module won't load properly because it can't find the firmware file it wants, as it is not present in the `pc-kernel` snap, so wifi doesn't work. This took me in a few different directions and this is what I found: * Unspecified incompatibility between pc-kernel and additional firmware packages First, the pc-kernel snap creates symlinks to everything in its 'firmware' directory into the filesystem that gets mounted at /usr/lib/firmware, but it links everything at the top-level. That means firmware can be added to e.g. /usr/lib/firmware/somefile.fw, because that's a directory, but not /usr/lib/firmware/intel/somefile.fw because /usr/lib/firmware/intel is a symlink to a directory on the squashfs filesystem. This means that installing the `linux-firmware-intel-wireless` package, which has the firmware I need: 1. Breaks when trying to install because it tries to write some files to /usr/lib/firmware/intel/ 2. Refuses to uninstall until it's installed correctly, because dpkg recognizes it as being in an extremely broken state. I say 'unspecified' because `boot-managed-by-snapd` explicitly conflicts with `linux-firmware` (showing the intention to not allow both at once), but it does not conflict with any additional firmware packages. * Incomplete firmware inventory in the pc-kernel snap I dug into it a bit and found that the pc-kernel snap builds using the following steps: 1. Get the kernel and the modules together 2. Ask each module what firmware it wants (via `modinfo`) 3. Bundle those firmwares into the pc-kernel snap Unfortunately, for whatever reason, the `iwlwifi` firmware does not specify the firmware that my system seems to insist on, which is `bz-b0-fm-c0-c101.ucode`, so it does not get included into the pc- kernel snap. The `linux-firmware-intel-wireless` debian package *does* include this firmware, presumably because it just includes all available Intel wireless firmware unconditionally. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-14-generic (not installed) ProcVersionSignature: Ubuntu 7.0.0-14.14-generic 7.0.0 Uname: Linux 7.0.0-14-generic x86_64 ApportVersion: 2.34.0-0ubuntu2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC2: dan 6392 F.... wireplumber /dev/snd/controlC1: dan 6392 F.... wireplumber /dev/snd/controlC0: dan 6392 F.... wireplumber /dev/snd/seq: dan 6354 F.... pipewire CasperMD5CheckMismatches: ./EFI/boot/bootx64.efi ./EFI/boot/grubx64.efi ./EFI/boot/mmx64.efi CasperMD5CheckResult: fail CurrentDesktop: ubuntu:GNOME Date: Thu Apr 30 10:29:41 2026 MachineType: Dell Inc. Dell Pro Max 14 Premium MA14250 ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/zsh TERM=xterm-ghostty XDG_RUNTIME_DIR=<set> ProcFB: 0 i915drmfb ProcKernelCmdLine: snapd_recovery_mode=run console=ttyS0,115200n8 console=tty1 panic=-1 quiet splash snapd.xkb="us,pc105,," RebootRequiredPkgs: Error: path contained symlinks. SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 12/11/2025 dmi.bios.release: 1.7 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.7.1 dmi.board.name: 06XRHN dmi.board.vendor: Dell Inc. dmi.board.version: A02 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.ec.firmware.release: 1.6 dmi.modalias: dmi:bvnDellInc.:bvr1.7.1:bd12/11/2025:br1.7:efr1.6:svnDellInc.:pnDellProMax14PremiumMA14250:pvr:rvnDellInc.:rn06XRHN:rvrA02:cvnDellInc.:ct10:cvr:sku0D32:pfaDellProMaxLaptops: dmi.product.family: Dell Pro Max Laptops dmi.product.name: Dell Pro Max 14 Premium MA14250 dmi.product.sku: 0D32 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/canonical-kernel-snaps/+bug/2150769/+subscriptions

[Bug 2161289] Re: Kernel 7.0.0-28-generic: system hangs on shutdown/reboot on ThinkPad T14 Gen 2 AMD

Same Issue here systemd[1]: Reached target final.target - Late Shutdown Services. systemd[1]: systemd-poweroff.service: Deactivated successfully. systemd[1]: Finished systemd-poweroff.service - System Power Off. systemd[1]: Reached target poweroff.target - System Power Off. systemd[1]: Shutting down. But system hangs, tower leds stay on and fans spin, no video output, requiring to hold the power button for five seconds. System: Kernel: 6.17.0-40-generic arch: x86_64 bits: 64 Desktop: Cinnamon v: 6.6.9 Distro: Linux Mint 22.3 Zena Machine: Type: Desktop Mobo: Micro-Star model: B760 GAMING PLUS WIFI (MS-7D98) v: 3.0 serial: <superuser required> UEFI: American Megatrends LLC. v: H.A0 date: 09/30/2024 CPU: Info: 10-core (6-mt/4-st) model: 12th Gen Intel Core i5-12600K bits: 64 type: MST AMCP cache: L2: 9.5 MiB Speed (MHz): avg: 802 min/max: 800/4900:3600 cores: 1: 800 2: 800 3: 799 4: 800 5: 800 6: 800 7: 800 8: 800 9: 800 10: 800 11: 800 12: 839 13: 800 14: 800 15: 800 16: 800 Graphics: Device-1: AMD Navi 32 [Radeon RX 7700 XT / 7800 XT] driver: amdgpu v: kernel Display: x11 server: X.Org v: 21.1.11 with: Xwayland v: 23.2.6 driver: X: loaded: amdgpu dri: radeonsi gpu: amdgpu resolution: 1: 2560x1440 2: 1920x1080~144Hz API: EGL v: 1.5 drivers: kms_swrast,radeonsi,swrast platforms: gbm,x11,surfaceless,device API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 25.2.8-0ubuntu0.24.04.2 renderer: AMD Radeon RX 7700 XT (radeonsi navi32 LLVM 20.1.2 DRM 3.64 6.17.0-40-generic) API: Vulkan v: 1.3.275 drivers: N/A surfaces: xcb,xlib Audio: Device-1: Intel Raptor Lake High Definition Audio driver: snd_hda_intel Device-2: AMD Navi 31 HDMI/DP Audio driver: snd_hda_intel API: ALSA v: k6.17.0-40-generic status: kernel-api Server-1: PipeWire v: 1.0.5 status: active Network: Device-1: Intel Raptor Lake-S PCH CNVi WiFi driver: iwlwifi IF: wlo1 state: down mac: <filter> Device-2: Realtek RTL8125 2.5GbE driver: r8169 IF: enp5s0 state: up speed: 1000 Mbps duplex: full mac: <filter> Bluetooth: Device-1: Intel AX211 Bluetooth driver: btusb type: USB Report: hciconfig ID: hci0 state: up address: <filter> bt-v: 5.3 Drives: Local Storage: total: 931.51 GiB used: 30.82 GiB (3.3%) ID-1: /dev/nvme0n1 vendor: Western Digital model: WD BLACK SN850X 1000GB size: 931.51 GiB Partition: ID-1: / size: 91.64 GiB used: 30.79 GiB (33.6%) fs: ext4 dev: /dev/nvme0n1p5 ID-2: /boot/efi size: 196 MiB used: 37.8 MiB (19.3%) fs: vfat dev: /dev/nvme0n1p1 Swap: ID-1: swap-1 type: file size: 2 GiB used: 0 KiB (0.0%) file: /swapfile Sensors: System Temperatures: cpu: 48.0 C mobo: N/A gpu: amdgpu temp: 57.0 C Fan Speeds (rpm): N/A gpu: amdgpu fan: 476 Info: Memory: total: 32 GiB note: est. available: 31.12 GiB used: 4.64 GiB (14.9%) Processes: 423 Uptime: 19m Shell: Bash inxi: 3.3.34 Fixed by switching back to Kernel 6.17.0-40. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2161289 Title: Kernel 7.0.0-28-generic: system hangs on shutdown/reboot on ThinkPad T14 Gen 2 AMD Status in linux package in Ubuntu: Confirmed Bug description: ## Summary On Ubuntu 26.04 LTS, kernel 7.0.0-28-generic fails to shutdown or reboot properly on ThinkPad T14 Gen 2 (Ryzen 5 Pro). System reaches final.target, black screen, but power LED stays on indefinitely. ## Affected Hardware - ThinkPad T14 Gen 2 (Type 20UF) - AMD Ryzen 5 Pro 5650U - Integrated AMD Vega Graphics (amdgpu) ## Affected Kernel - 7.0.0-28-generic: FAILS - 7.0.0-27-generic: WORKS ## Steps to Reproduce 1. Boot kernel 7.0.0-28 2. Attempt shutdown or reboot via UI or CLI 3. System hangs with black screen, power LED remains on 4. Requires force power-off ## Root Cause systemd successfully reaches shutdown.target and final.target (journalctl confirms all services stopped cleanly). System hangs at kernel ACPI power management stage, likely amdgpu driver regression in 7.0.0-28. ## Workaround Downgrade to kernel 7.0.0-27-generic. 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: 2.34.0-0ubuntu2 Architecture: amd64 CasperMD5CheckMismatches: ./boot/grub/grub.cfg CasperMD5CheckResult: fail CurrentDesktop: ubuntu:GNOME Date: Mon Jul 20 00:18:57 2026 InstallationDate: Installed on 2026-05-08 (72 days ago) InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1) MachineType: LENOVO 20XLS0T500 ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-kitty XDG_RUNTIME_DIR=<set> ProcFB: 0 amdgpudrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-27-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro pcie_aspm=off pci=noaer acpi=debug 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: 04/16/2026 dmi.bios.release: 1.34 dmi.bios.vendor: LENOVO dmi.bios.version: R1MET64W (1.34 ) dmi.board.asset.tag: Not Available dmi.board.name: 20XLS0T500 dmi.board.vendor: LENOVO dmi.board.version: SDK0J40697 WIN dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.ec.firmware.release: 1.34 dmi.modalias: dmi:bvnLENOVO:bvrR1MET64W(1.34):bd04/16/2026:br1.34:efr1.34:svnLENOVO:pn20XLS0T500:pvrThinkPadT14Gen2a:rvnLENOVO:rn20XLS0T500:rvrSDK0J40697WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_20XL_BU_Think_FM_ThinkPadT14Gen2a:pfaThinkPadT14Gen2a: dmi.product.family: ThinkPad T14 Gen 2a dmi.product.name: 20XLS0T500 dmi.product.sku: LENOVO_MT_20XL_BU_Think_FM_ThinkPad T14 Gen 2a dmi.product.version: ThinkPad T14 Gen 2a dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161289/+subscriptions

[Bug 2161970] [NEW] [regression] Acer Aspire A14-52MT has no audio on HDMI, speakers, or 3.5 mm jack with 7.0.0-28; 6.17.0-40 works

Public bug reported: Ubuntu 24.04.4 LTS on an Acer Aspire A14-52MT (Intel Lunar Lake) loses all physical audio output when booted with the Noble HWE kernel `7.0.0-28-generic`. The audio devices are enumerated normally. PipeWire and WirePlumber are running, the correct sinks can be selected, volumes are non-zero and unmuted, the HDMI ELD is valid, and ALSA playback reaches the `RUNNING` state. Nevertheless, HDMI, the internal speakers, and headphones connected to the laptop's 3.5 mm jack remain silent. Booting the same installation with `6.17.0-40-generic` immediately restores audio without any configuration or hardware changes. ### Hardware and software - Laptop: Acer Aspire A14-52MT - BIOS: V1.02, 2025-01-06 - Audio controller: Intel Lunar Lake-M HD Audio Controller `[8086:a828]` - Graphics controller used for HDMI: Intel Lunar Lake `[8086:64a0]`, `xe` driver - Audio driver: `sof-audio-pci-intel-lnl` - Analog codec: Realtek ALC245 - Ubuntu: 24.04.4 LTS (Noble) - Bad kernel: `7.0.0-28-generic` (`7.0.0-28.28~24.04.1`) - Good kernel: `6.17.0-40-generic` (`6.17.0-40.40~24.04.1`) - SOF firmware: `2.14.1.1` - Topology: `intel/sof-ipc4-tplg/sof-hda-generic-2ch.tplg` ### Steps to reproduce 1. Boot Ubuntu with `7.0.0-28-generic`. 2. Select `sof-hda-dsp Speaker + Headphones` or the HDMI output. 3. Play normal desktop audio or run: `speaker-test -D hw:0,0 -c 2 -r 48000 -F S16_LE -t wav -l 1` For HDMI: `speaker-test -D hw:0,3 -c 2 -r 48000 -F S16_LE -t wav -l 1` 4. Observe that playback completes without an ALSA error but no sound is heard. 5. Reboot into `6.17.0-40-generic` and repeat the test. 6. Audio works normally. ### Expected result Audio is audible from the selected HDMI or analog output with `7.0.0-28-generic`, as it is with `6.17.0-40-generic`. ### Actual result All physical audio outputs are silent with `7.0.0-28-generic`. ### Diagnostic observations - `wpctl status` exposes all expected sinks on both kernels. - The HDMI monitor is detected with a valid ELD and stereo LPCM support. - `Master`, `Headphone`, `Speaker`, and the relevant IEC958 playback switches are enabled. - Direct ALSA tests and PipeWire-targeted tests are both silent on 7.0. - The same installed SOF firmware, topology, ALSA UCM configuration, monitor, cable, and user-space audio stack are used on both boots. - The kernel initialization logs do not show an obvious audio error and are nearly identical, making the good/bad kernel comparison important. - Reproducibility: 100% in the tested boots. ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: noble regression-update ** Attachment added: "audio-kernel-regression-sanitized.log" https://bugs.launchpad.net/bugs/2161970/+attachment/5987349/+files/audio-kernel-regression-sanitized.log -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2161970 Title: [regression] Acer Aspire A14-52MT has no audio on HDMI, speakers, or 3.5 mm jack with 7.0.0-28; 6.17.0-40 works Status in linux package in Ubuntu: New Bug description: Ubuntu 24.04.4 LTS on an Acer Aspire A14-52MT (Intel Lunar Lake) loses all physical audio output when booted with the Noble HWE kernel `7.0.0-28-generic`. The audio devices are enumerated normally. PipeWire and WirePlumber are running, the correct sinks can be selected, volumes are non-zero and unmuted, the HDMI ELD is valid, and ALSA playback reaches the `RUNNING` state. Nevertheless, HDMI, the internal speakers, and headphones connected to the laptop's 3.5 mm jack remain silent. Booting the same installation with `6.17.0-40-generic` immediately restores audio without any configuration or hardware changes. ### Hardware and software - Laptop: Acer Aspire A14-52MT - BIOS: V1.02, 2025-01-06 - Audio controller: Intel Lunar Lake-M HD Audio Controller `[8086:a828]` - Graphics controller used for HDMI: Intel Lunar Lake `[8086:64a0]`, `xe` driver - Audio driver: `sof-audio-pci-intel-lnl` - Analog codec: Realtek ALC245 - Ubuntu: 24.04.4 LTS (Noble) - Bad kernel: `7.0.0-28-generic` (`7.0.0-28.28~24.04.1`) - Good kernel: `6.17.0-40-generic` (`6.17.0-40.40~24.04.1`) - SOF firmware: `2.14.1.1` - Topology: `intel/sof-ipc4-tplg/sof-hda-generic-2ch.tplg` ### Steps to reproduce 1. Boot Ubuntu with `7.0.0-28-generic`. 2. Select `sof-hda-dsp Speaker + Headphones` or the HDMI output. 3. Play normal desktop audio or run: `speaker-test -D hw:0,0 -c 2 -r 48000 -F S16_LE -t wav -l 1` For HDMI: `speaker-test -D hw:0,3 -c 2 -r 48000 -F S16_LE -t wav -l 1` 4. Observe that playback completes without an ALSA error but no sound is heard. 5. Reboot into `6.17.0-40-generic` and repeat the test. 6. Audio works normally. ### Expected result Audio is audible from the selected HDMI or analog output with `7.0.0-28-generic`, as it is with `6.17.0-40-generic`. ### Actual result All physical audio outputs are silent with `7.0.0-28-generic`. ### Diagnostic observations - `wpctl status` exposes all expected sinks on both kernels. - The HDMI monitor is detected with a valid ELD and stereo LPCM support. - `Master`, `Headphone`, `Speaker`, and the relevant IEC958 playback switches are enabled. - Direct ALSA tests and PipeWire-targeted tests are both silent on 7.0. - The same installed SOF firmware, topology, ALSA UCM configuration, monitor, cable, and user-space audio stack are used on both boots. - The kernel initialization logs do not show an obvious audio error and are nearly identical, making the good/bad kernel comparison important. - Reproducibility: 100% in the tested boots. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161970/+subscriptions

[Bug 2161943] Re: The built-in MIPI camera (Intel IPU6, OV08x40 sensor) does not work.

*** This bug is a duplicate of bug 2161944 *** https://bugs.launchpad.net/bugs/2161944 ** This bug has been marked a duplicate of bug 2161944 The built-in MIPI camera (Intel IPU6, OV08x40 sensor) does not work. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2161943 Title: The built-in MIPI camera (Intel IPU6, OV08x40 sensor) does not work. Status in linux package in Ubuntu: New Bug description: The sensor never powers up because its power-management chip (INT3472) cannot obtain its GPIOs from the USB-attached USBIO GPIO bridge (ACPI `INTC10B2`) at boot. As a result the sensor's I2C client is never created, no `/dev/v4l-subdev*` is registered, the sensor never appears in the IPU6 media graph, and libcamera reports "No sensor found". Userspace apps therefore see no built-in camera. An external Logitech Brio USB webcam works normally. ## Affected system - OS: Ubuntu 26.04 LTS (Resolute Raccoon) - Kernel: 7.0.0-28-generic (also installed: 6.14.0-37-generic) - Hostname: vidyut - SoC: Intel Meteor Lake; IPU: `00:05.0 Multimedia controller: Intel Corporation Meteor Lake IPU (rev 05)` - Sensor: OVTI08F4 / ov08x40 - Camera power chips: INT3472:0b, INT3472:0c (driver: int3472-discrete) - GPIO/I2C bridge: "SLS Lattice AI USB 2.0" (USB ID 2ac1:20c9) exposing usbio-gpio (INTC10B2) + usbio-i2c ## Root cause (evidence) ### 1. INT3472 defers forever at boot waiting for the USB GPIO bridge The USBIO GPIO controller (`INTC10B2`) is a USB device and enumerates late. INT3472 probes first and defers ~40 times: ``` [12.381] int3472-discrete INT3472:0b: cannot find GPIO chip INTC10B2:00, deferring [12.400] int3472-discrete INT3472:0c: cannot find GPIO chip INTC10B2:00, deferring ... (repeats until ~12.998s) ... ``` ### 2. USBIO GPIO firmware reports a broken pin bitmap ``` [13.002] gpio_usbio.usbio-gpio usbio.usbio-gpio.0: [Firmware Bug]: GPIO 8 is not in FW pins bitmap ``` ### 3. After the GPIO chip appears, INT3472 has "no dependents" Reloading the int3472 modules once `INTC10B2` is present makes the deferral stop, but: ``` [1393.288] int3472-discrete INT3472:0b: INT3472 seems to have no dependents. [1393.288] int3472-discrete INT3472:0c: INT3472 seems to have no dependents. ``` The sensor was never registered against its power provider, so it is never powered. ### 4. Downstream symptoms - `ov08x40` module is loaded but bound to no device (no symlink in `/sys/bus/i2c/drivers/ov08x40/`, module refcnt 0). - No `ov08x40` / `OVTI08F4` I2C client exists on any adapter (including usbio-i2c `i2c-17`/`i2c-18`). - No `/dev/v4l-subdev*` nodes. - IPU6 media graph (`/dev/media1`) has CSI2 receivers but **no sensor entity**. - libcamera: `SimplePipeline simple.cpp:1899 INFO No sensor found for /dev/media1`. - Note: `INTC10B2:00` gpiochip *is* present at runtime (`/sys/class/gpio/gpiochip963` label `INTC10B2:00`), i.e. the bridge does eventually enumerate — the failure is the boot-time probe ordering plus the missing sensor<->INT3472 linkage. ## Impact Built-in camera completely non-functional in all applications (browser, video conferencing, Cheese/Snapshot). External USB webcams unaffected. ## Reproducibility Occurs on every boot; long-standing. Reloading `ov08x40`/IPU6 modules does not help. Reloading the INT3472 chain after the USB GPIO bridge is up removes the deferral but yields "INT3472 seems to have no dependents" — the sensor is still not created. ## Suspected fix areas - Probe-ordering / deferred-probe handling so INT3472 (and the sensor I2C client on the USBIO I2C bus) retry successfully once the USB `usbio` bridge (INTC10B2 / usbio-i2c) enumerates. - USBIO GPIO firmware/driver pin-bitmap quirk ("GPIO 8 is not in FW pins bitmap") so the camera reset/powerdown GPIO can be acquired. - ipu_bridge / int3472-discrete linkage so INT3472 does not end up with "no dependents". ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-28-generic 7.0.0-28.28 ProcVersionSignature: Ubuntu 7.0.0-28.28-generic 7.0.12 Uname: Linux 7.0.0-28-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Tue Jul 28 11:36:07 2026 InstallationDate: Installed on 2025-11-20 (250 days ago) InstallationMedia: Ubuntu 25.04 "Plucky Puffin" - Release amd64 (20250415.3) MachineType: LENOVO 21NYCTO1WW ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/usr/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-28-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 06/23/2025 dmi.bios.release: 1.11 dmi.bios.vendor: LENOVO dmi.bios.version: N4MET24W (1.11 ) dmi.board.asset.tag: Not Available dmi.board.name: 21NYCTO1WW dmi.board.vendor: LENOVO dmi.board.version: Not Defined dmi.chassis.asset.tag: No Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.ec.firmware.release: 1.4 dmi.modalias: dmi:bvnLENOVO:bvrN4MET24W(1.11):bd06/23/2025:br1.11:efr1.4:svnLENOVO:pn21NYCTO1WW:pvrThinkPadX1CarbonGen13:rvnLENOVO:rn21NYCTO1WW:rvrNotDefined:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_21NY_BU_Think_FM_ThinkPadX1CarbonGen13:pfaThinkPadX1CarbonGen13: dmi.product.family: ThinkPad X1 Carbon Gen 13 dmi.product.name: 21NYCTO1WW dmi.product.sku: LENOVO_MT_21NY_BU_Think_FM_ThinkPad X1 Carbon Gen 13 dmi.product.version: ThinkPad X1 Carbon Gen 13 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161943/+subscriptions

[Bug 2150545] Re: Possibly snd_hda_intel / Realtek ALC1150 jack detection issue: analog jacks report unavailable although ALSA surround51 playback works

Final update / correction: The previously mentioned user systemd workaround is no longer in use. After further testing, I removed all local audio workarounds: - removed PULSE_SINK environment override - removed audio-route-watch.service - removed route-audio-to-current-device script - disabled and removed fix-audio-profile.service After reboot, with no local audio workarounds active, PipeWire selects the correct sink automatically: Default Sink: alsa_output.pci-0000_00_1b.0.analog-surround-51 Playback works through the 5.1 speakers, and USB headset hotplug also works correctly: - plugging in USB headset switches output/input to the headset - unplugging it switches output back to analog-surround-51 - playback works after both transitions Conclusion: this bug report was caused by incorrect physical 5.1 cabling on my system. The front L/R speakers had been connected to the gray side-speaker jack instead of the green/lime front-speaker jack. After correcting the cabling and resetting stale WirePlumber user state, I can no longer reproduce the reported issue. I believe this report can be closed as Invalid / not a software bug. ** Changed in: linux (Ubuntu) Status: Incomplete => Invalid ** Changed in: pipewire (Ubuntu) Status: Incomplete => Invalid -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2150545 Title: Possibly snd_hda_intel / Realtek ALC1150 jack detection issue: analog jacks report unavailable although ALSA surround51 playback works Status in linux package in Ubuntu: Invalid Status in pipewire package in Ubuntu: Invalid Status in wireplumber package in Ubuntu: Invalid Bug description: Hardware: Realtek ALC1150 on Intel HDA PCH Problem: After login/reboot, Ubuntu selects: alsa_output.pci-0000_00_1b.0.iec958-stereo But actual speakers are connected to analog 5.1. PipeWire/WirePlumber marks analog profiles as: available: no However ALSA direct playback works: speaker-test -D surround51:0 -c 6 -t wav -l 1 speaker-test -D hw:0,0 -c 6 -r 48000 -F S16_LE -t wav -l 1 Workaround: pactl set-card-profile alsa_card.pci-0000_00_1b.0 output:analog-surround-51+input:analog-stereo pactl set-default-sink alsa_output.pci-0000_00_1b.0.analog-surround-51 PULSE_SINK=alsa_output.pci-0000_00_1b.0.analog-surround-51 ProblemType: Bug DistroRelease: Ubuntu 24.04 Package: wireplumber 0.4.17-1ubuntu4.1 ProcVersionSignature: Ubuntu 6.8.0-110.110-generic 6.8.12 Uname: Linux 6.8.0-110-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.28.1-0ubuntu3.8 Architecture: amd64 CasperMD5CheckResult: unknown CurrentDesktop: ubuntu:GNOME Date: Tue Apr 28 17:58:55 2026 InstallationDate: Installed on 2013-12-12 (4520 days ago) InstallationMedia: Ubuntu 12.04.3 LTS "Precise Pangolin" - Release amd64 (20130820.1) SourcePackage: wireplumber UpgradeStatus: No upgrade log present (probably fresh install) --- ProblemType: Bug ApportVersion: 2.28.1-0ubuntu3.8 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: andrei 2673 F.... wireplumber /dev/snd/controlC1: andrei 2673 F.... wireplumber /dev/snd/controlC2: andrei 2673 F.... wireplumber /dev/snd/seq: andrei 2670 F.... pipewire CasperMD5CheckResult: unknown CurrentDesktop: ubuntu:GNOME DistroRelease: Ubuntu 24.04 HibernationDevice: RESUME=UUID=32a545a6-2316-4106-b12c-77b5230755a7 InstallationDate: Installed on 2013-12-12 (4521 days ago) InstallationMedia: Ubuntu 12.04.3 LTS "Precise Pangolin" - Release amd64 (20130820.1) IwConfig: lo no wireless extensions. eth0 no wireless extensions. eth1 no wireless extensions. MachineType: ASUS All Series NonfreeKernelModules: nvidia_modeset nvidia Package: pipewire 1.0.5-1ubuntu3.2 PackageArchitecture: amd64 ProcFB: 0 simpledrmdrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.8.0-110-generic root=UUID=55f804c3-1293-4448-877f-9fd9a1418702 ro ProcVersionSignature: Ubuntu 6.8.0-110.110-generic 6.8.12 PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. RelatedPackageVersions: linux-restricted-modules-6.8.0-110-generic N/A linux-backports-modules-6.8.0-110-generic N/A linux-firmware 20240318.git3b128b60-0ubuntu2.27 RfKill: 0: hci0: Bluetooth Soft blocked: yes Hard blocked: no Tags: noble Uname: Linux 6.8.0-110-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip disk lpadmin netdev nordvpn plugdev sambashare sudo vboxusers wireshark _MarkForUpload: True dmi.bios.date: 06/26/2013 dmi.bios.release: 4.6 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1205 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: Z87-DELUXE dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Asset-1234567890 dmi.chassis.type: 3 dmi.chassis.vendor: Chassis Manufacture dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1205:bd06/26/2013:br4.6:svnASUS:pnAllSeries:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnZ87-DELUXE:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:skuAll: dmi.product.family: ASUS MB dmi.product.name: All Series dmi.product.sku: All dmi.product.version: System Version dmi.sys.vendor: ASUS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2150545/+subscriptions

[Bug 2161961] [NEW] Black screen after suspend/resume on HP ZBook 15 G4 with kernel 7.0.0-28

Public bug reported: Problem Description: After upgrading to kernel 7.0.0-28-generic, my HP ZBook 15 G4 laptop displays a completely black screen upon waking from suspend (closing and opening the lid). The system appears to be running (fans, LEDs active) but the display remains off. The only way to recover is to force a hard shutdown by holding the power button. This issue did not exist with kernel 6.17.0-41-generic, where suspend/resume worked perfectly. System Information: - Laptop Model: HP ZBook 15 G4 - Graphics Card: NVIDIA Quadro M1200 or M2200 (Hybrid/Discrete) - OS: Ubuntu (version 24.10 or 25.04 - please confirm based on kernel) - Current Kernel: 7.0.0-28-generic - Previous Working Kernel: 6.17.0-41-generic Steps to Reproduce: 1. Boot the system with kernel 7.0.0-28-generic. 2. Close the lid or manually suspend the system (sudo systemctl suspend). 3. Wait a few seconds. 4. Open the lid or press any key to wake the system. 5. The screen remains black and unresponsive. No backlight, no display output. Expected Behavior: The display should turn on and show the login screen or desktop, as it does with kernel 6.17.0-41. Additional Context: I have already attempted the following workarounds without success: - Adding kernel parameters to GRUB: nvidia.NVreg_PreserveVideoMemoryAllocations=1 acpi_sleep=nonvs intel_idle.max_cstate=2 - Disabling Secure Boot and setting Graphics Mode to "Discrete" in BIOS - Reinstalling NVIDIA drivers This appears to be a regression introduced in kernel 7.0.0-28, as it works flawlessly with kernel 6.17.0-41. Please investigate the changes in DRM/NVIDIA/ACPI handling that may have caused this issue for HP ZBook G4 series laptops. I have attached the requested logs: - version.log - lspci-vnv.log Thank you for your time and efforts in resolving this issue. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-28-generic 7.0.0-28.28 ProcVersionSignature: Ubuntu 7.0.0-28.28-generic 7.0.12 Uname: Linux 7.0.0-28-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: NimaHatami 3758 F.... wireplumber /dev/snd/controlC0: NimaHatami 3758 F.... wireplumber /dev/snd/seq: NimaHatami 3742 F.... pipewire CasperMD5CheckResult: unknown CurrentDesktop: ubuntu:GNOME Date: Tue Jul 28 14:06:27 2026 MachineType: HP HP ZBook 15 G4 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=/vmlinuz-7.0.0-28-generic root=UUID=4fccc91e-5b81-4057-be81-4e0854b8b673 ro quiet splash nvidia.NVreg_PreserveVideoMemoryAllocations=1 acpi_sleep=nonvs intel_idle.max_cstate=2 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) WifiSyslog: dmi.bios.date: 12/08/2023 dmi.bios.release: 1.49 dmi.bios.vendor: HP dmi.bios.version: P70 Ver. 01.49 dmi.board.name: 8275 dmi.board.vendor: HP dmi.board.version: KBC Version 46.80 dmi.chassis.type: 10 dmi.chassis.vendor: HP dmi.ec.firmware.release: 70.128 dmi.modalias: dmi:bvnHP:bvrP70Ver.01.49:bd12/08/2023:br1.49:efr70.128:svnHP:pnHPZBook15G4:pvr:rvnHP:rn8275:rvrKBCVersion46.80:cvnHP:ct10:cvr:skuY4E78AV:pfa103C_5336AN: dmi.product.family: 103C_5336AN dmi.product.name: HP ZBook 15 G4 dmi.product.sku: Y4E78AV dmi.sys.vendor: HP ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug resolute wayland-session -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2161961 Title: Black screen after suspend/resume on HP ZBook 15 G4 with kernel 7.0.0-28 Status in linux package in Ubuntu: New Bug description: Problem Description: After upgrading to kernel 7.0.0-28-generic, my HP ZBook 15 G4 laptop displays a completely black screen upon waking from suspend (closing and opening the lid). The system appears to be running (fans, LEDs active) but the display remains off. The only way to recover is to force a hard shutdown by holding the power button. This issue did not exist with kernel 6.17.0-41-generic, where suspend/resume worked perfectly. System Information: - Laptop Model: HP ZBook 15 G4 - Graphics Card: NVIDIA Quadro M1200 or M2200 (Hybrid/Discrete) - OS: Ubuntu (version 24.10 or 25.04 - please confirm based on kernel) - Current Kernel: 7.0.0-28-generic - Previous Working Kernel: 6.17.0-41-generic Steps to Reproduce: 1. Boot the system with kernel 7.0.0-28-generic. 2. Close the lid or manually suspend the system (sudo systemctl suspend). 3. Wait a few seconds. 4. Open the lid or press any key to wake the system. 5. The screen remains black and unresponsive. No backlight, no display output. Expected Behavior: The display should turn on and show the login screen or desktop, as it does with kernel 6.17.0-41. Additional Context: I have already attempted the following workarounds without success: - Adding kernel parameters to GRUB: nvidia.NVreg_PreserveVideoMemoryAllocations=1 acpi_sleep=nonvs intel_idle.max_cstate=2 - Disabling Secure Boot and setting Graphics Mode to "Discrete" in BIOS - Reinstalling NVIDIA drivers This appears to be a regression introduced in kernel 7.0.0-28, as it works flawlessly with kernel 6.17.0-41. Please investigate the changes in DRM/NVIDIA/ACPI handling that may have caused this issue for HP ZBook G4 series laptops. I have attached the requested logs: - version.log - lspci-vnv.log Thank you for your time and efforts in resolving this issue. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-28-generic 7.0.0-28.28 ProcVersionSignature: Ubuntu 7.0.0-28.28-generic 7.0.12 Uname: Linux 7.0.0-28-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: NimaHatami 3758 F.... wireplumber /dev/snd/controlC0: NimaHatami 3758 F.... wireplumber /dev/snd/seq: NimaHatami 3742 F.... pipewire CasperMD5CheckResult: unknown CurrentDesktop: ubuntu:GNOME Date: Tue Jul 28 14:06:27 2026 MachineType: HP HP ZBook 15 G4 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=/vmlinuz-7.0.0-28-generic root=UUID=4fccc91e-5b81-4057-be81-4e0854b8b673 ro quiet splash nvidia.NVreg_PreserveVideoMemoryAllocations=1 acpi_sleep=nonvs intel_idle.max_cstate=2 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) WifiSyslog: dmi.bios.date: 12/08/2023 dmi.bios.release: 1.49 dmi.bios.vendor: HP dmi.bios.version: P70 Ver. 01.49 dmi.board.name: 8275 dmi.board.vendor: HP dmi.board.version: KBC Version 46.80 dmi.chassis.type: 10 dmi.chassis.vendor: HP dmi.ec.firmware.release: 70.128 dmi.modalias: dmi:bvnHP:bvrP70Ver.01.49:bd12/08/2023:br1.49:efr70.128:svnHP:pnHPZBook15G4:pvr:rvnHP:rn8275:rvrKBCVersion46.80:cvnHP:ct10:cvr:skuY4E78AV:pfa103C_5336AN: dmi.product.family: 103C_5336AN dmi.product.name: HP ZBook 15 G4 dmi.product.sku: Y4E78AV dmi.sys.vendor: HP To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161961/+subscriptions

[Bug 2161575] Re: [regression] 7.0.0-28: eDP backlight stays off after resume on ThinkPad T480 (i915 selects DPCD/AUX backlight instead of native PWM)

Thanks Alice, and thanks to Krystian for the analysis on #2161309. I agree this strongly looks like a duplicate of #2161309. The symptom, the hardware class (ThinkPad T480, Intel UHD Graphics 620), and the regression range (7.0.0-27 good, 7.0.0-28 bad) all match, and was reported just a couple days earlier. On the request to test mainline 7.1.4: I am unable to boot the Ubuntu mainline builds on this machine in a straightforward way. As it's a daily-driver work laptop, Secure Boot is enabled and the UEFI supervisor password is set and not available to me, so I cannot enter firmware setup to disable Secure Boot. The mainline builds ship as linux-image- unsigned, which I think the firmware will reject? Enrolling a Machine Owner Key to sign the mainline vmlinuz seems possible in principle (MOK enrollment does not need the firmware password), but I would rather not add a self-signed key to this machine's key store just for a one-off test. Given that #2161309 already confirms 7.1.4 fixes this on the same model (T480 / UHD 620), and that commit f30fddb4402313aa5301a74d721638d343395269 has been identified as the fix, I am comfortable relying on that confirmation rather than reproducing it on this unit. I can verify the fix on this machine once the SRU lands, by removing the i915.enable_dpcd_backlight=0 workaround and running suspend/resume on the updated kernel. If per-unit confirmation on this exact panel (LG LP140WF6-SPB7) is needed before the SRU, do let me know and I will MOK-sign a mainline 7.1.4 build and report back. In the meantime this machine is running 7.0.0-28 with i915.enable_dpcd_backlight=0 set in the GRUB options, and resume works reliably. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2161575 Title: [regression] 7.0.0-28: eDP backlight stays off after resume on ThinkPad T480 (i915 selects DPCD/AUX backlight instead of native PWM) Status in linux package in Ubuntu: Incomplete Bug description: **Package:** linux-image-generic-hwe-26.04 7.0.0-28.28 **Regression:** yes, 7.0.0-27.27 -> 7.0.0-28.28 **Tags:** `regression-update kernel-bug i915 suspend-resume backlight resolute` ## Summary After upgrading to kernel 7.0.0-28, the internal display backlight does not come on when resuming from suspend. The machine is running after resume (it accepted a blind `sudo reboot` typed at the dark screen), but the backlight stays off. Increasing brightness with the brightness keys does not bring it on. The panel is still driving an image: screen contents are legible under a bright external light. The failure is therefore confined to the backlight, not a modeset or output failure. Booting 7.0.0-27 avoids the problem. Booting 7.0.0-28 with `i915.enable_dpcd_backlight=0` also avoids it. ## Hardware - **Machine:** Lenovo ThinkPad T480, machine type 20L6S0MD00 - **BIOS:** N24ET81W (1.56), 2025-09-06 - **GPU:** Intel Kaby Lake-R GT2 [UHD Graphics 620] `[8086:5917]` rev 07, subsystem `[17aa:225d]` (lspci reports "Lenovo ThinkPad T480 (20L5)") - **Panel:** LG Display LP140WF6-SPB7 on eDP-1 (model string read from EDID) - **OS:** Ubuntu 26.04 LTS (resolute) ## Steps to reproduce 1. Boot 7.0.0-28-generic with stock kernel parameters (`quiet splash`). 2. Suspend. The journal records `PM: suspend entry (deep)`. 3. Resume. **Expected:** display lights up. **Actual:** panel stays dark. Brightness keys do not recover it. ## Observed: max_brightness differs between the two kernels Measured on this machine: | Configuration | `max_brightness` | Resume | |-------------------------------------------|------------------|--------| | 7.0.0-27, stock cmdline | **1515** | works | | 7.0.0-28, stock cmdline | **1023** | backlight off | | 7.0.0-28 + `i915.enable_dpcd_backlight=0` | **1515** | works | `enable_dpcd_backlight` reads `-1` (the default) on 7.0.0-28 when the failure occurs. *Interpretation, not measured:* 1023 is 10-bit full scale and 1515 is not a power-of-two boundary, which suggests the two kernels are driving the backlight through different control paths, and that the parameter selects between them. I have not confirmed from the driver which path is active in either case. That inference rests only on the `max_brightness` values and on the parameter changing the outcome. ## The failure is silent No errors or warnings related to the failure appear in the journal for the affected boots. `PM: suspend exit` completes, and i915 and mei_hdcp rebind. Backlight sysfs during the failure, with the panel dark: ``` /sys/class/backlight/intel_backlight/brightness 1023 /sys/class/backlight/intel_backlight/actual_brightness 1023 /sys/class/backlight/intel_backlight/max_brightness 1023 /sys/class/backlight/intel_backlight/bl_power 0 ``` `/var/lib/systemd/backlight/pci-0000:00:02.0:backlight:intel_backlight` contained `1023`, so the saved brightness value was not lost or zeroed. ## Regression range `linux-image-generic-hwe-26.04` was upgraded 7.0.0-27.27 -> 7.0.0-28.28 on **2026-07-19 18:38 (UTC+1)**, unattended via packagekit (`Commandline: packagekit role='update-packages'` in `/var/log/apt/history.log`). 7.0.0-28 first booted 2026-07-22 15:14. The three-day gap is why the update was not initially suspected. From `journalctl --list-boots` and suspend entries per boot: | Kernel | Boots | Suspends | Outcome | |----------|-------|----------|------------------------------------------| | 7.0.0-27 | 2 | 63 | boots lasted days, spanning many resumes | | 7.0.0-28 | 3 | 4 | restart 39s to 2min after first resume | The short sessions on 7.0.0-28 end because the machine was rebooted blind at a dark screen. ## Workaround Add to `GRUB_CMDLINE_LINUX_DEFAULT` in `/etc/default/grub`, then `update-grub`: ``` i915.enable_dpcd_backlight=0 ``` `max_brightness` returns to 1515 and resume works. Confirmed working after this change. I have not yet run an extended soak of many suspend cycles. ## Checked and excluded - **Not `systemd-backlight` save/restore:** the saved value was intact and sysfs read back at maximum while the panel was dark. - **Not local misconfiguration:** no i915 module parameters set, no backlight-related files in `/etc/modprobe.d`, and the cmdline was stock `quiet splash` before the workaround was added. - **A userspace resume hook did not help:** an `/etc/systemd/system-sleep/` hook that cycled `bl_power` 4 to 0 and rewrote `brightness` on resume did not light the panel. Caveat: I did not independently confirm the hook executed on resume, so this is weaker evidence than the rest of this report. ## Not verified Listing these so they are not read into the report: - Which backlight control path the driver actually selects in either kernel. - The specific upstream commit responsible. I did not bisect, and the shipped `linux-image-7.0.0-28-generic` changelog contains only packaging entries, so I could not identify a candidate change from the package itself. ## Possibly related prior art There is a history of this general symptom with DPCD/AUX backlight on i915. A commit adding a heuristic to choose automatically between AUX and PWM brightness control was reverted upstream after reportedly causing "enabling DPCD backlight leads to a black screen after suspend/resume": https://www.mail-archive.com/intel- gfx@lists.freedesktop.org/msg126115.html That report concerns different and much older hardware (a ThinkPad X1 Carbon 4th Gen and BXT-P), and predates this kernel by many releases. I offer it only as a pointer to a known failure mode in this area, not as a claim about the cause here. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-28-generic 7.0.0-28.28 ProcVersionSignature: Ubuntu 7.0.0-28.28-generic 7.0.12 Uname: Linux 7.0.0-28-generic x86_64 ApportVersion: 2.34.0-0ubuntu2 Architecture: amd64 AudioDevicesInUse:  USER PID ACCESS COMMAND  /dev/snd/controlC0: sam 3370 F.... pipewire                       sam 3389 F.... wireplumber  /dev/snd/pcmC0D0p: sam 3370 F...m pipewire  /dev/snd/seq: sam 3370 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: KDE Date: Wed Jul 22 22:51:57 2026 InstallationDate: Installed on 2026-02-13 (159 days ago) InstallationMedia: Ubuntu 24.04.1 LTS "Noble Numbat" - Release amd64 (20240827.1) MachineType: LENOVO 20L6S0MD00 ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-28-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M i915.enable_dpcd_backlight=0 PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. SourcePackage: linux UpgradeStatus: Upgraded to resolute on 2026-07-09 (13 days ago) dmi.bios.date: 09/06/2025 dmi.bios.release: 1.56 dmi.bios.vendor: LENOVO dmi.bios.version: N24ET81W (1.56 ) dmi.board.asset.tag: Not Available dmi.board.name: 20L6S0MD00 dmi.board.vendor: LENOVO dmi.board.version: SDK0J40700 WIN dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.ec.firmware.release: 1.22 dmi.modalias: dmi:bvnLENOVO:bvrN24ET81W(1.56):bd09/06/2025:br1.56:efr1.22:svnLENOVO:pn20L6S0MD00:pvrThinkPadT480:rvnLENOVO:rn20L6S0MD00:rvrSDK0J40700WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_20L6_BU_Think_FM_ThinkPadT480:pfaThinkPadT480: dmi.product.family: ThinkPad T480 dmi.product.name: 20L6S0MD00 dmi.product.sku: LENOVO_MT_20L6_BU_Think_FM_ThinkPad T480 dmi.product.version: ThinkPad T480 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161575/+subscriptions

[Bug 2154162] Re: Ubuntu 24.04.3 HWE kernel fails to install and displays stdin: Invalid argument

*** This bug is a duplicate of bug 2126559 *** https://bugs.launchpad.net/bugs/2126559 it will be very close to the end of august I think. But I've asked the team responsible for the releases to see if they can give me a better estimate than that. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2154162 Title: Ubuntu 24.04.3 HWE kernel fails to install and displays stdin: Invalid argument Status in linux package in Ubuntu: Deferred Bug description: Ubuntu 24.04.3 HWE kernel fails to install and displays stdin: Invalid argument The issue also happens with 24.04.4 HWE kernel installation. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2154162/+subscriptions

[Bug 2161948] [NEW] Panel brightness capped well below actual maximum on Dell Latitude 7390 2-in-1 (AU Optronics panel) with kernel 7.0.0-28-generic; works correctly on 6.17.0-35-generic

Public bug reported: Description: After the HWE kernel update to 7.0.0-28-generic on Ubuntu 24.04 (Zorin OS), the internal display's actual physical brightness is capped at a dim level regardless of the backlight control value reported/set via sysfs. Hardware: Dell Latitude 7390 2-in-1 Panel: AU Optronics (vendor 0x462d) GPU: Intel integrated (i915) Symptoms: Screen appears dim starting from the OS boot stage (post-BIOS/Dell logo), before any settings are applied /sys/class/backlight/intel_backlight/brightness and max_brightness both report 1023 (i.e., at 100%) Writing lower values to intel_backlight/brightness correctly dims the screen further, confirming the control path works Writing back to 1023 does not restore full brightness — the panel's actual maximum output appears capped below its true capability Confirmed NOT caused by: PSR (tested with i915.enable_psr=0, and confirmed disabled via /sys/kernel/debug/dri/.../i915_edp_psr_status), DPCD backlight mode, GNOME Night Light, GNOME idle-dim, ICC/color profile (removed ~/.local/share/icc/edid-*.icc), or user-profile settings (reproduced under a freshly created user account) Steps to reproduce: Boot Dell Latitude 7390 2-in-1 with kernel 7.0.0-28-generic Observe screen brightness is visibly dim from boot onward Confirm intel_backlight reports 100% (brightness == max_brightness) Reboot into 6.17.0-35-generic instead — brightness is correct/normal Expected behavior: Panel should reach full physical brightness when intel_backlight/brightness is at max_brightness, matching behavior on 6.17.0-35-generic. Workaround: Pinning/booting 6.17.0-35-generic instead of 7.0.0-28-generic resolves the issue completely. ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: compatibility dell display kernel -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2161948 Title: Panel brightness capped well below actual maximum on Dell Latitude 7390 2-in-1 (AU Optronics panel) with kernel 7.0.0-28-generic; works correctly on 6.17.0-35-generic Status in linux package in Ubuntu: New Bug description: Description: After the HWE kernel update to 7.0.0-28-generic on Ubuntu 24.04 (Zorin OS), the internal display's actual physical brightness is capped at a dim level regardless of the backlight control value reported/set via sysfs. Hardware: Dell Latitude 7390 2-in-1 Panel: AU Optronics (vendor 0x462d) GPU: Intel integrated (i915) Symptoms: Screen appears dim starting from the OS boot stage (post-BIOS/Dell logo), before any settings are applied /sys/class/backlight/intel_backlight/brightness and max_brightness both report 1023 (i.e., at 100%) Writing lower values to intel_backlight/brightness correctly dims the screen further, confirming the control path works Writing back to 1023 does not restore full brightness — the panel's actual maximum output appears capped below its true capability Confirmed NOT caused by: PSR (tested with i915.enable_psr=0, and confirmed disabled via /sys/kernel/debug/dri/.../i915_edp_psr_status), DPCD backlight mode, GNOME Night Light, GNOME idle-dim, ICC/color profile (removed ~/.local/share/icc/edid-*.icc), or user-profile settings (reproduced under a freshly created user account) Steps to reproduce: Boot Dell Latitude 7390 2-in-1 with kernel 7.0.0-28-generic Observe screen brightness is visibly dim from boot onward Confirm intel_backlight reports 100% (brightness == max_brightness) Reboot into 6.17.0-35-generic instead — brightness is correct/normal Expected behavior: Panel should reach full physical brightness when intel_backlight/brightness is at max_brightness, matching behavior on 6.17.0-35-generic. Workaround: Pinning/booting 6.17.0-35-generic instead of 7.0.0-28-generic resolves the issue completely. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161948/+subscriptions

[Bug 2161739] Re: Backlight brightness no longer works on Fujitsu LIFEBOOK P727 with Intel HD 620 after upgrading to Linux 7.0.0-28

*** 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/2161739 Title: Backlight brightness no longer works on Fujitsu LIFEBOOK P727 with Intel HD 620 after upgrading to Linux 7.0.0-28 Status in linux package in Ubuntu: New Bug description: After upgrading from Linux 7.0.0-27 to 7.0.0-28, the LCD backlight can no longer be adjusted. Laptop: Fujitsu LIFEBOOK P727 GPU: Intel HD Graphics 620 (Kaby Lake-U) Kubuntu 26.04 LTS /sys/class/backlight/intel_backlight/brightness and actual_brightness both change correctly. The physical display brightness never changes. KDE brightness slider and keyboard brightness keys also stop working. Booting back into Linux 7.0.0-27 immediately restores correct brightness control. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-28-generic 7.0.0-28.28 ProcVersionSignature: Ubuntu 7.0.0-28.28-generic 7.0.12 Uname: Linux 7.0.0-28-generic x86_64 ApportVersion: 2.34.0-0ubuntu2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: irfan 1619 F.... wireplumber /dev/snd/seq: irfan 1612 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: KDE Date: Fri Jul 24 19:38:24 2026 InstallationDate: Installed on 2025-11-19 (247 days ago) InstallationMedia: Kubuntu 22.04.5 LTS "Jammy Jellyfish" - Release amd64 (20240911) MachineType: FUJITSU LIFEBOOK P727 ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-28-generic root=UUID=5fd1e762-85e1-40ff-98a2-4cd01ee9a8ab ro quiet splash PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. SourcePackage: linux UpgradeStatus: Upgraded to resolute on 2026-06-06 (48 days ago) dmi.bios.date: 02/10/2025 dmi.bios.release: 1.29 dmi.bios.vendor: FUJITSU // Insyde Software Corp. dmi.bios.version: Version 1.29 dmi.board.name: FJNB2A9 dmi.board.vendor: FUJITSU dmi.board.version: G3 dmi.chassis.asset.tag: 3000000989 dmi.chassis.type: 31 dmi.chassis.vendor: FUJITSU dmi.chassis.version: LIFEBOOK P727 dmi.modalias: dmi:bvnFUJITSU//InsydeSoftwareCorp.:bvrVersion1.29:bd02/10/2025:br1.29:svnFUJITSU:pnLIFEBOOKP727:pvr10601736746:rvnFUJITSU:rnFJNB2A9:rvrG3:cvnFUJITSU:ct31:cvrLIFEBOOKP727:skuSK01:pfaLIFEBOOK-FTS: dmi.product.family: LIFEBOOK-FTS dmi.product.name: LIFEBOOK P727 dmi.product.sku: SK01 dmi.product.version: 10601736746 dmi.sys.vendor: FUJITSU To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161739/+subscriptions

[Bug 2160457] Re: Kernel panic in srso_safe_ret / kick_ilb during sched_tick on AMD Ryzen 7 4800U (Zen2)

OK, this is very likely an upstream issue not a Ubuntu kernel issue. We need to get a reproduce on a mainline kernel. Grab all the amd64 binaries from here: https://kernel.ubuntu.com/mainline/v7.2-rc5/ Run with retbleed re-enabled and when you hit the issue please provide the full splat so we can look at register dumps and see what instruction it's getting stuck on. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2160457 Title: Kernel panic in srso_safe_ret / kick_ilb during sched_tick on AMD Ryzen 7 4800U (Zen2) Status in linux package in Ubuntu: New Bug description: DESCRIPTION: == Summary == Repeated kernel panics on AMD Ryzen 7 4800U (Renoir/Zen2) triggered by the SRSO (Speculative Return Stack Overflow) mitigation interacting with the scheduler tick path. The system crashes every 1-11 days with no user-space trigger. Crashes occur in both linux-image-7.0.0-22-generic and linux-image-7.0.0-27-generic. Workaround: processor.max_cstate=1 (preventing deep C-states avoids the crash path). == Hardware == - System: AZW (Beelink) SER Mini PC - CPU: AMD Ryzen 7 4800U with Radeon Graphics (Zen2 / Renoir) - Microcode: 0x0860010d (updated from 0x08600106 at boot) - GPU: AMD Renoir [Radeon Vega Series] (integrated, amdgpu driver) - RAM: 16GB DDR4 - BIOS: SER_V1.14_P3C6M43_B_Link (03/24/2022) — latest available for this model - NVMe storage == Software == - Ubuntu 26.04 LTS (fresh install on 2026-05-26) - Kernel: 7.0.0-22-generic and 7.0.0-27-generic (both affected) - amd64-microcode: 3.20251202.1ubuntu2 - linux-firmware: 20260319.git217ca6e4.1ubuntu - Boot params: quiet splash crashkernel=... - Active mitigation: srso_return_thunk (confirmed via dmesg) - NOPTI active == Crash #1 — 2026-07-10 (kernel 7.0.0-27) == Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 0 Comm: swapper/0 RIP: 0010:srso_safe_ret+0x0/0x20 Call Trace: <IRQ> sched_tick+0x48/0x280 update_process_times+0xa0/0xe0 tick_nohz_handler+0x96/0x1a0 __hrtimer_run_queues+0x10c/0x270 hrtimer_interrupt+0x104/0x250 __sysvec_apic_timer_interrupt+0x58/0x150 sysvec_apic_timer_interrupt+0x9a/0xd0 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1b/0x20 RIP: 0010:cpuidle_enter_state+0xca/0x700 cpuidle_enter+0x30/0x50 cpuidle_idle_call+0x16b/0x1f0 do_idle+0x94/0xf0 </TASK> == Crash #2 — 2026-07-12 (kernel 7.0.0-27) == BUG: unable to handle page fault for address: ffffffff99053b04 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD bc447067 P4D bc447067 PUD bc448063 PMD 0 Oops: Oops: 0002 [#1] SMP NOPTI CPU: 0 UID: 1000 PID: 2680076 Comm: curl RIP: 0010:kick_ilb+0x6e/0x180 Call Trace: <TASK> kick_ilb+0x52/0x180 nohz_balancer_kick+0x92/0x2d0 sched_balance_trigger+0x4c/0x90 sched_tick+0xf9/0x280 update_process_times+0xa0/0xe0 tick_nohz_handler+0x96/0x1a0 __hrtimer_run_queues+0x10c/0x270 hrtimer_interrupt+0x104/0x250 __sysvec_apic_timer_interrupt+0x58/0x150 sysvec_apic_timer_interrupt+0x44/0xd0 asm_sysvec_apic_timer_interrupt+0x1b/0x20 </TASK> == Additional context == - amdgpu driver logs "dm_irq_work_func [amdgpu] hogged CPU for >13333us" 35+ times per boot, suggesting IRQ pressure on the scheduler tick path. - Both crashes occur on CPU 0 during timer interrupt → sched_tick. - Crash #1 is an invalid opcode in the SRSO safe_ret thunk itself. - Crash #2 is a page fault in kick_ilb writing to an unmapped kernel address (PMD 0), suggesting corrupted per-cpu data or text patching issue in the SRSO path. - The system was stable for 14 days once (when amdgpu initialized without errors). - Full kdump vmcores are available in /var/crash/ for all crashes. == Crash frequency == 6+ crashes since 2026-05-29, intervals ranging from 1.5 to 11 days. No specific user-space trigger identified — crashes happen during idle or light workloads (cron jobs, curl). == Workaround == Adding processor.max_cstate=1 to kernel boot parameters prevents the CPU from entering deep C-states where the crash occurs. This confirms the interaction between cpuidle exit path, SRSO return thunks, and sched_tick. == Possible root cause == The SRSO mitigation (srso_return_thunk / srso_safe_ret) appears to have a bug in the text patching or in the interaction with the scheduler's nohz/idle balancer on AMD Zen2 processors when exiting deep C-states. The amdgpu driver hogging the CPU in interrupt context likely increases the probability of hitting the race condition. == Kdump files == /var/crash/202607101059/ — Crash #1 (srso_safe_ret) /var/crash/202607120124/ — Crash #2 (kick_ilb) Both contain full vmcore dumps and dmesg extracts. 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: 2.34.0-0ubuntu2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: gdm-greeter 2490 F.... wireplumber /dev/snd/controlC0: gdm-greeter 2490 F.... wireplumber /dev/snd/seq: gdm-greeter 2474 F.... pipewire CasperMD5CheckResult: unknown Date: Sun Jul 12 12:34:59 2026 InstallationDate: Installed on 2026-05-26 (47 days ago) InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1) IwDevWlp2s0Link: Not connected. MachineType: AZW SER ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=screen-256color ProcFB: 0 amdgpudrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-27-generic root=UUID=3cc618bf-7287-4c56-86b6-9ddbfe59a14a 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: 03/24/2022 dmi.bios.release: 5.16 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: SER_V1.14_P3C6M43_B_Link dmi.board.asset.tag: Default string dmi.board.name: SER dmi.board.vendor: AZW dmi.board.version: V01 dmi.chassis.asset.tag: Default string dmi.chassis.type: 35 dmi.chassis.vendor: AZW dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrSER_V1.14_P3C6M43_B_Link:bd03/24/2022:br5.16:svnAZW:pnSER:pvrDefaultstring:rvnAZW:rnSER:rvrV01:cvnAZW:ct35:cvrDefaultstring:skuSKU4:pfaSER: dmi.product.family: SER dmi.product.name: SER dmi.product.sku: SKU4 dmi.product.version: Default string dmi.sys.vendor: AZW To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2160457/+subscriptions

[Bug 2161904] [NEW] i915 backlight brightness control broken on ThinkPad T470 after kernel 7.0.0-28 (works on -27)

Public bug reported: Backlight brightness control stopped working after upgrading from kernel 7.0.0-27 to 7.0.0-28 on ThinkPad T470 (Intel HD Graphics 620). The KDE brightness OSD appears and F5/F6 keys respond, but the actual screen brightness does not change. Writing directly to /sys/class/backlight/intel_backlight/brightness has no effect either. Booting back into 7.0.0-27 restores full brightness control. Only one backlight interface exists (intel_backlight, no acpi_video0). This appears to be an i915 regression in 7.0.0-28. A user with a ThinkPad X250 (also Intel HD Graphics) reported the identical issue on the Ubuntu Discourse forum, also resolved by reverting to 7.0.0-27: https://discourse.ubuntu.com/t/screen-brightness-using-kernel-7-0-0-28-on-lenovo-thinkpad-x250-intel-hd-graphics/85267 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 AlsaVersion: Advanced Linux Sound Architecture Driver Version k7.0.0-27-generic. AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: joel 2850 F.... pipewire joel 2861 F.... wireplumber /dev/snd/pcmC0D0p: joel 2850 F...m pipewire /dev/snd/seq: joel 2850 F.... pipewire CRDA: N/A Card0.Amixer.info: Error: [Errno 2] No such file or directory: 'amixer' Card0.Amixer.values: Error: [Errno 2] No such file or directory: 'amixer' CasperMD5CheckResult: pass CurrentDesktop: KDE Date: Mon Jul 27 11:57:16 2026 InstallationDate: Installed on 2026-07-02 (25 days ago) InstallationMedia: Ubuntu-Server 26.04 "Resolute Raccoon" - Release amd64 (20260420.1) MachineType: LENOVO 20JNS28G00 ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-27-generic root=/dev/mapper/vg0-lv--0 ro crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. RfKill: Error: [Errno 2] No such file or directory: 'rfkill' SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 11/05/2024 dmi.bios.release: 1.79 dmi.bios.vendor: LENOVO dmi.bios.version: N1QETA4W (1.79 ) dmi.board.asset.tag: Not Available dmi.board.name: 20JNS28G00 dmi.board.vendor: LENOVO dmi.board.version: SDK0J40697 WIN dmi.chassis.asset.tag: PE03BQ37 dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.ec.firmware.release: 1.36 dmi.modalias: dmi:bvnLENOVO:bvrN1QETA4W(1.79):bd11/05/2024:br1.79:efr1.36:svnLENOVO:pn20JNS28G00:pvrThinkPadT470W10DG:rvnLENOVO:rn20JNS28G00:rvrSDK0J40697WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_20JN_BU_Think_FM_ThinkPadT470W10DG:pfaThinkPadT470W10DG: dmi.product.family: ThinkPad T470 W10DG dmi.product.name: 20JNS28G00 dmi.product.sku: LENOVO_MT_20JN_BU_Think_FM_ThinkPad T470 W10DG dmi.product.version: ThinkPad T470 W10DG dmi.sys.vendor: LENOVO ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug resolute wayland-session -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2161904 Title: i915 backlight brightness control broken on ThinkPad T470 after kernel 7.0.0-28 (works on -27) Status in linux package in Ubuntu: New Bug description: Backlight brightness control stopped working after upgrading from kernel 7.0.0-27 to 7.0.0-28 on ThinkPad T470 (Intel HD Graphics 620). The KDE brightness OSD appears and F5/F6 keys respond, but the actual screen brightness does not change. Writing directly to /sys/class/backlight/intel_backlight/brightness has no effect either. Booting back into 7.0.0-27 restores full brightness control. Only one backlight interface exists (intel_backlight, no acpi_video0). This appears to be an i915 regression in 7.0.0-28. A user with a ThinkPad X250 (also Intel HD Graphics) reported the identical issue on the Ubuntu Discourse forum, also resolved by reverting to 7.0.0-27: https://discourse.ubuntu.com/t/screen-brightness-using-kernel-7-0-0-28-on-lenovo-thinkpad-x250-intel-hd-graphics/85267 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 AlsaVersion: Advanced Linux Sound Architecture Driver Version k7.0.0-27-generic. AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: joel 2850 F.... pipewire joel 2861 F.... wireplumber /dev/snd/pcmC0D0p: joel 2850 F...m pipewire /dev/snd/seq: joel 2850 F.... pipewire CRDA: N/A Card0.Amixer.info: Error: [Errno 2] No such file or directory: 'amixer' Card0.Amixer.values: Error: [Errno 2] No such file or directory: 'amixer' CasperMD5CheckResult: pass CurrentDesktop: KDE Date: Mon Jul 27 11:57:16 2026 InstallationDate: Installed on 2026-07-02 (25 days ago) InstallationMedia: Ubuntu-Server 26.04 "Resolute Raccoon" - Release amd64 (20260420.1) MachineType: LENOVO 20JNS28G00 ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-27-generic root=/dev/mapper/vg0-lv--0 ro crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon. RfKill: Error: [Errno 2] No such file or directory: 'rfkill' SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 11/05/2024 dmi.bios.release: 1.79 dmi.bios.vendor: LENOVO dmi.bios.version: N1QETA4W (1.79 ) dmi.board.asset.tag: Not Available dmi.board.name: 20JNS28G00 dmi.board.vendor: LENOVO dmi.board.version: SDK0J40697 WIN dmi.chassis.asset.tag: PE03BQ37 dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.ec.firmware.release: 1.36 dmi.modalias: dmi:bvnLENOVO:bvrN1QETA4W(1.79):bd11/05/2024:br1.79:efr1.36:svnLENOVO:pn20JNS28G00:pvrThinkPadT470W10DG:rvnLENOVO:rn20JNS28G00:rvrSDK0J40697WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_20JN_BU_Think_FM_ThinkPadT470W10DG:pfaThinkPadT470W10DG: dmi.product.family: ThinkPad T470 W10DG dmi.product.name: 20JNS28G00 dmi.product.sku: LENOVO_MT_20JN_BU_Think_FM_ThinkPad T470 W10DG dmi.product.version: ThinkPad T470 W10DG dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161904/+subscriptions