** Description changed: Bug 1 - i915 HPD workqueue hard lockup (primary issue) With an HDMI monitor connected, the system hard locks at idle within minutes of booting. The kernel does not panic or produce an oops, it freezes completely with no further log output. kdump does not capture a vmcore, consistent with a hard CPU lockup occurring too fast for the crash kernel to initialise. The following warning appears repeatedly in the journal before the crash: workqueue: i915_hpd_poll_init_work [i915] hogged CPU for >10000us 4 times, consider switching to WQ_UNBOUND workqueue: i915_hpd_poll_init_work [i915] hogged CPU for >10000us 5 times, consider switching to WQ_UNBOUND Shortly before the crash: gnome-shell: Cursor update failed: drmModeAtomicCommit: Invalid argument Physically unplugging the HDMI cable also triggers an immediate hard crash, indicating the bug is in the interrupt-driven HPD path as well as the polling loop. Note: modinfo i915 | grep hpd returns no results on this kernel build, there are no HPD-specific i915 module parameters exposed. + Additionally, the following i915 error appears at boot before any HPD + events occur: + + i915 0000:00:02.0: [drm] *ERROR* Failed to probe lspcon + + This suggests i915 display hardware initialisation is incomplete on this hardware + under kernel 6.17, which may be the root cause underlying both the lspcon and HPD + issues. + Workaround for Bug 1: Adding the following kernel parameters resolves the lockup: drm_kms_helper.poll=0 i915.enable_psr=0 i915.enable_dc=0 + Workaround for Bug 1: + Adding the following kernel parameters resolves the lockup: + + drm_kms_helper.poll=0 i915.enable_psr=0 i915.enable_dc=0 Bug 2 - SOF audio IPC storm on HDMI PCM streams (secondary issue) On the default kernel configuration, the SOF audio driver generates a continuous storm of IPC errors at boot targeting HDMI2 and HDMI3 PCM streams: sof-audio-pci-intel-cnl 0000:00:1f.3: NHLT table not found sof-audio-pci-intel-cnl 0000:00:1f.3: ipc tx error for 0x60010000 (msg/reply size: 108/20): -5 sof-audio-pci-intel-cnl 0000:00:1f.3: sof_ipc3_pcm_hw_params: pcm3 (HDMI2), dir 0: STREAM_PCM_PARAMS ipc failed for stream_tag 1 HDMI2: ASoC error (-5): at dpcm_fe_dai_hw_params() on HDMI2 The error repeats hundreds of times per boot. The missing NHLT ACPI table means the SOF driver cannot configure the HDMI audio streams. alsactl restore also fails with exit code 99 as a downstream consequence. Workaround for Bug 2: snd_intel_dspcfg.dsp_driver=1 This forces the legacy snd_hda_intel driver instead of SOF, which initialises cleanly on this hardware. - Full workaround - current working kernel parameters: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash snd_intel_dspcfg.dsp_driver=1 drm_kms_helper.poll=0 i915.enable_psr=0 i915.enable_dc=0" - Steps to reproduce Bug 1: 1. Boot Ubuntu 24.04.4 with kernel 6.17.0-20-generic on a Google Chromebox Ambassador 2. Connect a monitor via HDMI 3. Leave the system idle for 2-5 minutes 4. System hard locks with no kernel panic or oops captured Steps to reproduce Bug 2: 1. Boot Ubuntu 24.04.4 with kernel 6.17.0-20-generic on a Google Chromebox Ambassador 2. Check journal: journalctl -b | grep sof-audio 3. Hundreds of IPC error messages visible from boot quokka@quokka-Ambassador:~$ ProblemType: Bug DistroRelease: Ubuntu 24.04 Package: linux-image-6.17.0-20-generic 6.17.0-20.20~24.04.1 ProcVersionSignature: Ubuntu 6.17.0-20.20~24.04.1-generic 6.17.13 Uname: Linux 6.17.0-20-generic x86_64 ApportVersion: 2.28.1-0ubuntu3.8 Architecture: amd64 AudioDevicesInUse: - USER PID ACCESS COMMAND - /dev/snd/controlC0: quokka 2060 F.... wireplumber - /dev/snd/seq: quokka 2054 F.... pipewire + USER PID ACCESS COMMAND + /dev/snd/controlC0: quokka 2060 F.... wireplumber + /dev/snd/seq: quokka 2054 F.... pipewire CRDA: N/A CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Wed Apr 8 21:53:26 2026 InstallationDate: Installed on 2026-04-08 (0 days ago) InstallationMedia: Ubuntu 24.04.4 LTS "Noble Numbat" - Release amd64 (20260210) Lsusb: - Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub - Bus 001 Device 002: ID 046d:c52b Logitech, Inc. Unifying Receiver - Bus 001 Device 003: ID 8087:0026 Intel Corp. AX201 Bluetooth - Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub + Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub + Bus 001 Device 002: ID 046d:c52b Logitech, Inc. Unifying Receiver + Bus 001 Device 003: ID 8087:0026 Intel Corp. AX201 Bluetooth + Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub MachineType: Google Ambassador ProcEnviron: - LANG=en_US.UTF-8 - PATH=(custom, no user) - SHELL=/bin/bash - TERM=xterm-256color - XDG_RUNTIME_DIR=<set> + 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-6.17.0-20-generic root=UUID=edf1cdf1-f7a0-4bee-bd50-b4b07ac8c5b5 ro quiet splash snd_intel_dspcfg.dsp_driver=1 drm_kms_helper.poll=0 i915.enable_psr=0 i915.enable_dc=0 crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M vt.handoff=7 RelatedPackageVersions: - linux-restricted-modules-6.17.0-20-generic N/A - linux-backports-modules-6.17.0-20-generic N/A - linux-firmware 20240318.git3b128b60-0ubuntu2.25 + linux-restricted-modules-6.17.0-20-generic N/A + linux-backports-modules-6.17.0-20-generic N/A + linux-firmware 20240318.git3b128b60-0ubuntu2.25 SourcePackage: linux-hwe-6.17 UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 01/25/2026 dmi.bios.release: 0.0 dmi.bios.vendor: coreboot dmi.bios.version: MrChromebox-2512.2 dmi.board.name: Ambassador dmi.board.vendor: Google dmi.board.version: rev4 dmi.chassis.type: 35 dmi.chassis.vendor: Google dmi.ec.firmware.release: 0.0 dmi.modalias: dmi:bvncoreboot:bvrMrChromebox-2512.2:bd01/25/2026:br0.0:efr0.0:svnGoogle:pnAmbassador:pvrrev4:rvnGoogle:rnAmbassador:rvrrev4:cvnGoogle:ct35:cvr:skusku33554437: dmi.product.family: Google_Puff dmi.product.name: Ambassador dmi.product.sku: sku33554437 dmi.product.version: rev4 dmi.sys.vendor: Google
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2147571 Title: i915 HPD workqueue hard lockup and SOF audio IPC storm on Google Chromebox Ambassador with kernel 6.17.0-20-generic To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-hwe-6.17/+bug/2147571/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
