[Bug 2157682] Re: iwlwifi AX211 Microcode SW error on kernel 7.0 (regression from 6.17 / Ubuntu 25.10)

** Attachment added: "Last crash log (journalctl -k -b -1)" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2157682/+attachment/5978147/+files/last-crash.txt -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2157682 Title: iwlwifi AX211 Microcode SW error on kernel 7.0 (regression from 6.17 / Ubuntu 25.10) Status in linux package in Ubuntu: New Bug description: SUMMARY iwlwifi (Intel Wi-Fi 6E AX211) firmware crashes repeatedly with "Microcode SW error detected. Restarting 0x0." on kernel 7.0 (Ubuntu 26.04 LTS). Regression: the same hardware was fully stable on Ubuntu 25.10 (kernel 6.17). The crash makes the machine unusable within minutes of normal use, and is reliably triggered by network activity (mainly fetching mail in Thunderbird on multiple accounts). HARDWARE - Laptop: Lenovo Yoga Slim 6 14IAP8 (machine type 82WU) - CPU: Intel Alder Lake (12th gen, hybrid) - Wi-Fi: Intel Wi-Fi 6E AX211 160MHz (PCI 0000:00:14.3)   - Detected crf-id 0x400410, cnv-id 0x80400 - BIOS: Lenovo KTCN39WW (2023-08-18) SOFTWARE - Ubuntu 26.04 LTS (upgraded from 25.10) - Affected kernels: 7.0.0-22-generic AND 7.0.0-15-generic   (both crash identically) - Wi-Fi firmware: 89.123cf747.0 so-a0-gf-a0-89.ucode (op_mode iwlmvm) - linux-firmware: 20260319.git217ca6e4.1ubuntu (latest available) CRASH SIGNATURE iwlwifi 0000:00:14.3: Microcode SW error detected. Restarting 0x0. WARNING: drivers/net/wireless/intel/iwlwifi/iwl-trans.h:1097   at iwl_pcie_irq_handle_error+0x1ba/0x200 [iwlwifi] iwlwifi 0000:00:14.3: Start IWL Error Log Dump: iwlwifi 0000:00:14.3: 0x00000B03 | IML/ROM error/state iwlwifi 0000:00:14.3: 0x60000000 | FSEQ_ERROR_CODE Also observed just before the crash: iwlwifi 0000:00:14.3: [0] Got MSI-X interrupt before we have Rx queues "REGRESSION" : SOME DETAILS - Ubuntu 25.10 with kernel 6.17.0-x: STABLE, no Wi-Fi crashes. - After upgrade to Ubuntu 26.04 (kernel 7.0.0-x): crashes within   minutes, every session. - Identical crash on both 7.0.0-15 and 7.0.0-22, so it is not   specific to a single 7.0 build. WORKAROUNDS TESTED (none resolved the crash) - intel_iommu=off : removed the accompanying DMAR/IOMMU faults from   the log, but the iwlwifi Microcode SW error still occurs. - iommu=pt : same result (DMAR faults gone, Wi-Fi crash remains). - modprobe options iwlwifi power_save=0 uapsd_disable=1 11n_disable=8 :   no effect on the crash. - Booting the older installed kernel (7.0.0-15): same crash. The DMAR/IOMMU faults therefore appear to be a side effect, not the root cause. The root cause is the iwlwifi/firmware initialization failure (IML/ROM error, FSEQ_ERROR_CODE) on the 7.0 kernel. EXPECTED Wi-Fi remains stable under normal use, as it did on kernel 6.17 (Ubuntu 25.10). ACTUAL Repeated iwlwifi microcode crashes, Wi-Fi drops and full system instability within minutes. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-22-generic 7.0.0-22.22 ProcVersionSignature: Ubuntu 7.0.0-22.22-generic 7.0.0 Uname: Linux 7.0.0-22-generic x86_64 ApportVersion: 2.34.0-0ubuntu2 Architecture: amd64 AudioDevicesInUse:  USER PID ACCESS COMMAND  /dev/snd/controlC0: nicolas 5182 F.... pipewire                       nicolas 5202 F.... wireplumber  /dev/snd/seq: nicolas 5182 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Sat Jun 20 03:38:54 2026 InstallationDate: Installed on 2025-02-06 (498 days ago) InstallationMedia: Ubuntu 24.10 "Oracular Oriole" - Release amd64 (20241009.4) MachineType: LENOVO 82WU ProcEnviron:  LANG=fr_FR.UTF-8  PATH=(custom, no user)  SHELL=/bin/bash  TERM=xterm-256color  XDG_RUNTIME_DIR=<set> ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-22-generic root=UUID=3b9eac6f-0152-405e-9800-5d424a52c8ed ro quiet splash iommu=off crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M SourcePackage: linux UpgradeStatus: Upgraded to resolute on 2026-05-19 (32 days ago) dmi.bios.date: 08/18/2023 dmi.bios.release: 1.39 dmi.bios.vendor: LENOVO dmi.bios.version: KTCN39WW dmi.board.asset.tag: NO Asset Tag dmi.board.name: LNVNB161216 dmi.board.vendor: LENOVO dmi.board.version: SDK0T76463 WIN dmi.chassis.asset.tag: NO Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Yoga Slim 6 14IAP8 dmi.ec.firmware.release: 1.39 dmi.modalias: dmi:bvnLENOVO:bvrKTCN39WW:bd08/18/2023:br1.39:efr1.39:svnLENOVO:pn82WU:pvrYogaSlim614IAP8:rvnLENOVO:rnLNVNB161216:rvrSDK0T76463WIN:cvnLENOVO:ct10:cvrYogaSlim614IAP8:skuLENOVO_MT_82WU_BU_idea_FM_YogaSlim614IAP8:pfaYogaSlim614IAP8: dmi.product.family: Yoga Slim 6 14IAP8 dmi.product.name: 82WU dmi.product.sku: LENOVO_MT_82WU_BU_idea_FM_Yoga Slim 6 14IAP8 dmi.product.version: Yoga Slim 6 14IAP8 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2157682/+subscriptions