[Bug 2164203] [NEW] iwlwifi regression causing iwlwifi to not load and severe IOMMU page faults and system stuttering during heavy traffic on Intel Wireless-AC 9560

Public bug reported: After upgrading to kernel version 7.0.0-30-generic,the wifi dissapears from my system and after manually loading iwlwifi system experiences severe micro-stutters and high CPU usage from systemd-journald during high-speed Wi-Fi downloads and speed tests. Looking at dmesg, the iwlwifi driver triggers thousands of recurring warnings:WARNING: drivers/iommu/dma-iommu.c:... iommu_dma_unmap_physiwl_pcie_irq_handler Hardware: Intel Corporation Cannon Lake PCH CNVi WiFi [8086:a370] (Wireless-AC 9560) Workaround used: Adding iommu=pt to GRUB_CMDLINE_LINUX_DEFAULT completely resolves the stutters, clears the dmesg errors, and stabilizes systemd-journald CPU usage. This indicates a regression in how the 7.0 kernel handles IOMMU DMA mapping/unmapping for this specific network module. Ubuntu 26.04 Lts ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-30-generic 7.0.0-30.30 ProcVersionSignature: Ubuntu 7.0.0-30.30-generic 7.0.12 Uname: Linux 7.0.0-30-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: ayan 1770 F.... wireplumber /dev/snd/controlC0: ayan 1770 F.... wireplumber /dev/snd/seq: ayan 1742 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Wed Aug 19 00:03:25 2026 InstallationDate: Installed on 2026-06-27 (52 days ago) InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1) MachineType: Micro-Star International Co., Ltd. GF65 Thin 9SD ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/usr/bin/zsh TERM=xterm-256color XDG_RUNTIME_DIR=<set> ProcFB: 0 nvidia-drmdrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-30-generic root=UUID=866c92aa-993c-4776-890e-5150d08f4aba ro quiet splash iommu=pt 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: 10/21/2021 dmi.bios.release: 1.12 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: E16W1IMS.10C dmi.board.asset.tag: Default string dmi.board.name: MS-16W1 dmi.board.vendor: Micro-Star International Co., Ltd. dmi.board.version: REV:1.0 dmi.chassis.asset.tag: Default string dmi.chassis.type: 10 dmi.chassis.vendor: Micro-Star International Co., Ltd. dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrE16W1IMS.10C:bd10/21/2021:br1.12:svnMicro-StarInternationalCo.,Ltd.:pnGF65Thin9SD:pvrREV1.0:rvnMicro-StarInternationalCo.,Ltd.:rnMS-16W1:rvrREV1.0:cvnMicro-StarInternationalCo.,Ltd.:ct10:cvrDefaultstring:sku16W1.1:pfaGF: dmi.product.family: GF dmi.product.name: GF65 Thin 9SD dmi.product.sku: 16W1.1 dmi.product.version: REV:1.0 dmi.sys.vendor: Micro-Star International Co., Ltd. ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug resolute wayland-session ** Attachment added: "lspci-vnvn.log" https://bugs.launchpad.net/bugs/2164203/+attachment/5993232/+files/lspci-vnvn.log -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2164203 Title: iwlwifi regression causing iwlwifi to not load and severe IOMMU page faults and system stuttering during heavy traffic on Intel Wireless-AC 9560 Status in linux package in Ubuntu: New Bug description: After upgrading to kernel version 7.0.0-30-generic,the wifi dissapears from my system and after manually loading iwlwifi system experiences severe micro-stutters and high CPU usage from systemd-journald during high-speed Wi-Fi downloads and speed tests. Looking at dmesg, the iwlwifi driver triggers thousands of recurring warnings:WARNING: drivers/iommu/dma-iommu.c:... iommu_dma_unmap_physiwl_pcie_irq_handler Hardware: Intel Corporation Cannon Lake PCH CNVi WiFi [8086:a370] (Wireless-AC 9560) Workaround used: Adding iommu=pt to GRUB_CMDLINE_LINUX_DEFAULT completely resolves the stutters, clears the dmesg errors, and stabilizes systemd-journald CPU usage. This indicates a regression in how the 7.0 kernel handles IOMMU DMA mapping/unmapping for this specific network module. Ubuntu 26.04 Lts ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-30-generic 7.0.0-30.30 ProcVersionSignature: Ubuntu 7.0.0-30.30-generic 7.0.12 Uname: Linux 7.0.0-30-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: ayan 1770 F.... wireplumber /dev/snd/controlC0: ayan 1770 F.... wireplumber /dev/snd/seq: ayan 1742 F.... pipewire CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Wed Aug 19 00:03:25 2026 InstallationDate: Installed on 2026-06-27 (52 days ago) InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1) MachineType: Micro-Star International Co., Ltd. GF65 Thin 9SD ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/usr/bin/zsh TERM=xterm-256color XDG_RUNTIME_DIR=<set> ProcFB: 0 nvidia-drmdrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-30-generic root=UUID=866c92aa-993c-4776-890e-5150d08f4aba ro quiet splash iommu=pt 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: 10/21/2021 dmi.bios.release: 1.12 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: E16W1IMS.10C dmi.board.asset.tag: Default string dmi.board.name: MS-16W1 dmi.board.vendor: Micro-Star International Co., Ltd. dmi.board.version: REV:1.0 dmi.chassis.asset.tag: Default string dmi.chassis.type: 10 dmi.chassis.vendor: Micro-Star International Co., Ltd. dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrE16W1IMS.10C:bd10/21/2021:br1.12:svnMicro-StarInternationalCo.,Ltd.:pnGF65Thin9SD:pvrREV1.0:rvnMicro-StarInternationalCo.,Ltd.:rnMS-16W1:rvrREV1.0:cvnMicro-StarInternationalCo.,Ltd.:ct10:cvrDefaultstring:sku16W1.1:pfaGF: dmi.product.family: GF dmi.product.name: GF65 Thin 9SD dmi.product.sku: 16W1.1 dmi.product.version: REV:1.0 dmi.sys.vendor: Micro-Star International Co., Ltd. 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