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
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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
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