[Bug 2172971] [NEW] Hotplug doesnt work as expected

Public bug reported: Hotplugging as is or after adding grub parameter "intel_iommu=on" hotplug on drives stops working - unplugging works fine, the devices disappear without issue but when I hot plug them in, they do not always reappear back. Rebooting the machine restores the drives. Removing "intel_iommu=on" or using "intel_iommu=off" fixes the issue. In BIOS Hotplug and VMD were enabled. Since adding "intel_iommu=on" in grub has no effect, I assume it is on by default. Doing hotplug few times (even with wait time between the plugs) will cause the OS to hang completely requiring force reset. Another workaround is to add "iommu=pt". ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-42-generic 7.0.0-42.42 ProcVersionSignature: Ubuntu 7.0.0-42.42-generic 7.0.14 Uname: Linux 7.0.0-42-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/seq: user 34901 F.... pipewire CasperMD5CheckResult: pass Date: Wed Nov 4 15:56:24 2026 InstallationDate: Installed on 2026-11-04 (0 days ago) InstallationMedia: Ubuntu 26.04.1 LTS "Resolute Raccoon" - Release amd64 (20260826) MachineType: Intel Corporation BeechnutCity ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm XDG_RUNTIME_DIR=<set> ProcFB: 0 astdrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-42-generic root=UUID=f738f84f-7ae7-49c5-97e0-dab197e7a2bc ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M RfKill: SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 07/30/2024 dmi.bios.vendor: Intel Corporation dmi.bios.version: BHSDREL1.IPC.0034.D65.2407302228 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: BeechnutCity dmi.board.vendor: Intel Corporation dmi.board.version: 0.02 dmi.chassis.asset.tag: .................... dmi.chassis.type: 23 dmi.chassis.vendor: Intel Corporation dmi.chassis.version: ............ dmi.modalias: dmi:bvnIntelCorporation:bvrBHSDREL1.IPC.0034.D65.2407302228:bd07/30/2024:svnIntelCorporation:pnBeechnutCity:pvr....................:rvnIntelCorporation:rnBeechnutCity:rvr0.02:cvnIntelCorporation:ct23:cvr............:skuSKUNumber:pfaFamily: dmi.product.family: Family dmi.product.name: BeechnutCity dmi.product.sku: SKU Number dmi.product.version: .................... dmi.sys.vendor: Intel Corporation ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug resolute ** Attachment added: "Additional logs, platform information" https://bugs.launchpad.net/bugs/2172971/+attachment/6014910/+files/Ubuntu_26.04.1-2026.10.29.zip -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2172971 Title: Hotplug doesnt work as expected Status in linux package in Ubuntu: New Bug description: Hotplugging as is or after adding grub parameter "intel_iommu=on" hotplug on drives stops working - unplugging works fine, the devices disappear without issue but when I hot plug them in, they do not always reappear back. Rebooting the machine restores the drives. Removing "intel_iommu=on" or using "intel_iommu=off" fixes the issue. In BIOS Hotplug and VMD were enabled. Since adding "intel_iommu=on" in grub has no effect, I assume it is on by default. Doing hotplug few times (even with wait time between the plugs) will cause the OS to hang completely requiring force reset. Another workaround is to add "iommu=pt". ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: linux-image-7.0.0-42-generic 7.0.0-42.42 ProcVersionSignature: Ubuntu 7.0.0-42.42-generic 7.0.14 Uname: Linux 7.0.0-42-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/seq: user 34901 F.... pipewire CasperMD5CheckResult: pass Date: Wed Nov 4 15:56:24 2026 InstallationDate: Installed on 2026-11-04 (0 days ago) InstallationMedia: Ubuntu 26.04.1 LTS "Resolute Raccoon" - Release amd64 (20260826) MachineType: Intel Corporation BeechnutCity ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm XDG_RUNTIME_DIR=<set> ProcFB: 0 astdrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-42-generic root=UUID=f738f84f-7ae7-49c5-97e0-dab197e7a2bc ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M RfKill: SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 07/30/2024 dmi.bios.vendor: Intel Corporation dmi.bios.version: BHSDREL1.IPC.0034.D65.2407302228 dmi.board.asset.tag: Base Board Asset Tag dmi.board.name: BeechnutCity dmi.board.vendor: Intel Corporation dmi.board.version: 0.02 dmi.chassis.asset.tag: .................... dmi.chassis.type: 23 dmi.chassis.vendor: Intel Corporation dmi.chassis.version: ............ dmi.modalias: dmi:bvnIntelCorporation:bvrBHSDREL1.IPC.0034.D65.2407302228:bd07/30/2024:svnIntelCorporation:pnBeechnutCity:pvr....................:rvnIntelCorporation:rnBeechnutCity:rvr0.02:cvnIntelCorporation:ct23:cvr............:skuSKUNumber:pfaFamily: dmi.product.family: Family dmi.product.name: BeechnutCity dmi.product.sku: SKU Number dmi.product.version: .................... dmi.sys.vendor: Intel Corporation To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2172971/+subscriptions