Alas! I spoke to seen. The seeming "workaround" only lasted for one boot, and after that, the ~180 seconds delay is back to stay, although the Intel IOMMU is still disabled.
So this issue is "sporadic". Maybe even a race condition... :( And maybe not even related to the intel-lpss driver: The line: "intel-lpss 0000:00:15.0: enabling device (0000 -> 0002)" seems to come from drivers/pci/setup-res.c: if (cmd != old_cmd) { dev_info(&dev->dev, "enabling device (%04x -> %04x)\n", old_cmd, cmd); pci_write_config_word(dev, PCI_COMMAND, cmd); } So it just enables the PCI device, which at some point leads to drivers/mfd/intel-lpss.c#intel_lpss_probe() being called which requests the DMA module leading to drivers/dma/idma64.c#idma64_probe() being called which finally outputs: dev_info(chip->dev, "Found Intel integrated DMA 64-bit\n"); So a lot of code between these two log lines: [ 6.439056] intel-lpss 0000:00:15.0: enabling device (0000 -> 0002) [ 187.141427] idma64 idma64.0: Found Intel integrated DMA 64-bit -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1973167 Title: linux-image-4.15.0-177-generic freezes on the welcome screen Status in linux package in Ubuntu: Confirmed Bug description: After updating to linux-image-4.15.0-177-generic, my machine completely freezes on the Ubuntu Welcome screen, i.e. right after switching to GUI mode. The mouse pointer is frozen, the keyboard does not even respond to CAPS LOCK or NUM LOCK, pressing CTRL+ALT+F2 shows no reaction. I cannot work with my machine at this point and have to hard reset it. Selecting advanced boot options in grub and selecting the previous linux kernel 4.15.0-176 makes it work again. So this bad bug was introduced with the 4.15.0-177 kernel release. I tried removing the nvidia-driver-510 package, presumably making Ubuntu use the "nouveau" driver, and with that, I could use the welcome screen and log in, but the machine still froze shortly afterwards. So maybe this is some sort of interference with my GeForce 1080 graphics card, but it is not specific to the driver used. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-177-generic:amd64 4.15.0-177.186 ProcVersionSignature: Ubuntu 4.15.0-176.185-generic 4.15.18 Uname: Linux 4.15.0-176-generic x86_64 NonfreeKernelModules: nvidia_drm nvidia_modeset nvidia ApportVersion: 2.20.9-0ubuntu7.27 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: robert 2082 F.... pulseaudio /dev/snd/controlC0: robert 2082 F.... pulseaudio /dev/snd/controlC2: robert 2082 F.... pulseaudio CurrentDesktop: Unity:Unity7:ubuntu Date: Thu May 12 13:36:28 2022 EcryptfsInUse: Yes InstallationDate: Installed on 2015-10-29 (2386 days ago) InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021) MachineType: Supermicro Super Server ProcFB: ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-176-generic root=UUID=7c296e4d-0189-43a0-aef8-7d536b98a536 ro RelatedPackageVersions: linux-restricted-modules-4.15.0-176-generic N/A linux-backports-modules-4.15.0-176-generic N/A linux-firmware 1.173.21 RfKill: SourcePackage: linux UpgradeStatus: Upgraded to bionic on 2019-07-29 (1017 days ago) dmi.bios.date: 09/18/2020 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 3.4 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: X11SAE dmi.board.vendor: Supermicro dmi.board.version: 1.01 dmi.chassis.asset.tag: To be filled by O.E.M. dmi.chassis.type: 17 dmi.chassis.vendor: Supermicro dmi.chassis.version: 0123456789 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr3.4:bd09/18/2020:svnSupermicro:pnSuperServer:pvr0123456789:rvnSupermicro:rnX11SAE:rvr1.01:cvnSupermicro:ct17:cvr0123456789: dmi.product.family: To be filled by O.E.M. dmi.product.name: Super Server dmi.product.version: 0123456789 dmi.sys.vendor: Supermicro To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1973167/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp