I also can't boot the mainline 5.14-4 or 5.14-5 kernels on a Lenovo S7 (AMD 5800H and NVIDIA GPU) - it goes to a blank screen when trying to boot graphics and freezes - I can't open a tty and have to hard reset the system.
It looks like I have the laptop in the same mode as the other posters, ie hybrid/dynamic graphics mode using the amdgpu driver for the laptop screen. I can't see any relevant errors in the output "journalctl -b -1" for the failed boot - I think the hang occurs before it has a chance to log them. However, when booting the stock Ubuntu 21.10 5.13.0-16 kernel I do see some nvidia_drm RIP errors in the log in nv_drm_master_set(). Presumably these errors in combination with CONFIG_UBSAN_TRAP are causing the hang? The documentation says that in order to save around 5% of the kernel size, CONFIG_UBSAN_TRAP "reduces the kernel size overhead but turns all warnings (including potentially harmless conditions) into full exceptions that abort the running kernel code (regardless of context, locks held, etc), which may destabilize the system." It seems like a pretty aggressive config option to set! -- 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/1942684 Title: Kernel 5.14.X / 5.13.14 fails to boot Status in linux package in Ubuntu: Confirmed Bug description: I have been testing kernels 5.14.0 and 5.14.1 since their release on https://kernel.ubuntu.com/~kernel-ppa/mainline/ and my machine fails to boot with either one. However, I am able to boot just fine with 5.14.0-rc7. journalctl -b output attached with 5.14.1 Motherboard: MSI X570 Tomahawk CPU: AMD 5900X GPU: AsusTek 6800XT OS: Hirsute 21.04 --- ProblemType: Bug ApportVersion: 2.20.11-0ubuntu65.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME DistroRelease: Ubuntu 21.04 InstallationDate: Installed on 2021-07-04 (62 days ago) InstallationMedia: Ubuntu 21.04 "Hirsute Hippo" - Release amd64 (20210420) Package: linux (not installed) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash Tags: wayland-session hirsute Uname: Linux 5.14.0-051400rc6-generic x86_64 UnreportableReason: The running kernel is not an Ubuntu kernel UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin lxd plugdev sambashare sudo _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1942684/+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
