Small update. I've gone back to try and see what I can learn from installing pre-built kernels:
1) for some reason when I reboot sometimes I see the grub screen in mirror mode and sometimes one monitor is blank. This issue happens whenever grub is mirrored between both monitors. It is always mirrored on cold boots. 2) I went back to older ubuntu kernel versions. (https://launchpad.net/ubuntu/bionic/+source/linux) I can confirm that the issue persists as far back as 4.15.0-18.19. I attempted 4.15.0-17.18, but the build files here: (https://launchpad.net/ubuntu/+source/linux/4.15.0-17.18, https://launchpad.net/~canonical-kernel- team/+archive/ubuntu/unstable/+build/14768117) do not include linux- modules-* and linux-modules-extra-*, and when I don't install those the monitor doesn't seem to be detected and there is no modeswitch after grub. I then went back to 4.15.0-18.17 and uninstalled linux-modules- extra-4.15.0-18.17 and found the same no monitor modeswitch problem. I will attempt to build 4.15.0-17.18 myself and see if I can get the modules to build and properly test, but this is very slow going at this point. Please let me know if there is another way to test that doesn't involve long builds. -- 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/1768139 Title: Kernel crash when booting laptop with hdmi monitor connected Status in linux package in Ubuntu: Incomplete Bug description: When I boot a Dell Inspiron 7559 with an external monitor connected to the hdmi port, it consistently shows only a blank screen after grub and I have to hard power off the laptop. I can see the following stack trace in journalctl: syslog contains: kernel: Missing switch case (6) in intel_prepare_dp_ddi_buffers This occurs with both a Dell U2515H using an HDMI cord, and a HP Compaq LA2405wg connected via HDMI-to-DVI adapter. WORKAROUND: Keep the monitor unplugged until the Ubuntu loading screen shows up. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-20-generic 4.15.0-20.21 ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 Uname: Linux 4.15.0-20-generic x86_64 ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Mon Apr 30 17:22:20 2018 InstallationDate: Installed on 2018-04-28 (2 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426) SourcePackage: linux-signed UpgradeStatus: No upgrade log present (probably fresh install) This is a fresh install. I have modified grub defaults to include "acpi_osi=!Windows 2015" --- ApportVersion: 2.20.9-0ubuntu7 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: apatterson 1965 F.... pulseaudio CurrentDesktop: ubuntu:GNOME DistroRelease: Ubuntu 18.04 HibernationDevice: RESUME=UUID=7b947b8e-de50-4ab6-b7f3-254a5dea924a InstallationDate: Installed on 2018-04-28 (9 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426) MachineType: Dell Inc. Inspiron 7559 Package: linux (not installed) ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-20-generic root=UUID=77f1cfec-1fe4-4201-9a91-9f00a5d7782b ro quiet splash "acpi_osi=!Windows 2015" ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17 RelatedPackageVersions: linux-restricted-modules-4.15.0-20-generic N/A linux-backports-modules-4.15.0-20-generic N/A linux-firmware 1.173 Tags: bionic wayland-session Uname: Linux 4.15.0-20-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dialout dip lpadmin plugdev sambashare sudo wireshark _MarkForUpload: True dmi.bios.date: 09/26/2017 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.2.5 dmi.board.name: 0H0CC0 dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.chassis.version: Not Specified dmi.modalias: dmi:bvnDellInc.:bvr1.2.5:bd09/26/2017:svnDellInc.:pnInspiron7559:pvr1.2.5:rvnDellInc.:rn0H0CC0:rvrA00:cvnDellInc.:ct10:cvrNotSpecified: dmi.product.family: Inspiron dmi.product.name: Inspiron 7559 dmi.product.version: 1.2.5 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1768139/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
