Just a follow up with my investigations in the issue, that might be useful for users in a similar situation.
The problem related to grub not loading and fans lifting with no tomorrow is related to Thunderbolt. If I leave any kind of device (network adapter, webcam, whatever) attached to any of the two Thunderbolt ports, then any kind of boot (or reboot) will likely fail like I described above. While looking for solutions, I got into the certification page of my laptop [1] and saw that it says: "This system was tested with 18.04 LTS, running the 4.15.0-1059-oem kernel." Now, this kernel is not present in 20.04, but I've installed 5.6.0-1008-oem and despite of the certification, nothing changes at all. So, the state of things right now: - If I want to be sure the system will load grub, then nothing should be connected to the Thunderbolt port; - If I want to use HDMI output I MUST set "Discrete" (and not "Hybrid") in the BIOS for the display adapter; - If I want GDM/LightDM/Whatsoever to be loaded than the laptop lid should be left open until the end of the boot process, otherwise a blank screen with a single cursor (and a concert of fans) will be the only thing you'll have; Note that this counts for ANY kind of Thunderbolt setting I set inside the BIOS, so likely to be a Grub/EFI compatibility issue, but I have no more clue for now. With this kind of problems I think that writing this laptop is certified by Ubuntu seems ridiculous. I'm available for any kind of suggestions/proposal you have. [1] https://certification.ubuntu.com/hardware/201906-27150 -- 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/1876741 Title: Lenovo X1 boot crash with HDMI cable attached and laptop lid closed Status in linux package in Ubuntu: Confirmed Bug description: Hey everyone, just upgraded to 20.04 in my Lenovo X1 Carbon laptop and found myself in really big troubles. I always started my laptop pressing the power button and then closing the laptop lid, because I'm using an external HDMI display. This worked always well with Ubuntu 19.10. With 20.04 the system crash. These are the actions that reproduce the problem: 1 - Boot the system, pressing the power button and closing the laptop lid with an external HDMI display attached to the laptop; 2 - See on the external HDMI display the boot progress: BIOS loading and then grub not appearing; 3 - Listen to the fans that are about to make the laptop lift; 4 - Press the power button to force off the laptop; At this point the only way to have everything back is: 1 - Detach any external device; 2 - Detach the power cable; 3 - Wait 3 seconds or more; 4 - Open the laptop lid; 5 - Attach the power cable; 6 - Press the power button; Without doing exactly as I written the laptop will not boot up, even if I force power off, after starting it again, after the BIOS display, the screen goes blank and the fans lift. NOTE 1: I already disabled secure boot in the BIOS, and also selected discrete graphics for the display (otherwise I'm not able to even start X); NOTE 2: the scenario is exactly the same with nvidia-driver-435 and nvidia-driver-440; NOTE 3: if I leave the laptop lid open, everything is just fine; ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-28-generic 5.4.0-28.32 ProcVersionSignature: Ubuntu 5.4.0-28.32-generic 5.4.30 Uname: Linux 5.4.0-28-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC2: rasca 2750 F.... pulseaudio /dev/snd/controlC1: rasca 2750 F.... pulseaudio /dev/snd/controlC0: rasca 2750 F.... pulseaudio CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Mon May 4 16:24:47 2020 InstallationDate: Installed on 2019-12-10 (146 days ago) InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017) MachineType: LENOVO 20QVCTO1WW ProcFB: 0 EFI VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-28-generic root=UUID=c61df9cc-bd36-4ed2-8f52-de114bbf3fc3 ro rd.driver.blacklist=nouveau RelatedPackageVersions: linux-restricted-modules-5.4.0-28-generic N/A linux-backports-modules-5.4.0-28-generic N/A linux-firmware 1.187 SourcePackage: linux UpgradeStatus: Upgraded to focal on 2020-04-28 (6 days ago) dmi.bios.date: 03/24/2020 dmi.bios.vendor: LENOVO dmi.bios.version: N2OET43W (1.30 ) dmi.board.asset.tag: Not Available dmi.board.name: 20QVCTO1WW dmi.board.vendor: LENOVO dmi.board.version: SDK0T08861 WIN dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.modalias: dmi:bvnLENOVO:bvrN2OET43W(1.30):bd03/24/2020:svnLENOVO:pn20QVCTO1WW:pvrThinkPadX1Extreme2nd:rvnLENOVO:rn20QVCTO1WW:rvrSDK0T08861WIN:cvnLENOVO:ct10:cvrNone: dmi.product.family: ThinkPad X1 Extreme 2nd dmi.product.name: 20QVCTO1WW dmi.product.sku: LENOVO_MT_20QV_BU_Think_FM_ThinkPad X1 Extreme 2nd dmi.product.version: ThinkPad X1 Extreme 2nd dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1876741/+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
