The current upstream resolution to this problem is https://git.kernel.org/linus/d341838d776a ("x86/PCI: Disable E820 reserved region clipping via quirks"), which relies on quirks that match DMI Vendor, Product Version, Product Name, and Board Name. This isn't an ideal solution because there are likely other systems we don't know about that need a similar fix.
The patch I'm attaching here is an experimental idea to work around this issue without the maintenance burden of the quirks. If anybody would be willing to test this patch, I would be very grateful. To test it, apply this patch to your kernel, boot with "pci=use_e820 efi=debug", and collect the dmesg log. ** Attachment added: "experimental patch to remove EfiMemoryMappedIO" https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe/+bug/1878279/+attachment/5632128/+files/remove-mmio -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-signed-hwe in Ubuntu. https://bugs.launchpad.net/bugs/1878279 Title: MSFT0004:00 06CB:CD98 Touchpad/trackpad mouse randomly not recognized from any given boot Status in Linux: Confirmed Status in Ubuntu: Confirmed Status in linux-signed-hwe package in Ubuntu: In Progress Status in linux-signed-hwe package in Fedora: New Bug description: Touchpad 'Buttonless Mylar surface multi-touch touchpad' doesn't work at all (No response from the Touchpad) for notebook 'Lenovo Ideapad 5 14IIL05 81YH' from first system start on. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-29-generic 5.4.0-29.33 ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30 Uname: Linux 5.4.0-29-generic x86_64 ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: tilman 1607 F.... pulseaudio CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Tue May 12 21:22:22 2020 InstallationDate: Installed on 2020-05-12 (0 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) MachineType: LENOVO 81YH ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/bin/bash ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-29-generic root=UUID=bb961a96-8855-4e50-814d-7994235377c3 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-5.4.0-29-generic N/A linux-backports-modules-5.4.0-29-generic N/A linux-firmware 1.187 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 03/25/2020 dmi.bios.vendor: LENOVO dmi.bios.version: DSCN23WW(V1.09) dmi.board.asset.tag: NO Asset Tag dmi.board.name: LNVNB161216 dmi.board.vendor: LENOVO dmi.board.version: No DPK dmi.chassis.asset.tag: NO Asset Tag dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: IdeaPad 5 14IIL05 dmi.modalias: dmi:bvnLENOVO:bvrDSCN23WW(V1.09):bd03/25/2020:svnLENOVO:pn81YH:pvrIdeaPad514IIL05:rvnLENOVO:rnLNVNB161216:rvrNoDPK:cvnLENOVO:ct10:cvrIdeaPad514IIL05: dmi.product.family: IdeaPad 5 14IIL05 dmi.product.name: 81YH dmi.product.sku: LENOVO_MT_81YH_BU_idea_FM_IdeaPad 5 14IIL05 dmi.product.version: IdeaPad 5 14IIL05 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1878279/+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
