I determined that the problem was actually caused by updating the firmware on my Dell Latitude 7490 from version 1.7.2 to 1.9.3. So I believe this bug report can be closed.
-- 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/1831123 Title: USB input devices don't work with Dell WD15 dock Status in linux package in Ubuntu: Confirmed Bug description: A USB keyboard and mouse attached to a Dell WD15 USB-C dock stop working after undock/redock, requiring a reboot. Occasionally they fail to work from a cold boot. This was not a problem with the previous kernel 4.15.0-48. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-50-generic 4.15.0-50.54 ProcVersionSignature: Ubuntu 4.15.0-50.54-generic 4.15.18 Uname: Linux 4.15.0-50-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.6 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/pcmC2D0p: dbakken 2277 F...m pulseaudio /dev/snd/controlC2: dbakken 2277 F.... pulseaudio CurrentDesktop: KDE Date: Thu May 30 11:31:44 2019 InstallationDate: Installed on 2018-07-20 (314 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426) MachineType: Dell Inc. Latitude 7490 ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-50-generic root=UUID=bbf44790-b08f-4145-a990-6ae159421aa9 ro quiet splash vt.handoff=1 RelatedPackageVersions: linux-restricted-modules-4.15.0-50-generic N/A linux-backports-modules-4.15.0-50-generic N/A linux-firmware 1.173.6 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/26/2019 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.9.3 dmi.board.name: 0DJ6MJ dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.9.3:bd04/26/2019:svnDellInc.:pnLatitude7490:pvr:rvnDellInc.:rn0DJ6MJ:rvrA00:cvnDellInc.:ct10:cvr: dmi.product.family: Latitude dmi.product.name: Latitude 7490 dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1831123/+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
