This seems to be the same problem reported here: https://bugzilla.redhat.com/show_bug.cgi?id=1506339
** Bug watch added: Red Hat Bugzilla #1506339 https://bugzilla.redhat.com/show_bug.cgi?id=1506339 -- 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/1884546 Title: Lenovo T440s hangs on the dock when unsleeping the monitor Status in linux package in Ubuntu: Incomplete Bug description: This issue has been a persistent but infrequent problem for many years with the T440s. It only occurs when the laptop is docked. I have reported this bug several times. However, with the current kernel release, 5.4.0-37, this occurs at least once a day. The kern.log lines are: Jun 21 16:44:23 magpie kernel: [13992.853712] [drm:intel_set_cpu_fifo_underrun_r eporting [i915]] *ERROR* uncleared fifo underrun on pipe B Jun 21 16:44:23 magpie kernel: [13992.853749] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun Jun 21 17:17:00 magpie kernel: [15950.119066] [drm:intel_set_cpu_fifo_underrun_reporting [i915]] *ERROR* uncleared fifo underrun on pipe B Jun 21 17:17:00 magpie kernel: [15950.119101] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ followed by a dead hang. The pattern is the same each time. My current work around is to use the previous version of the released kernel, 5.4.0-33, which does not have this issue. I'm hoping someone has an idea. It's very frustrating. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-37-generic 5.4.0-37.41 ProcVersionSignature: Ubuntu 5.4.0-37.41-generic 5.4.41 Uname: Linux 5.4.0-37-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC2: weinberg 3505 F.... pulseaudio /dev/snd/controlC1: weinberg 3505 F.... pulseaudio /dev/snd/controlC0: weinberg 3505 F.... pulseaudio CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Mon Jun 22 10:02:42 2020 EcryptfsInUse: Yes HibernationDevice: RESUME=UUID=8d33a538-4ec4-418d-b277-be1a9a1c1113 InstallationDate: Installed on 2018-03-12 (832 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20180114) MachineType: LENOVO 20ARA0S100 ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-37-generic root=UUID=b6683bc1-7dd5-4afd-8e70-f69253403b71 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-5.4.0-37-generic N/A linux-backports-modules-5.4.0-37-generic N/A linux-firmware 1.187 SourcePackage: linux UpgradeStatus: Upgraded to focal on 2020-04-24 (58 days ago) dmi.bios.date: 03/19/2014 dmi.bios.vendor: LENOVO dmi.bios.version: GJET74WW (2.24 ) dmi.board.asset.tag: Not Available dmi.board.name: 20ARA0S100 dmi.board.vendor: LENOVO dmi.board.version: Not Defined dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Not Available dmi.modalias: dmi:bvnLENOVO:bvrGJET74WW(2.24):bd03/19/2014:svnLENOVO:pn20ARA0S100:pvrThinkPadT440s:rvnLENOVO:rn20ARA0S100:rvrNotDefined:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.family: ThinkPad T440s dmi.product.name: 20ARA0S100 dmi.product.sku: LENOVO_MT_20AR_BU_Think_FM_ThinkPad T440s dmi.product.version: ThinkPad T440s dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1884546/+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
