Alexander Kops, to advise, if the root cause problem is drm-intel (I'll let Kai-Heng Feng speak to this as the root cause since he asked you to test this), and this is confirmed an issue in the latest mainline kernel (which is now 4.14-rc8) then testing drm-intel makes sense.
This is due to how Ubuntu sources paches from mainline (not drm-intel), and some patches, but not necessarily all, are sent from drm-intel to mainline. Also, drm-intel is an experimental, fast changing tree, where some patches that don't and will never exist in mainline can be removed/added at any time. Despite this, while you did note the kernel crash as per #4, and the errors as per the Bug Description, you didn't include the log in its entirety, which would allow one to best confirm this is the root cause. I took a peak at the recent attachments, and while I'm not an expert, I didn't find better confirmation either way. Kai-Heng Feng, could you please advise on your thoughts regarding the root cause here? Would an SSH/netconsole dump be helpful here as per https://help.ubuntu.com/community/DebuggingSystemCrash, or you think enough information is available? -- 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/1727662 Title: Crashes after unlock: [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun Status in linux package in Ubuntu: Incomplete Bug description: After upgrading from Ubtuntu 17.04 to Ubuntu 17.10 this bug started appearing. When I lock my screen on my Lenovo T450s and the notebook sits in the dock (two external screens attached), one of the three things happen when I come back after some time and try to unlock (so it went to power save in-between): * Most of the time the computer was just shut down and I have to start it again * Sometimes the notebook screen flickers weirdly and one of the two other screens show pixel garbage * The notebook screen shows the lock screen but is completely frozen. Occasionally unlocking also works. The last thing I find in /var/log/syslog is [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun Using or not using the following kernel parameter didn't change anything: i915.enable_rc6=0 ProblemType: Bug DistroRelease: Ubuntu 17.10 Package: linux-image-4.13.0-16-lowlatency 4.13.0-16.19 ProcVersionSignature: Ubuntu 4.13.0-16.19-lowlatency 4.13.4 Uname: Linux 4.13.0-16-lowlatency x86_64 ApportVersion: 2.20.7-0ubuntu3 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: akops 3337 F.... pulseaudio /dev/snd/controlC0: akops 3337 F.... pulseaudio CurrentDesktop: ubuntu:GNOME Date: Thu Oct 26 10:44:11 2017 HibernationDevice: RESUME=/dev/mapper/system-swap_1 MachineType: LENOVO 20BWS2YL00 ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.13.0-16-lowlatency root=/dev/mapper/system-root ro quiet splash i915.enable_rc6=0 crashkernel=384M-:128M vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-4.13.0-16-lowlatency N/A linux-backports-modules-4.13.0-16-lowlatency N/A linux-firmware 1.169 SourcePackage: linux UpgradeStatus: Upgraded to artful on 2017-10-20 (5 days ago) dmi.bios.date: 07/08/2015 dmi.bios.vendor: LENOVO dmi.bios.version: JBET51WW (1.16 ) dmi.board.asset.tag: Not Available dmi.board.name: 20BWS2YL00 dmi.board.vendor: LENOVO dmi.board.version: SDK0E50510 WIN dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.modalias: dmi:bvnLENOVO:bvrJBET51WW(1.16):bd07/08/2015:svnLENOVO:pn20BWS2YL00:pvrThinkPadT450s:rvnLENOVO:rn20BWS2YL00:rvrSDK0E50510WIN:cvnLENOVO:ct10:cvrNone: dmi.product.family: ThinkPad T450s dmi.product.name: 20BWS2YL00 dmi.product.version: ThinkPad T450s dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1727662/+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
