(In reply to Johan Thorén from comment #19) > This error still occurs on kernel 4.20. > > My model is T470s and the behavior is consistent: It only happens when > connected to an external display through the dock, not when using it > disconnected from the dock. Can (most of the time) be triggered by changing > display settings through xrandr. > > Dock model is SD20F82750. > > Dmesg error message: > [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO > underrun > > GPU: Intel Corporation Skylake GT2 [HD Graphics 520] (rev 07)
The original bug is reported is on Broadwell. So, your issue could be different from the original issue reported in this bug. Can you please attach the full dmesg log from boot with kernel parameters drm.debug=0x1e log_buf_len=4M? What is the impact of this issue other than the error in the log? Can you elaborate the issue? -- 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: [Lenovo ThinkPad T450s] Issues after docking and locking: [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun Status in Linux: Incomplete Status in linux package in Ubuntu: Triaged Bug description: What happens is after I dock my laptop into a Lenovo ThinkPad Ultra Dock Type 40A2 20V, lock it via clicking the lock icon, and wait ~30 minutes, one of the following three things happen ~50% of the time when I come back to unlock it: * Most of the time the computer is found shut down. * Sometimes the notebook screen flickers weirdly and one of the two external monitors show pixelation. * The notebook screen shows the lock screen but is completely frozen. Occasionally unlocking works. I have two external monitors attached to the docking station. When I dock my laptop, the battery indicator does recognize its charging. I've not seen this issue when: 1) With the laptop in the dock, while actively using the laptop. 2) With the laptop out of the dock and no external monitors present. This bug started after upgrading from Ubtuntu 17.04 to Ubuntu 17.10. Using or not using the following kernel parameter didn't change anything: i915.enable_rc6=0 Updated docking station firmware to latest 2.33.00. PC temperatures are normal as per lm-sensors. 20171109 - Not reproducible testing drm-tip for 1.5 days. 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/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