Same here, didn't occured before with 14.04, started immediatly with Xenial 16.04 fresh install
>From the syslog : May 11 18:29:10 hecatonchires kernel: [ 1.130925] [drm:intel_set_pch_fifo_underrun_reporting [i915]] *ERROR* uncleared pch fifo underrun on pch transcoder A May 11 18:29:10 hecatonchires kernel: [ 1.130974] [drm:intel_pch_fifo_underrun_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun $ cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=16.04 DISTRIB_CODENAME=xenial DISTRIB_DESCRIPTION="Ubuntu 16.04 LTS" $ uname -r -v -s Linux 4.4.0-22-generic #39-Ubuntu SMP Thu May 5 16:53:32 UTC 2016 $ sudo lspci -v -s 02.0 00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor Graphics Controller (rev 09) (prog-if 00 [VGA controller]) DeviceName: Onboard IGD Subsystem: ASUSTeK Computer Inc. P8 series motherboard Flags: bus master, fast devsel, latency 0, IRQ 28 Memory at f7800000 (64-bit, non-prefetchable) [size=4M] Memory at e0000000 (64-bit, prefetchable) [size=256M] I/O ports at f000 [size=64] Expansion ROM at <unassigned> [disabled] Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- Capabilities: [d0] Power Management version 2 Capabilities: [a4] PCI Advanced Features Kernel driver in use: i915 Kernel modules: i915 -- 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/1577099 Title: [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun Status in linux package in Ubuntu: Incomplete Bug description: Graphical glitches in Firefox. Gere is dmesg log when it happens. [97970.020983] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun [97970.021023] [drm:intel_pch_fifo_underrun_irq_handler [i915]] *ERROR* PCH transcoder A FIFO underrun Description: Ubuntu 16.04 LTS Release: 16.04 linux-image-generic: Установлен: 4.4.0.21.22 Кандидат: 4.4.0.21.22 ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.4.0-21-generic 4.4.0-21.37 ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6 Uname: Linux 4.4.0-21-generic x86_64 ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/pcmC0D0p: sam 2091 F...m pulseaudio /dev/snd/controlC0: sam 2091 F.... pulseaudio CurrentDesktop: Unity Date: Sun May 1 12:23:21 2016 HibernationDevice: RESUME=UUID=478fdfc2-ea5f-4e80-a404-cf3230067630 InstallationDate: Installed on 2016-04-16 (15 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Beta amd64 (20160415) MachineType: LENOVO 25372A2 ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-21-generic root=UUID=b5bacb2b-487f-4164-ba6f-e8d22ab6c97e ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-4.4.0-21-generic N/A linux-backports-modules-4.4.0-21-generic N/A linux-firmware 1.157 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 12/01/2011 dmi.bios.vendor: LENOVO dmi.bios.version: 6IET80WW (1.40 ) dmi.board.name: 25372A2 dmi.board.vendor: LENOVO dmi.board.version: Not Available dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Not Available dmi.modalias: dmi:bvnLENOVO:bvr6IET80WW(1.40):bd12/01/2011:svnLENOVO:pn25372A2:pvrThinkPadT410:rvnLENOVO:rn25372A2:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.name: 25372A2 dmi.product.version: ThinkPad T410 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1577099/+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