Current xenial linux-image-4.4.0-62-generic remains broken, with dmesg WARNs on CRTC clocks and then system hangs when switching user sessions (which invokes some gnome-session xrandr setup). Lost the exact dmesg on the system hang.
Current mainline 4.8.x (4.8.17-040817-generic) continues to behave nicely, although there's occasionally some delays when docking/undocking before the xrandr configuration updates. The 4.8 kernel is also included in the 16.04.02 HWE release, and a quick test with linux-image-4.8.0-36-generic seems to also behave reasonably well. I would tentatively consider this issue fixed in 16.04.02, although I still need to test with xserver-xorg-hwe-16.04. Will also test with the newest mainline 4.10 release when I have the chance. -- 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/1597267 Title: ThinkPad X260 connecting external DisplayPort hangs system Status in linux package in Ubuntu: Incomplete Bug description: Running Ubuntu 16.04 on a Lenovo ThinkPad X260 with Intel Skylake HD Graphics 520, connecting an external monitor to the DisplayPort connector causes the system to quickly hang. The system stops responding to network pings, cannot switch consoles, and needs a hard reboot. The external monitor does work when using a text console, and does not always hang in the LightDM login screen, but starting up a desktop session will always hang. This originally happened using a ThinkPad dock, and I tested it further using an external DP monitor. This happens on 4.4.0-28-generic as well as mainline 4.6.3-040603-generic and 4.7.0-040700rc5-generic; they all hang in a similar fashion. I have attached a journalctl log from running 4.7.0-040700rc5-generic and connecting the DP monitor while in a text console, before switching to the graphical console and logging in. The system hangs after a series of: kernel: WARNING: CPU: 3 PID: 2319 at /home/kernel/COD/linux/drivers/gpu/drm/i915/intel_pm.c:3647 skl_update_other_pipe_wm+0x15d/0x170 [i915] kernel: WARNING: CPU: 3 PID: 4418 at /home/kernel/COD/linux/drivers/gpu/drm/i915/intel_display.c:13957 skl_max_scale.part.108+0x69/0x70 [i915] kernel: [drm:gen8_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun The first warnings come immediately when connecting, and others when switching consoles and logging in. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: linux-image-4.4.0-28-generic 4.4.0-28.47 ProcVersionSignature: Ubuntu 4.4.0-28.47-generic 4.4.13 Uname: Linux 4.4.0-28-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: terom 1903 F.... pulseaudio CurrentDesktop: Unity Date: Wed Jun 29 13:03:18 2016 InstallationDate: Installed on 2016-06-26 (2 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1) MachineType: LENOVO 20F6007RGE ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-28-generic root=UUID=6636a3bb-262e-4ab2-ae81-d9388e3f7684 ro rootflags=subvol=@ quiet splash RelatedPackageVersions: linux-restricted-modules-4.4.0-28-generic N/A linux-backports-modules-4.4.0-28-generic N/A linux-firmware 1.157.1 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 06/01/2016 dmi.bios.vendor: LENOVO dmi.bios.version: R02ET48W (1.21 ) dmi.board.asset.tag: Not Available dmi.board.name: 20F6007RGE dmi.board.vendor: LENOVO dmi.board.version: SDK0J40705 WIN dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.modalias: dmi:bvnLENOVO:bvrR02ET48W(1.21):bd06/01/2016:svnLENOVO:pn20F6007RGE:pvrThinkPadX260:rvnLENOVO:rn20F6007RGE:rvrSDK0J40705WIN:cvnLENOVO:ct10:cvrNone: dmi.product.name: 20F6007RGE dmi.product.version: ThinkPad X260 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1597267/+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
