Thank you for reporting this bug to Ubuntu. Ubuntu 18.10 (cosmic) reached end-of-life on July 18, 2019.
See this document for currently supported Ubuntu releases: https://wiki.ubuntu.com/Releases We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in and change the bug status to Confirmed. ** Changed in: mutter (Ubuntu) Status: New => Won't Fix ** Changed in: linux (Ubuntu) Status: Incomplete => Won't Fix -- 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/1802573 Title: Thinkpad x220 - Unable to use 2560x1440 external display connected via DisplayPort due flashing black screen Status in linux package in Ubuntu: Won't Fix Status in mutter package in Ubuntu: Won't Fix Bug description: I have a fresh install of 18.10 on an old Thinkpad x220. Everything works fine with the internal display or an external Dell G2410 (1920x1080) connected via VGA. But when I try to switch to an external BenQ PD2710QC (2560x1440) I only see the screen for a few seconds at a time and then it flashes to black. This happens consistently for minutes--it never "settles down". I've tried the default configuration as well as copying xorg.conf from /usr/share/doc/xserver-xorg-video-intel into /etc/x11. I've tried both xorg configurations with nomodeset in the bootloader and without. I have not been able to find any configuration that allows this external DisplayPort display to work. The same hardware combination works fine in Windows 10. ProblemType: Bug DistroRelease: Ubuntu 18.10 Package: xorg 1:7.7+19ubuntu8 ProcVersionSignature: Ubuntu 4.18.0-10.11-generic 4.18.12 Uname: Linux 4.18.0-10-generic x86_64 ApportVersion: 2.20.10-0ubuntu13 Architecture: amd64 Date: Fri Nov 9 13:10:59 2018 DistUpgraded: Fresh install DistroCodename: cosmic DistroVariant: ubuntu ExtraDebuggingInterest: Yes GraphicsCard: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0126] (rev 09) (prog-if 00 [VGA controller]) Subsystem: Lenovo 2nd Generation Core Processor Family Integrated Graphics Controller [17aa:21da] InstallationDate: Installed on 2018-11-09 (0 days ago) InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.3) MachineType: LENOVO 42872WU ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.18.0-10-generic root=UUID=cd4f21be-48dd-48e7-b289-a59a32bd0be3 ro quiet splash nomodeset vt.handoff=1 SourcePackage: xorg Symptom: display UpgradeStatus: No upgrade log present (probably fresh install) XorgConf: Section "Device" Identifier "Intel" Driver "intel" # Option "AccelMethod" "uxa" EndSection dmi.bios.date: 06/21/2018 dmi.bios.vendor: LENOVO dmi.bios.version: 8DET76WW (1.46 ) dmi.board.asset.tag: Not Available dmi.board.name: 42872WU 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:bvr8DET76WW(1.46):bd06/21/2018:svnLENOVO:pn42872WU:pvrThinkPadX220:rvnLENOVO:rn42872WU:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.family: ThinkPad X220 dmi.product.name: 42872WU dmi.product.version: ThinkPad X220 dmi.sys.vendor: LENOVO version.compiz: compiz 1:0.9.13.1+18.10.20180930-0ubuntu1 version.libdrm2: libdrm2 2.4.95-1 version.libgl1-mesa-dri: libgl1-mesa-dri 18.2.2-0ubuntu1 version.libgl1-mesa-glx: libgl1-mesa-glx N/A version.xserver-xorg-core: xserver-xorg-core 2:1.20.1-3ubuntu2.1 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.1.0-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1ubuntu1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-3 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1802573/+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