Public bug reported: I have a Dell UP2414Q 24" 4K display panel. The only way to achieve 60Hz refresh on it, is to use DisplayPort 1.2 MST.
Due to MST, this results in two screens with 1920x2160 resolution being exposed to X. In order to get back to a proper rendering where it looks like a single display, one must either use Xinerama (with NVidia) or Xorg 3.18 and the new xrandr with support for configuring monitors in RandR 1.5 (with Intel). In both of these configurations, if the monitor itself is powered off, the output modes will disappear from xrandr, and when the monitor is powered back on, it behaves as though no output is being sent to it over the DisplayPort connection. When connecting with ssh to debug, running DISPLAY=:0 xrandr says that the two outputs exist, but no modes are configured, and indeed it does not list any. If however, instead of powering the monitor off, it is left on while away, this does not occur upon return, and the display works normally as when it was left. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: xorg 1:7.7+13ubuntu3 ProcVersionSignature: Ubuntu 4.4.0-12.28-generic 4.4.4 Uname: Linux 4.4.0-12-generic x86_64 .tmp.unity.support.test.0: ApportVersion: 2.20-0ubuntu3 Architecture: amd64 CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins' CompositorRunning: compiz CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0' CompositorUnredirectFSW: true CurrentDesktop: Unity Date: Sat Mar 12 12:26:16 2016 DistUpgraded: 2016-03-10 16:26:10,719 DEBUG failed to SystemUnLock() (E:Not locked) DistroCodename: xenial DistroVariant: ubuntu DkmsStatus: virtualbox, 5.0.16, 4.4.0-11-generic, x86_64: installed virtualbox, 5.0.16, 4.4.0-11-lowlatency, x86_64: installed virtualbox, 5.0.16, 4.4.0-12-generic, x86_64: installed virtualbox, 5.0.16, 4.4.0-12-lowlatency, x86_64: installed GraphicsCard: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller [8086:0412] (rev 06) (prog-if 00 [VGA controller]) Subsystem: Micro-Star International Co., Ltd. [MSI] Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller [1462:7919] InstallationDate: Installed on 2012-10-21 (1237 days ago) InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5) MachineType: MSI MS-7919 ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-12-generic root=UUID=167bf6e1-727f-4db1-b2f9-c496700b301b ro quiet splash vt.handoff=7 SourcePackage: xorg UpgradeStatus: Upgraded to xenial on 2016-03-10 (1 days ago) dmi.bios.date: 04/30/2014 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: V1.0 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: Z97M GAMING (MS-7919) dmi.board.vendor: MSI dmi.board.version: 1.0 dmi.chassis.asset.tag: To be filled by O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: MSI dmi.chassis.version: 1.0 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrV1.0:bd04/30/2014:svnMSI:pnMS-7919:pvr1.0:rvnMSI:rnZ97MGAMING(MS-7919):rvr1.0:cvnMSI:ct3:cvr1.0: dmi.product.name: MS-7919 dmi.product.version: 1.0 dmi.sys.vendor: MSI version.compiz: compiz 1:0.9.12.2+16.04.20160209-0ubuntu1 version.ia32-libs: ia32-libs N/A version.libdrm2: libdrm2 2.4.67-1 version.libgl1-mesa-dri: libgl1-mesa-dri 11.1.2-1ubuntu1 version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A version.libgl1-mesa-glx: libgl1-mesa-glx 11.1.2-1ubuntu1 version.xserver-xorg-core: xserver-xorg-core 2:1.18.1-1ubuntu4 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.1-1ubuntu2 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.6.1-1ubuntu2 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20160218-1ubuntu3 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2 xserver.bootTime: Sat Mar 12 11:07:14 2016 xserver.configfile: default xserver.devices: xserver.logfile: /var/log/Xorg.0.log xserver.outputs: xserver.version: 2:1.18.1-1ubuntu4 ** Affects: xorg (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug compiz-0.9 ubuntu xenial -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1556452 Title: 4K@60Hz DisplayPort 1.2 loses output modes Status in xorg package in Ubuntu: New Bug description: I have a Dell UP2414Q 24" 4K display panel. The only way to achieve 60Hz refresh on it, is to use DisplayPort 1.2 MST. Due to MST, this results in two screens with 1920x2160 resolution being exposed to X. In order to get back to a proper rendering where it looks like a single display, one must either use Xinerama (with NVidia) or Xorg 3.18 and the new xrandr with support for configuring monitors in RandR 1.5 (with Intel). In both of these configurations, if the monitor itself is powered off, the output modes will disappear from xrandr, and when the monitor is powered back on, it behaves as though no output is being sent to it over the DisplayPort connection. When connecting with ssh to debug, running DISPLAY=:0 xrandr says that the two outputs exist, but no modes are configured, and indeed it does not list any. If however, instead of powering the monitor off, it is left on while away, this does not occur upon return, and the display works normally as when it was left. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: xorg 1:7.7+13ubuntu3 ProcVersionSignature: Ubuntu 4.4.0-12.28-generic 4.4.4 Uname: Linux 4.4.0-12-generic x86_64 .tmp.unity.support.test.0: ApportVersion: 2.20-0ubuntu3 Architecture: amd64 CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins' CompositorRunning: compiz CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0' CompositorUnredirectFSW: true CurrentDesktop: Unity Date: Sat Mar 12 12:26:16 2016 DistUpgraded: 2016-03-10 16:26:10,719 DEBUG failed to SystemUnLock() (E:Not locked) DistroCodename: xenial DistroVariant: ubuntu DkmsStatus: virtualbox, 5.0.16, 4.4.0-11-generic, x86_64: installed virtualbox, 5.0.16, 4.4.0-11-lowlatency, x86_64: installed virtualbox, 5.0.16, 4.4.0-12-generic, x86_64: installed virtualbox, 5.0.16, 4.4.0-12-lowlatency, x86_64: installed GraphicsCard: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller [8086:0412] (rev 06) (prog-if 00 [VGA controller]) Subsystem: Micro-Star International Co., Ltd. [MSI] Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller [1462:7919] InstallationDate: Installed on 2012-10-21 (1237 days ago) InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5) MachineType: MSI MS-7919 ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-12-generic root=UUID=167bf6e1-727f-4db1-b2f9-c496700b301b ro quiet splash vt.handoff=7 SourcePackage: xorg UpgradeStatus: Upgraded to xenial on 2016-03-10 (1 days ago) dmi.bios.date: 04/30/2014 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: V1.0 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: Z97M GAMING (MS-7919) dmi.board.vendor: MSI dmi.board.version: 1.0 dmi.chassis.asset.tag: To be filled by O.E.M. dmi.chassis.type: 3 dmi.chassis.vendor: MSI dmi.chassis.version: 1.0 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrV1.0:bd04/30/2014:svnMSI:pnMS-7919:pvr1.0:rvnMSI:rnZ97MGAMING(MS-7919):rvr1.0:cvnMSI:ct3:cvr1.0: dmi.product.name: MS-7919 dmi.product.version: 1.0 dmi.sys.vendor: MSI version.compiz: compiz 1:0.9.12.2+16.04.20160209-0ubuntu1 version.ia32-libs: ia32-libs N/A version.libdrm2: libdrm2 2.4.67-1 version.libgl1-mesa-dri: libgl1-mesa-dri 11.1.2-1ubuntu1 version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A version.libgl1-mesa-glx: libgl1-mesa-glx 11.1.2-1ubuntu1 version.xserver-xorg-core: xserver-xorg-core 2:1.18.1-1ubuntu4 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.1-1ubuntu2 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.6.1-1ubuntu2 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20160218-1ubuntu3 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2 xserver.bootTime: Sat Mar 12 11:07:14 2016 xserver.configfile: default xserver.devices: xserver.logfile: /var/log/Xorg.0.log xserver.outputs: xserver.version: 2:1.18.1-1ubuntu4 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1556452/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp