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[Bug 1455598] Re: connecting 2x 4k displays in ubuntu 15.04 with daisy chain displayport (MST)

 

Hi, sorry it took a while, i wasn't home for a while.

I have some news to report;
- I've updates the bios to A08, 03/03/2015 (the output from dmidecode), but if i connect the laptop (with the laptopscreen enabled) to the 2x 4k screens, it just logs me out.
- I've found that if i disable the laptopscreen and try to use 2x 4k, it works!. Everything is really small though.. ;-)
- i was running ubuntu 14.10 and did an inplace upgrade. not sure if this is relevant
- a friend of mine is running the newer XPS13 and he has lots of problems connecting just one external monitor on 4k on ubuntu 15.04. I'm not sure its related, but i just wanted to say if it is, we can do some tests on that platvorm too. We also have an precision M3800 we could test.

What to do/test next?

** Changed in: xorg (Ubuntu)
       Status: Incomplete => New

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https://bugs.launchpad.net/bugs/1455598

Title:
  connecting 2x 4k displays in ubuntu 15.04 with daisy chain displayport
  (MST)

Status in xorg package in Ubuntu:
  New

Bug description:
  Hi,

  I own a Dell XPS12 (9Q33) and recently i have had 2 external monitors
  hooked to that through the (mini) display ports. The Screens are from
  the type Dell P2815Q. The screens have the ability to use Daisy chain
  (MST=>https://en.wikipedia.org/wiki/DisplayPort#Multiple_displays_on_single_DisplayPort_connector),
  but it fails if i connect my laptop with 2x 4k external monitors. If i
  try it, it shows me some quick lines of text and returnes me to the
  login screen. If i turn _off_ the secondairy screen, it does login
  with 1 external monitor at 4k. If i setup the resolution to 2x 2,5k on
  the external monitors, it does work. Both at the office (where there
  are as well 2 Dell monitors with 2,5k resolution (2500xsomething) but
  from a different type). I think the problem is with the 4k
  resolutions. The setup does work on Windows 8.1 Pro, so i can use my
  main screen at 1920x1080 as 2x 4k external screens (although its on
  30Hz, but thats due to the display port 1.2 specification i think). I
  haven't tried to connect the laptop with the main screen
  disabled/closed, so im gonna try that soon. But even if that works, i
  still think it's a bug as it seems to work on Windows.

  I've researched the fora, askbuntu, launchpad but i can't find a similar bug so i think i found one. I did find one thread that says it should work and is consistent with the MST working;
  - http://askubuntu.com/questions/369946/displayport-1-2-mst-daisy-chain-dual-monitor-setup-intel-graphics/401614#401614
  But i can't find anything similar with the 2x 4k resolution.

  Although i've tried, im a newbee at linux so excuse me if don't do
  stuff like it's supposed to. The ubuntu irc channel told me to use
  ubuntu-bug, so thats what i'm doing here. If i need to do things
  differenty, let me know.

  ProblemType: Bug
  DistroRelease: Ubuntu 15.04
  Package: xorg 1:7.7+7ubuntu4
  ProcVersionSignature: Ubuntu 3.19.0-16.16-generic 3.19.3
  Uname: Linux 3.19.0-16-generic x86_64
  .tmp.unity.support.test.0:
   
  ApportVersion: 2.17.2-0ubuntu1
  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: Fri May 15 19:43:43 2015
  DistUpgraded: 2015-04-23 21:52:13,436 DEBUG enabling apt cron job
  DistroCodename: vivid
  DistroVariant: ubuntu
  ExtraDebuggingInterest: Yes
  GraphicsCard:
   Intel Corporation Haswell-ULT Integrated Graphics Controller [8086:0a16] (rev 09) (prog-if 00 [VGA controller])
     Subsystem: Dell Device [1028:05e3]
  InstallationDate: Installed on 2015-03-04 (72 days ago)
  InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
  MachineType: Dell Inc. XPS 12-9Q33
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-16-generic root=UUID=8896779c-8f4d-4b4d-baae-5dd647d2572f ro quiet splash nomdmonddf nomdmonisw nomdmonddf nomdmonisw vt.handoff=7
  SourcePackage: xorg
  Symptom: display
  UpgradeStatus: Upgraded to vivid on 2015-04-23 (21 days ago)
  dmi.bios.date: 04/15/2014
  dmi.bios.vendor: Dell Inc.
  dmi.bios.version: A06
  dmi.board.name: XPS 12-9Q33
  dmi.board.vendor: Dell Inc.
  dmi.board.version: A06
  dmi.chassis.type: 8
  dmi.chassis.vendor: Dell Inc.
  dmi.chassis.version: Not Specified
  dmi.modalias: dmi:bvnDellInc.:bvrA06:bd04/15/2014:svnDellInc.:pnXPS12-9Q33:pvrA06:rvnDellInc.:rnXPS12-9Q33:rvrA06:cvnDellInc.:ct8:cvrNotSpecified:
  dmi.product.name: XPS 12-9Q33
  dmi.product.version: A06
  dmi.sys.vendor: Dell Inc.
  version.compiz: compiz 1:0.9.12.1+15.04.20150410.1-0ubuntu1
  version.ia32-libs: ia32-libs N/A
  version.libdrm2: libdrm2 2.4.60-2
  version.libgl1-mesa-dri: libgl1-mesa-dri 10.5.2-0ubuntu1
  version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
  version.libgl1-mesa-glx: libgl1-mesa-glx 10.5.2-0ubuntu1
  version.xserver-xorg-core: xserver-xorg-core 2:1.17.1-0ubuntu3
  version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.0-1ubuntu2
  version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.5.0-1ubuntu2
  version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917-1~exp1ubuntu2.1
  version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu2build1
  xserver.bootTime: Fri May 15 06:49:39 2015
  xserver.configfile: default
  xserver.errors: intel(0): sna_mode_check: invalid state found on pipe 1, disabling CRTC:23
  xserver.logfile: /var/log/Xorg.0.log
  xserver.outputs:
   product id                                1021 
   vendor                                     LGD
  xserver.version: 2:1.17.1-0ubuntu3

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