Connecting via HDMI rather than displayport has completely solved the waking issue for me (so far, at least). The monitor consistently wakes from sleep in the same configuration that I was using before suspending. Monitor settings are still not persistent across reboots, but this seems to be a more general issue that can be fixed via an appropriate startup script.
I have seen some reports of the U2415 having some problems with daisy- chaining via displayport and that Dell is giving people the runaround. Sounds like there is some flaw with the displayport, so perhaps we're seeing another effect of that. Will report back in case anything changes. -- 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/1412730 Title: DELL U2415 monitor detection issues Status in xorg package in Ubuntu: Confirmed Bug description: My Laptop HP Elitebook 8740w has two external screens connected. 1 DELL U2412M connected to vga connector 1 DELL U2415 connected to Displayport. I worked for about a year with a single external display, just U2412M on the displayport without the issue I decribe. The first issue: When booting up and with screens attatched and active, the 2415 boots in 1024x768 resolution, the 2412 boots at the same moment in 1920x1200 as it should. At the point where the login screen appears the 2415 goes in power save mode, most of the time. The 2412 displays just fine at the moment. After logging in, turning the 2415 off and on, sometimes helps the get the screen active (out of power save). When it gets active, the resoltion is 1024x768, not 1920x1200. In unity-control-center in display settings the 2415 is displayed as "Unknown Display" and the maximum resolution I can select is 1024x768. Second issue: After a laptop suspend the 2415 doenst alway become active again, the 2412 always. Turning off an on the 2415 multiple time mostly helps to get the screen active. Current partial workaround: xorg.conf with monitor section for 1920x1200 as in attatchment. This doesn't solve booting in 1024x768, but solves the resolution after logging in. unity-control-center still lists "Unknown Screen" Another strange behavior: when executing xrandr command, most of the time the 2415 stays in 1024, but after a number of executions the screen swithes to 1920x1200. At that moment xrandr outputs all possible resolutions as it should. When executing xrandr another time the 2415 switches back to 1024x768 Already tried kernel v3.18.3-vivid, no change. Also tried Utopic live cd, no change. Tried Windows 8.1, no issues with both screens. (however my main OS is Ubuntu trusty, so..., just for testing) ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: xorg 1:7.7+1ubuntu8 ProcVersionSignature: Ubuntu 3.13.0-44.73-generic 3.13.11-ckt12 Uname: Linux 3.13.0-44-generic x86_64 .tmp.unity.support.test.0: ApportVersion: 2.14.1-0ubuntu3.6 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 Date: Tue Jan 20 10:48:24 2015 DistUpgraded: Fresh install DistroCodename: trusty DistroVariant: ubuntu DkmsStatus: vboxhost, 4.3.20, 3.13.0-40-generic, x86_64: installed vboxhost, 4.3.20, 3.13.0-43-generic, x86_64: installed vboxhost, 4.3.20, 3.13.0-44-generic, x86_64: installed ExtraDebuggingInterest: Yes GraphicsCard: Advanced Micro Devices, Inc. [AMD/ATI] Broadway XT [Mobility Radeon HD 5870] [1002:68a0] (prog-if 00 [VGA controller]) Subsystem: Hewlett-Packard Company FirePro M7820 [103c:1520] InstallationDate: Installed on 2014-05-11 (253 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) MachineType: Hewlett-Packard HP EliteBook 8740w PccardctlStatus: Socket 0: 3.3V 16-bit PC Card Subdevice 0 (function 0) bound to driver "pata_pcmcia" ProcKernelCmdLine: BOOT_IMAGE=/@trusty/boot/vmlinuz-3.13.0-44-generic root=UUID=cfafe8f3-4766-4fc7-b6f3-857eefcd2aff ro rootflags=subvol=@trusty plymouth:debug splash quiet drm.debug=0xe radeon.audio=1 SourcePackage: xorg UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 07/07/2014 dmi.bios.vendor: Hewlett-Packard dmi.bios.version: 68CAD Ver. F.50 dmi.board.name: 1520 dmi.board.vendor: Hewlett-Packard dmi.board.version: KBC Version 33.31 dmi.chassis.asset.tag: CNU1152Q9W dmi.chassis.type: 10 dmi.chassis.vendor: Hewlett-Packard dmi.modalias: dmi:bvnHewlett-Packard:bvr68CADVer.F.50:bd07/07/2014:svnHewlett-Packard:pnHPEliteBook8740w:pvr:rvnHewlett-Packard:rn1520:rvrKBCVersion33.31:cvnHewlett-Packard:ct10:cvr: dmi.product.name: HP EliteBook 8740w dmi.sys.vendor: Hewlett-Packard version.compiz: compiz 1:0.9.11.3+14.04.20141104-0ubuntu1 version.ia32-libs: ia32-libs N/A version.libdrm2: libdrm2 2.4.56-1~ubuntu1 version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.3-0ubuntu0.2 version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.3-0ubuntu0.2 version.xserver-xorg-core: xserver-xorg-core 2:1.15.1-0ubuntu2.6 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu3.1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.910-0ubuntu1.3 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.10-1ubuntu2 xserver.bootTime: Tue Jan 20 09:37:08 2015 xserver.configfile: /etc/X11/xorg.conf xserver.errors: xserver.logfile: /var/log/Xorg.0.log xserver.version: 2:1.15.1-0ubuntu2.6 xserver.video_driver: radeon To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1412730/+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
