A victim of some other fix. This regression can be prevented by adding amdgpu.dc=0 to the kernel command line.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1762818 Title: Regression: Upgrading from 17.10 to 18.04 reduces resolution available on monitor Status in xorg package in Ubuntu: New Bug description: Symptom: booting 18.04 kernel reduces resolution available while 17.10 kernel (on 18.04) does not I have a 3 identical monitor setup - all at 2560x1600 native resolution. If I boot the current 18.04 kernel 4.15.0-13-generic then the third monitor does not have the native resolution available. If I reboot with the last 17.10 kernel 4.13.0-37-generic then all monitors have the native resolution available. On the video card the monitors are connected to HDMI, DisplayPort and DVI. On the monitors themselves the connectors are HDMI, DisplayPort and HDMI. (3rd monitor is using DVI to HDMI cable.) Xorg logs show identical EDID information between the kernels. 18.04's just decides to not make 2560x1600 available, having 2048x1080 or 1920x1200 as the highest. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: xorg 1:7.7+19ubuntu6 ProcVersionSignature: Ubuntu 4.15.0-13.14-generic 4.15.10 Uname: Linux 4.15.0-13-generic x86_64 ApportVersion: 2.20.9-0ubuntu4 Architecture: amd64 CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins' CompositorRunning: None CurrentDesktop: XFCE Date: Tue Apr 10 12:17:31 2018 DistUpgraded: 2018-03-31 12:24:30,098 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py' DistroCodename: bionic DistroVariant: ubuntu ExtraDebuggingInterest: Yes GraphicsCard: Advanced Micro Devices, Inc. [AMD/ATI] Baffin [Radeon RX 460] [1002:67ef] (rev e5) (prog-if 00 [VGA controller]) Subsystem: Gigabyte Technology Co., Ltd Baffin [Radeon RX 460/560D / Pro 450/455/460/560] [1458:230a] LightdmGreeterLogOld: ** Message: Starting lightdm-gtk-greeter 2.0.1 (Aug 7 2015, 01:24:18) ** Message: [Configuration] Reading file: /etc/lightdm/lightdm-gtk-greeter.conf.d/01_ubuntu.conf ** Message: [Configuration] Reading file: /etc/lightdm/lightdm-gtk-greeter.conf.d/30_xubuntu.conf ** Message: [Configuration] Reading file: /etc/lightdm/lightdm-gtk-greeter.conf upstart: indicator-application main process (1456) killed by TERM signal MachineType: Supermicro C7Z170-SQ ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-13-generic root=UUID=725712a6-f0e0-4da1-b3d1-746a233eb459 ro rootflags=subvol=@ SourcePackage: xorg Symptom: display UpgradeStatus: Upgraded to bionic on 2018-03-31 (9 days ago) dmi.bios.date: 12/19/2016 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 2.0 dmi.board.asset.tag: Default string dmi.board.name: C7Z170-SQ dmi.board.vendor: Supermicro dmi.board.version: 1.01A dmi.chassis.asset.tag: Default string dmi.chassis.type: 17 dmi.chassis.vendor: Supermicro dmi.chassis.version: 0123456789 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr2.0:bd12/19/2016:svnSupermicro:pnC7Z170-SQ:pvr0123456789:rvnSupermicro:rnC7Z170-SQ:rvr1.01A:cvnSupermicro:ct17:cvr0123456789: dmi.product.family: Default string dmi.product.name: C7Z170-SQ dmi.product.version: 0123456789 dmi.sys.vendor: Supermicro version.compiz: compiz N/A version.libdrm2: libdrm2 2.4.91-2 version.libgl1-mesa-dri: libgl1-mesa-dri 18.0.0~rc5-1ubuntu1 version.libgl1-mesa-glx: libgl1-mesa-glx 18.0.0~rc5-1ubuntu1 version.xserver-xorg-core: xserver-xorg-core 2:1.19.6-1ubuntu3 version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.5-1ubuntu1 version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:18.0.1-1 version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1 version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1762818/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
