Display settings configures dual display resolution incorrectly

[Chris Anderson]

I have two displays side-by-side: one that is 2560x1440 in landscape and a second that is 1280x1024 in portrait. In earlier versions of Ubuntu (definitely in 18.04 and 19.10) I was able to configure this using Display Settings in the default windowing environment.

After upgrading to Ubuntu 20.04 it seems Display Settings is computing an incorrect horizontal resolution for the combined display. This results in a display that is too wide for the monitors that pans when I mouse toward the edges.

xrandr is reporting that it's trying to make a display that is 3840x1440 (2560+1280) instead of 3584x1440 (2560+1024), so I assume something is doing the math before considering the smaller display is in portrait instead of landscape.

here is the output from xrandr:

$ xrandr
Screen 0: minimum 8 x 8, current 3840 x 1440, maximum 16384 x 16384
DVI-I-0 disconnected (normal left inverted right x axis y axis)
DVI-I-1 connected 1024x1280+2560+0 left (normal left inverted right x axis y axis) 376mm x 301mm panning 1280x1280+2560+0 tracking 3840x1440+0+0 border 0/0/0/0
   1280x1024 60.02*+ 75.02
   1280x960 60.00
   1152x864 75.00
   1024x768 75.03 70.07 60.00
   800x600 75.00 72.19 60.32 56.25
   640x480 75.00 72.81 59.94
HDMI-0 disconnected (normal left inverted right x axis y axis)
DP-0 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 disconnected (normal left inverted right x axis y axis)
DP-4 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 597mm x 336mm panning 2816x1440+0+0 tracking 3840x1440+0+0 border 0/0/0/0
   2560x1440 59.95*+
   2048x1152 60.00
   1920x1200 59.88
   1920x1080 60.00 59.94 50.00 29.97 25.00 23.98
   1680x1050 59.95
   1600x1200 60.00
   1280x1024 75.02 60.02
   1280x720 60.00 59.94 50.00
   1200x960 59.90
   1152x864 75.00
   1024x768 75.03 60.00
   800x600 75.00 60.32
   720x576 50.00
   720x480 59.94
   640x480 75.00 59.94 59.93
DP-5 disconnected (normal left inverted right x axis y axis)

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30
Uname: Linux 5.4.0-29-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia wl
.proc.driver.nvidia.gpus.0000.01.00.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0000:01:00.0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 390.132 Fri Nov 1 00:40:14 PDT 2019
 GCC version: gcc version 9.3.0 (Ubuntu 9.3.0-10ubuntu2)
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Sun May 17 20:35:03 2020
DistUpgraded: 2020-04-24 00:21:43,329 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py'
DistroCodename: focal
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 NVIDIA Corporation GM200 [GeForce GTX 980 Ti] [10de:17c8] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. GM200 [GeForce GTX 980 Ti] [1043:8546]
InstallationDate: Installed on 2018-09-17 (608 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
MachineType: ASUS All Series
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-29-generic root=UUID=6f78923c-30a0-48fc-a273-9b33bfc359f0 ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: Upgraded to focal on 2020-04-24 (23 days ago)
dmi.bios.date: 04/18/2018
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 3503
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: Z97-PRO(Wi-Fi ac)
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr3503:bd04/18/2018:svnASUS:pnAllSeries:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnZ97-PRO(Wi-Fiac):rvrRev1.xx:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.family: ASUS MB
dmi.product.name: All Series
dmi.product.sku: All
dmi.product.version: System Version
dmi.sys.vendor: ASUS
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.101-2
version.libgl1-mesa-dri: libgl1-mesa-dri 20.0.4-2ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx 20.0.4-2ubuntu1
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.8-2ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1874217, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.