XrandR does not propose 21:9 resolution

[Sebastian]

If come here over bug 1895301 "XrandR does not propose 3440x1440 21:9 resolution".
In bug 1895301 sombody wrote "We just need one person experiencing the bug to open a bug with the relevant system details automatically attached." - so I did.

I have a similar problem with a 21:9 monitor with a resolution of 2560x1080. It's a LG 25UB55-B on a HP docking station A7E32A, DVI output with adapter to HDMI, HDMI cable and input to the monitor via HDMI. Laptop is an HP Elitebook 8440p (Intel i5-520 with Intel HD Graphics (ILK)), internal display with 1366*768 is in use as well.

I had Ubuntu 18.04 LTS before until January this year, with automatic updates on, so presumably up to date. There it worked fine out of the box, i.e. since first install I had the full resolution of 21:9 in 2560x1080 on my external monitor.

I didn't change any hardware, just installed Ubuntu 20.04 from DVD, an it stopped working.
I got only 16:9 with 1920x1080.
I've updated to Ubuntu 20.10, tried Ubuntu 21.04 (from DVD as well), changed cable and adapter, nothing helped.
Did some reseach with google and found the mentioned bug 1895301. The workaround worked, I got full resolution of 2560x1080 on the external display.
It is not permanent, so at the moment of filing this bug, I'm still back on the 16:9 with 1920x1080.

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: xorg 1:7.7+19ubuntu15
ProcVersionSignature: Ubuntu 5.8.0-53.60-generic 5.8.18
Uname: Linux 5.8.0-53-generic x86_64
ApportVersion: 2.20.11-0ubuntu50.6
Architecture: amd64
BootLog: Error: [Errno 13] Keine Berechtigung: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
CurrentDmesg: Error: command ['pkexec', 'dmesg'] failed with exit code 126: Error executing command as another user: Request dismissed
Date: Mon May 24 20:23:52 2021
DistUpgraded: 2021-05-23 15:18:23,444 ERROR got error from PostInstallScript ./xorg_fix_proprietary.py (g-exec-error-quark: Kindprozess »./xorg_fix_proprietary.py« konnte nicht ausgeführt werden (Datei oder Verzeichnis nicht gefunden) (8))
DistroCodename: groovy
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 02) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company Core Processor Integrated Graphics Controller [103c:172a]
InstallationDate: Installed on 2021-02-10 (103 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
MachineType: Hewlett-Packard HP EliteBook 8440p
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.8.0-53-generic root=/dev/mapper/vgubuntu-root ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: Upgraded to groovy on 2021-05-23 (1 days ago)
dmi.bios.date: 09/13/2013
dmi.bios.release: 15.36
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 68CCU Ver. F.24
dmi.board.name: 172A
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 30.34
dmi.chassis.asset.tag: CZC040C94D
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.ec.firmware.release: 48.52
dmi.modalias: dmi:bvnHewlett-Packard:bvr68CCUVer.F.24:bd09/13/2013:br15.36:efr48.52:svnHewlett-Packard:pnHPEliteBook8440p:pvr:rvnHewlett-Packard:rn172A:rvrKBCVersion30.34:cvnHewlett-Packard:ct10:cvr:
dmi.product.family: 103C_5336AN
dmi.product.name: HP EliteBook 8440p
dmi.product.sku: J2544631
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.102-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 20.2.6-0ubuntu0.20.10.1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.9-2ubuntu1.3
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200714-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1

[Sebastian (seb1024)]

As I said, the workaround worked. To help others looking for a solution and finding this bug, I will show it here for my configuration:

1.) Open a terminal

2.) Call xrandr to see, how your desired device is called. In my case, it's called "HDMI-1". If you have more than one, you may guess, but output should by clear enough.

3.) Call cvt with desired resolution and frequency. In my case it must be 2560x1080 with 30 (Hz), If you are unsure you have to try (I tried 60 Hz first - didn't work in the last step no. 6):

cvt 2560 1080 30

Output in my case is

# 2560x1080 29.97 Hz (CVT) hsync: 33.03 kHz; pclk: 106.75 MHz
Modeline "2560x1080_30.00" 106.75 2560 2640 2896 3232 1080 1083 1093 1102 -hsync +vsync

4.) Call xrandr to set new mode, copy everything after "Modeline":

xrandr --newmode "2560x1080_30.00" 106.75 2560 2640 2896 3232 1080 1083 1093 1102 -hsync +vsync

(The name in quotation marks could be changed, but no need to do so.)

5.) Call xrandr to add this mode by it's name to your desired device:

xrandr --addmode HDMI-1 2560x1080_30.00

6.) Call xrandr to set your desired device (here. HDMI-1) to the mode

xrandr --output HDMI-1 --mode 2560x1080_30.00

Instead of step 6 via terminal you could use the GUI to change the resolution, it should be there now.

Hope this may help somebody.

It is not persistent. I made a script and added it to autostart. There may be other ways, maybe a config file for xrandr?

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Daniel van Vugt (vanvugt)]

I have decoded your monitor's EDID and it does show the desired resolution but only as a "Detailed mode". So that would appear to make this a duplicate of bug 1901470.

EDID version: 1.3
Manufacturer: GSM Model 23025 Serial Number 10845
Made in week 9 of 2015
Digital display
Maximum image size: 80 cm x 34 cm
Gamma: 2.20
DPMS levels: Standby Suspend Off
RGB color display
First detailed timing is preferred timing
Color Characteristics
  Red: 0.6513, 0.3320
  Green: 0.3066, 0.6308
  Blue: 0.1503, 0.0595
  White: 0.3134, 0.3291
Established Timings I & II
    720x400 70.082 Hz 9:5 31.467 kHz 28.320 MHz (IBM)
    640x480 59.940 Hz 4:3 31.469 kHz 25.175 MHz (DMT)
    640x480 75.000 Hz 4:3 37.500 kHz 31.500 MHz (DMT)
    800x600 60.317 Hz 4:3 37.879 kHz 40.000 MHz (DMT)
    800x600 75.000 Hz 4:3 46.875 kHz 49.500 MHz (DMT)
   1024x768 60.004 Hz 4:3 48.363 kHz 65.000 MHz (DMT)
   1024x768 75.029 Hz 4:3 60.023 kHz 78.750 MHz (DMT)
   1280x1024 75.025 Hz 5:4 79.976 kHz 135.000 MHz (DMT)
   1152x870 75.062 Hz 192:145 68.681 kHz 100.000 MHz (Apple)
Standard Timings
   1152x864 75.000 Hz 4:3 67.500 kHz 108.000 MHz (DMT)
   1280x1024 60.020 Hz 5:4 63.981 kHz 108.000 MHz (DMT)
   1280x720 60.000 Hz 16:9 45.000 kHz 74.250 MHz (DMT)
   1600x900 60.000 Hz 16:9 60.000 kHz 108.000 MHz (DMT, RB)
   1680x1050 59.954 Hz 16:10 65.290 kHz 146.250 MHz (DMT)
Detailed mode: Clock 185.580 MHz, 798 mm x 334 mm
               2560 2624 2688 2784 ( 64 64 96)
               1080 1083 1093 1111 ( 3 10 18)
               -hsync -vsync
               VertFreq: 60.000 Hz, HorFreq: 66.659 kHz
Detailed mode: Clock 148.500 MHz, 798 mm x 334 mm
               1920 2008 2052 2200 ( 88 44 148)
               1080 1084 1089 1125 ( 4 5 36)
               +hsync +vsync
               VertFreq: 60.000 Hz, HorFreq: 67.500 kHz
Display Product Name: LG ULTRAWIDE
Display Range Limits
  Monitor ranges (GTF): 56-75 Hz V, 30-90 kHz H, max dotclock 240 MHz
Has 1 extension block
Checksum: 0x7b

----------------

CTA-861 Extension Block Revision 3
Underscans PC formats by default
Basic audio support
Supports YCbCr 4:4:4
Supports YCbCr 4:2:2
1 native detailed modes
25 bytes of CTA data blocks
  Video Data Block
     1920x1080 60.000 Hz 16:9 67.500 kHz 148.500 MHz (VIC 16, native)
     1280x720 60.000 Hz 16:9 45.000 kHz 74.250 MHz (VIC 4)
      720x480 59.940 Hz 16:9 31.469 kHz 27.000 MHz (VIC 3)
     1920x1080 30.000 Hz 16:9 33.750 kHz 74.250 MHz (VIC 34)
     1920x1080i 50.000 Hz 16:9 28.125 kHz 74.250 MHz (VIC 20)
      720x576 50.000 Hz 16:9 31.250 kHz 27.000 MHz (VIC 18)
     1920x1080i 60.000 Hz 16:9 33.750 kHz 74.250 MHz (VIC 5)
     1920x1080 50.000 Hz 16:9 56.250 kHz 148.500 MHz (VIC 31)
      640x480 59.940 Hz 4:3 31.469 kHz 25.175 MHz (VIC 1)
     1280x720 50.000 Hz 16:9 37.500 kHz 74.250 MHz (VIC 19)
  Audio Data Block
    Linear PCM, max channels 2
      Supported sample rates (kHz): 48 44.1 32
      Supported sample sizes (bits): 24 20 16
  Speaker Allocation Data Block
    Speaker m...