Hello all,

I’ve been scratching my head with this for a while now, and some help would be greatly appreciated. My issue is that my monitor’s native resolution (3440x1440) and refresh rates are not recognized by Ubuntu natively, whether I’m using Wayland or Xorg.

The monitor’s EDID file contains a mode with the actual screen’s resolution in DTD (Detailed Timing Descriptors) format, but neither Xorg nor Wayland seem to be able read it for some reason.

I’ve really tried a few things now, neither of which worked, so a few pointers would be greatly appreciated!

What works

Using X11 and manually setting xrandr’s mode to the output of gtf 3440 1440 60. That’s pretty much the only solution I’ve found to use the monitor’s actual resolution so far.

What did not work

  • Modifying the grub settings to set the video output to the same resolution/framerate as what works on X11
  • Using the edid-generator to generate a custom EDID file using those same settings, and telling grub to take it into account. It was quite a pain to make it work by itself, and I have suspicions that it might not work because it was not built to accommodate resolutions not supported by EDID 1.3 (which are limited 16:10, 4:3, 5:4, 16:9).
  • Doing either of the two previous points using the settings from the EDID file (read from edid-decode < /sys/class/drm/card0-DP-3/edid)
  • Unsurprisingly, trying to use xrandr to set the correct output to the Wayland monitor (XWAYLAND0)
  • Some other stuff, probably not worth mentioning

Some other info

  • Ubuntu 22.04
  • Gnome 42.9
  • X.org 1.21.1.4
  • Mesa Intel Graphics (not a gaming rig, but the chip is able to manage a 3440x1440 output)
  • Laptop: Tuxedo InfinityBook Pro Gen7 / monitor: DELL S3422DWG

Edit: the solution

@HeyLow@lemmy.blahaj.zone cracked it, the problem is from the dongle: I had tested the cable but never the dongle, obviously. Thank you all for your support!

    • Hydroel@lemmy.worldOP
      1·
      1 year ago

      I haven’t, but what would they bring to the table? Would they allow specific tweaks like xrandr?

  • penquin@lemmy.kde.social
    2·
    1 year ago

    Damn, this makes me think that it’s an issue with Dell monitors when connected through DP. I have a similar issue with my monitors on kde where my dell monitor goes into a 1024x768 resolution after a suspend. My other monitor is fine, but it is not dell. So, even if I check the resolutions list, it’s not there anymore 3840x2160 I’d have to reboot then it’ll show up. I wonder if an update somewhere messed with Dell monitors.

    • Hydroel@lemmy.worldOP
      1·
      1 year ago

      Might be that Dell devs don’t give a damn about correct specs (which are usually implemented in Linux) and only test on Windows. Mine is connected in HDMI though.

      Does this monitor work well with Windows?

      • penquin@lemmy.kde.social
        2·
        1 year ago

        No idea. I don’t have windows anywhere on my PC, so can’t tell ya. I can tell you that I don’t have that issue on Wayland never fucking mind, I have it on both now. Only on x11. Wayland has a different issue with the monitor that is not this. Lol Damn, seems like doors walls are closing in on me with Linux. I have all AMD, not sure shit is not working. Using HDMI gives me on 30hz which is stupid. Good thing it fixes for me when I reboot

        • ag10n@lemmy.world
          2·
          1 year ago

          HDMI 2.0 has limited support for high-res displays at 21:9. Check that your cables also are up to the task.

          Running both the internal and external display at these high resolutions will be a challenge, only getting 30hz here makes sense.

    • Hydroel@lemmy.worldOP
      2·
      1 year ago

      Added to the main post. I didn’t in the first place as I’m not so sure it’s relevant (outside of the GPU and supported resolution, which I specified)

      Anyway: Tuxedo InfinityBook Pro Gen 7, DELL S3422DWG