1

I've got an old Intel Haswell NUC using onboard Intel graphics connected to a new LG monitor with a native resolution of 1920x1080 on the HDMI port.

However, on startup (right after Grub hands off to the kernel, before the "Ubuntu" screen shows up with the spinny triskelion thing) the system decides to change the resolution to 3840x2160 at 30 Hz, which the screen resamples down to its native 1920x1080 and then puts up an overlay saying "please switch to my native resolution." The system remains at this resolution while the login screen is up. Once I login, my user settings kick in and I get 1920x1080 at 120 Hz.

Is there any way to "lock out" the 4K resolution and force it down to HD? It'd probably have to be at the kernel (KMS?) level. The various xrandr-based solutions I've found elsewhere don't work.

P.S. the text screens (e.g. Ctrl-Alt-F2) are still at 3840x2160. The text is tiny and hard to read.

Mike DeSimone
  • 111
  • You're talking about the plymouth screen I gather; why not try using another plymouth screen (even removing it). It doesn't require kernel changes ; see https://askubuntu.com/questions/2007/how-do-i-change-the-plymouth-bootscreen (the plymouth screen used by 21.04 is OEM friendly so uses native resolution as reported by hardware to best show the OEM logo etc) – guiverc Aug 05 '21 at 04:01
  • It's not plymouth-specific; like I noted later, it's present on the plain old text mode screen. – Mike DeSimone Aug 05 '21 at 15:03

1 Answers1

0

Change the boot resolution in grub:
sudo vi /etc/default/grub

Find GRUB_GFXMODE:
type :/GRUB_GFXMODE
and change it to:
GRUB_GFXMODE=1920x1080
Use the cursor to navigate after = press d$ to delete everything until end of line,
then press SHIFT+A (caps lock should be off) to insert at the end of the line: 1920x1080

Below is GRUB_GFXPAYLOAD_LINUX should be already with the right value:
GRUB_GFXPAYLOAD_LINUX=keep

at the end save and quit by typing :qw!

Now update grub:
sudo update-grub

https://www.binarytides.com/ubuntu-fix-nvidia-graphics/ Here he uses grub2, you can try that also and in plus you can set the same resolution for splash screen following these steps.

A. Herlas
  • 96
  • 5
  • That had no effect. BTW, neither line was present in /etc/default/grub, so I just added them after the commented GRUB_GFXMODE block. Also, I use nano instead of vi, so I'm guessing :/ is "search". – Mike DeSimone Aug 05 '21 at 15:14
  • The binarytides link just added echo FRAMEBUFFER=y to /etc/initramfs-tools/conf.d/splash and ran update-initramfs -u. That had the effect of changing the text terminals to the right resolution (as well as giving them a weird font), but gdm3 and plymouth are still using 4K resolution. – Mike DeSimone Aug 06 '21 at 02:40