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Ubuntu 20.04 HDMI display driver problem

Posted: Sat May 02, 2020 11:00 am
by sidney108
Hi,
I have first time installed Ubuntu 20.04 an my new Pi 4B, 4GB and it runs, but the display settings is only showing 1824x974 (9:5) option.
I have been using Ubuntu for more then a decade, but here I am missing the "additional drivers" section in settings. I have almost new Samsung 4k monitor, but there is just one fixed resolution available.
Any idea?
Thanks a lot...
P.S.: I can't install any other desktop - have tried lubuntu and kubuntu, but both have failed few times. It just hangs with an empty screen towards the end and only cursor (underscore) on it. Needs hard reset. Have tried re-create the install medium - always the same. synaptic has fixed some dependences, but no apparent broken packages. sudo dpkg --configure -a also without any effect... :(

Re: Ubuntu 20.04 HDMI display driver problem

Posted: Sat May 02, 2020 12:55 pm
by salmay
same problem, attached a pi4 to a philips 499P9 configurable as a dual 2560x1440. But is doesn't recognize the displays and only shows that resolution of 1824 x 984

Re: Ubuntu 20.04 HDMI display driver problem

Posted: Sat May 02, 2020 6:06 pm
by blendfish
Just installed this on the kids pi 4 and I'm also getting the display issue. I don't think it's just a resolution issue as I've noticed the screen occasionally glitches / goes black / mouse restores background as I move over the screen.

Resolution is wrong as with the OP.

I'm no expert in this but I think it might be something to do with llvmpipe being used as a software gfx driver instead of the proper hardware ones.

I wouldn't consider this usable on the pi at the moment (you also need a wired connection to install as working internet seems to be required to install the WiFi internet drivers. Genius.

Re: Ubuntu 20.04 HDMI display driver problem

Posted: Sat May 02, 2020 6:23 pm
by waveform80
If you haven't already, try adding the following to /boot/firmware/syscfg.txt (or usercfg.txt):

Code: Select all

dtoverlay=vc4-fkms-v3d
That loads the "fake" KMS framebuffer which is considerably better for desktop usage. There's a few more bits in this post in case they're useful.

Dave.

Re: Ubuntu 20.04 HDMI display driver problem

Posted: Mon May 04, 2020 4:28 am
by ichi
Hi,

thank you very much! The hint with the dtoverlay=vc4-fkms-v3d solved my problem! I was searching a lot before I found this and already wanted to give up.
Thank you!

Gyula