W9RAN wrote: ↑
Sat Sep 19, 2020 4:39 pm
New headless Pi 4, dmesg is filled with this message at the rate of one per second:
broken atomic modeset userspace detected, disabling atomic
How do I make it stop?
I have experienced this as well. For my situation, the problem is with VNC.
I am running headless, and have VNC enabled so that I can connect remotely from another system. VNC on the pi expects to interface with either a virtual or a real screen, and seems to be upset if a realistic one does not exist, which will happen if a screen resolution is not set. You will find that if you connect to it with a VNC session, you will get a tiny screen that says "Cannot currently show the desktop" and you can't do anything with the desktop. The /var/log/messages and /var/log/syslog will show plenty of the "broken atomic modeset userspace" messages as you describe.
==> Solution: If you are running it headless and try to connect remotely with VNC, you need to establish a screen resolution. You can do this from the command line interface with raspi-config.
Select "Advanced options" -> "Resolution" and select a value (any). Exit and reboot. You should now be able to connect via VNC, but the resolution may or may not be the value that you selected with raspi-config. Set it to what you want and reboot again. Setting it the second time should preserve what you want, and the messages in /var/log/messages and /var/log/syslog will go away.
[This is also described correctly with the "raspi-config" option at https://www.tomshardware.com/how-to/fix ... spberry-pi