Xorg problem with recent kernels? (Resolved)

[baryon]

With the most recent minimal Debian image, Armbian_26.2.1_Bananapim2s_trixie_current_6.18.15_minimal.img on my A311D, I hit a problem with Xorg. Instead of starting up into dwm via lightdm's autologin, all I got was the blank blinking cursor screen. Working through it with an LLM, the resolution worked out to be adding a stanza to Xorg.conf.

 

Section "ServerFlags"
    Option "AutoAddGPU" "false"
EndSection

 

Is this the correct solution? Is this known or understood? I know nothing about any of this. I presume it's related to how the devices look to Xorg via the kernel, but I have no understanding beyond that level, if that's even correct.