On Fri, Dec 31, 2021 at 04:29:30PM +0100, Thomas Klausner wrote: > Yes, I do have one of those. But the behaviour looks quite the same, > some minor changes in the Xorg logfile only, mode 3840x2160 not > available for xrandr.
PEBKAC. I had configured the kernel to restrict DRM to 1920x1080: options DRM_MAX_RESOLUTION_HORIZONTAL=1920 # Limit DRM size in horizontal dimension options DRM_MAX_RESOLUTION_VERTICAL=1080 # Limit DRM size in vertical dimension because otherwise my previous graphics card wasn't working. Not too surprisingly, this feature works and limited the resolution. I've removed these two lines, now I get 4k in the framebuffer and in X. Yay! Thomas
