I've managed to hit something very similar with:
xrandr --output LVDS1 --off --output DP1 --preferred
The registers look fine but the external monitor loses sync. Of particular note is that this change causes drm_remove_fb() to decouple the old framebuffer from crtc0.
I've managed to hit something very similar with:
xrandr --output LVDS1 --off --output DP1 --preferred
The registers look fine but the external monitor loses sync. Of particular note is that this change causes drm_remove_fb() to decouple the old framebuffer from crtc0.