I was conflating two at least partially independent issues in this post:
- screen tearing
- SPDIF audio getting disabled (SPDIF Audio output disabled when switching from one to two displays)
The audio problem is solved in the linked post.
The easiest solution to screen tearing is 20-intel.conf
file, after all. I'm using this one:
## /etc/X11/xorg.conf.d
Section "Device"
Identifier "Intel Graphics"
Driver "Intel"
Option "AccelMethod" "sna"
Option "TearFree" "True"
Option "Tiling" "True"
Option "SwapbuffersWait" "True"
#Option "AccelMethod" "uxa"
EndSection