I already know that the nvidia driver creates the framebuffer after the X server is started, so I have to create an udev rule to make a "seat-master" (or is it "master-of-seat")
Tag "master-of-seat": if set this device is enough for a seat to be considered existent. This tag is
usually set for the framebuffer device of graphics cards. A seat hence consists of an arbitrary
number of devices marked with the "seat" tag, but (at least) one of these devices needs to be
tagged with "master-of-seat" before the seat is actually considered to be around.
Can someone give me an example to set this tag in an udev rule?