lib/drmtest: add gpu quiescent helper

Some tests are higly timing dependent and others carelessly leave
active buffers behind. So add a helper to quiescent the gpu and call
it unconditionally when opening an fd in a vain attempt to make all
this race-condition hitting more scientifically sound.

Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2 files changed