Since I do my development with lockdep on, this will help make sure I
don't introduce bugs here.
Signed-off-by: NEric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20170725182718.31468-3-eric@anholt.netReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>