No display after resume in r196086

[Damian Gerow]

Attilio Rao wrote:
: why don't you directly try the revision immediately before newbus
: locking (so immediately prior to r196037) and try to verify it still
: works.

Culprit confirmed: I can resume with r196036, but not r196037.

: I'm aware of at least one possible deadlock source but it should not
: happen while suspend/resume. However, I'm preparing an errata patch
: for newbus locking.
: If you verify newbus locking is the real culprit and that my further
: patch doesn't fix your problem we can try to hammer it down further.

Let me know what else you might need.