edp backtrace spam on MacBookAir4,1

[Linus Torvalds]

On Wed, May 30, 2012 at 9:00 AM, Daniel Vetter <daniel at ffwll.ch> wrote:
>
> Hm, that's pretty strange that you can't reproduce this any more. We check
> this has_edp stuff once at boot and then never touch it again.

Actually, I think I just figured out how to reproduce it: try to
suspend with the micro-DP <-> VGA dongle, and attached to the screen.
The suspend will fail, and the VGA screen does *not* come on again,
and the messages happen.

But I didn't have drm.debug on this time - but I suspect that Chris
will now be able to reproduce it easily with that information.

This time it also seems to be preceded by this message:

 [drm:intel_cpt_verify_modeset]  *ERROR* mode set failed: pipe 0 stuck

but that didn't happen last time so it may or may not be related.

                     Linus