[PATCH] drm: Don't race connector registration

[Dave Hansen]

On 01/30/2017 01:12 AM, Daniel Vetter wrote:
> On Thu, Jan 26, 2017 at 12:34:29PM -0800, Dave Hansen wrote:
...
>> And, yeah, I think it just gets the connected status wrong.  The
>> connector is still there.
> 
> Hm, I thought I replied here but I didn't:
> - Is this just after boot (and then the connector is stuck forever), or
>   starts to happen after suspend/resume, or some other system change like
>   that? Or do they just crop up eventually?

The most consistent thing I do to screw it up is switch systems on my
DVI KVM switch.  When I switch back to the system in question, it
doesn't seem to notice the condition.  The connectors eventually show up
with random combinations of switching to the console (ctrl-alt-f1) and
back, running xrandr, or running gnome-control-panel and opening the
Displays applet.

I haven't been able to discern any pattern to it.  Sometimes just
running xrandr fixes it.  Sometimes just opening the control panel.
Others, I have to do it several times.

I don't think it shows up if I just leave it for a while.

> - Does this only happen once the connector is destroyed? Please trace
>   intel_dp_destroy_mst_connector with something like:

I'll see if I can gather that.