[Intel-gfx] ILK output training hangs

[Dave Airlie]

Current testing machine is an HP 2740p with Ironlake graphics.

Test sequence:

boot with no VGA plugged in.
get up to gnome logged in,
plug in VGA,

one of three things occur,
a) it works,
b) it hangs in FDI link training (endless while loop wtf?)
c) it gets past the hang but nothing on the monitor.

If (a) happens and I suspend/resume the monitor invariably gets wrong
timings, in this case
it appears we set the fbcon mode, but when we go to change to the X
mode, the PCH DPLL won't accept the new values.
It won't even dpms off.

Just posting in case anyone else can reproduce or has any insight, I'm
not running a fully upstream kernel (testing on RHEL6 with lots of
backports).
and we don't  seem to have a tree with all the patches on the list collected.

Dave.