[Intel-gfx] ILK output training hangs

[Jesse Barnes]

On Fri, 30 Jul 2010 16:12:34 +1000
Dave Airlie <airlied at gmail.com> wrote:

> 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.

We have a few bugs open that sound similar, for some reason VGA seems
to commonly fail on Ironlake.  I'll try to reproduce on a couple of
systems I have here...

-- 
Jesse Barnes, Intel Open Source Technology Center