Comment # 23 on bug 69723 from Alexandre Demers

(In reply to comment #22)
> (In reply to comment #19)
> > Official kernel 3.12 still failing with latest mesa and drm. It always ends
> > up with a white screen when it freezes and it is impossible to connect
> > remotely by SSH.
> > 
> > Would it be possible to add some debug/trace option to find where was the
> > last recorded call or to print some key values/settings when they are
> > changed/set? Maybe that could help narrow down where it hangs.
> 
> The problem is the driver is not really involved except for the initial
> programming of the states.  The GPU does the reclocking internally once it's
> enabled.  Best bet would be to adjust the values programmed into the state
> that's loaded into the SMC to see if you can narrow down what aspects are
> problematic.

Well, maybe the first thing would be to identify when or what sequence leads to
the hang. That's why I was suggesting to trace it. But if I understand you
correctly, you are saying the GPU is programmed once and then we just move from
state to another, right?

I'm not sure, but I think I've read somewhere it was possible to set a power
state manually, to force dpm to a given state in other words. Am I right?