Comment # 27 on bug 1213438 from Takashi Iwai

(In reply to Günter Halt from comment #25)
> "Is it a kernel crash?  Or only about graphics / desktop?"
> 
> Is it no kernel crash!!!

It was a question rather to Andreas.  His problem might be different from
yours.

> The X-server is running and after any time the green-Display  will be black
> and, if the mouse is moved, green again. Sorry this behaviour was new for me.
> 
> Pleas show the attachment  "dmseg-report-after-crash"  , made on ssh-session.

This doesn't look like a result from the test kernel mentioned in comment 18.
Have you tested with it?