Comment # 8 on bug 936308 from Takashi Iwai

(In reply to Daniel Zeleny from comment #7)
> (In reply to Takashi Iwai from comment #6)
> > (In reply to Daniel Zeleny from comment #5)
> > > Probably same bug as reported here?
> > > https://bugs.freedesktop.org/show_bug.cgi?id=89589
> > 
> > Yeah, looks so.
> > 
> > Though, the commit mentioned in the bugzilla is in 3.19-rc2, so this commit
> > can't be the culprit.
> 
> I don't know, but wasn't it backporterd to stable 3.18 branch? I have tried
> kernel from yours repository, which is 3.18.6, not 3.18.0.

Good point!  Indeed the commit was there through stable tree.

> Is there other way to check it, other than install kernel 3.18.0?

You can revert the commit manually.  This should be easily applicable even to
the latest version.  Just move the call of intel_dp_mst_resume(dev) in
i915_drm_resume().

if the revert still works with 4.0 or 4.1 kernel, you can give the kernel
messages with drm.debug=0x0e from both working and non-working cases to
compare.