Comment # 5 on bug 991026 from Egbert Eich

(In reply to Oliver Neukum from comment #4)
> (In reply to Egbert Eich from comment #3)
> > Oliver, please report this upstream on freedesktop.org, add the URL to this
> > ticket and close it with UPSTREAM.
> > If you feel like it, you can of course bisect this as well.
> 
> This does not happen on v4.6 or later.

Then I don't understand your bug report. You've reported this against TW where
the latest kernel is v4.6.4.