 Yes just checked out your trace and got the same screenshot... yes sorry you
are right, but seems to me radeonsi was having a more black even than this
seems like onother bug which got fixed on top of this bug (Sylvain from comment
14 may confirm that with radeonsi). It was like this
https://bugs.freedesktop.org/attachment.cgi?id=99363 and now is much better,
but not complitely correct yet.

 Sorry it is just that radeonsi is now in the same state as r600 to actually
have this bug you describe :).