https://bugs.freedesktop.org/show_bug.cgi?id=69340
--- Comment #12 from José Suárez j.suarez.agapito@gmail.com --- Well, I am not that advanced as to compile my own mesa et ali from git, but I have rebuild my mesa .deb packages with those missing parenthesis manually applied to the source code and I can confirm that those gpu hangs / crashes are gone. So the problem is solved in current master.
Thanks for the cooperative investigation! ;)
Regards