https://bugs.freedesktop.org/show_bug.cgi?id=43405
(If you don't want to follow the links: I get nothing but snow and error messages from Google Earth or glxgears after the commit mentioned in the bug report. I bisected it nearly a month ago, but no-one has tested.)
I haven't tested yet, but this commit did not touch the hack that broke stuff on my hardware...and none of the code that changed looks like it should make a difference.