https://bugzilla.kernel.org/show_bug.cgi?id=51381
--- Comment #2 from a@anrd.net 2012-12-07 16:18:48 --- Since this is a regression (everything worked like a charm in 3.6.6) i would guess the logic is in place and that this is just a side effect of some other fix. But that's only a guess as I'm not a kernel developer.