https://bugs.freedesktop.org/show_bug.cgi?id=86413
--- Comment #4 from Andreas Grois dragon.arises@gmail.com --- Created attachment 109645 --> https://bugs.freedesktop.org/attachment.cgi?id=109645&action=edit dmesg of the bad configuration
Again, probably not very helpful, but here's the dmesg output of a bad configuration.