Comment # 3 on bug 933858 from Takashi Iwai

Please make sure that it's a regression in kernel.  You should be able to boot
from the previous kernel by selecting the one in GRUB boot menu.  Try to boot
your current system with the previous kernel.  If the problem is actually gone,
then it implies that the problem is in kernel.  If the problem still exists,
it's no kernel issue but a regression in another component.