Comment # 1 on bug 966908 from Takashi Iwai

Please give the detail of your hardware.  At least, give hwinfo --gfxcard
output, as well as the kernel messages.  The problem appears pretty much
specific to the driver.

Also, make sure that this doesn't happen with 4.3.x kernel.  If you don't have
it any longer on your system, 4.3.x kernel packages are found in OBS
home:tiwai:kernel:4.3 repo.

Once when confirmed that it's a 4.4 kernel regression, boot with drm.debug=0x0e
boot option, record the kernel messages around the problem happens and attach
to Bugzilla.