Comment # 1 on bug 936308 from Takashi Iwai

Could you try kernels in OBS home:tiwai:kernel:3.17, 3.18 and 3.19 to figure
out where the regression was introduced?

Also, does the DVI output gets back when you run xrandr manually again, e.g.
like
  xrandr --output DVI-1 --off
  xrandr --output DVI-1 --auto
?  (the output name must match with the actual one)

Last but not least, boot 4.1 kernel with drm.debug=0x0e option, do
suspend/resume and give the full dmesg output to bugzilla.  This will contain
verbose logs of i915 driver.