Somehow I've overlooked this when simplifying the irq reinit
scheme on gen4.5+ in
commit 
78ad455fd229c6f6cc2f390ccbe0d8f1a62d55a9
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu May 22 22:18:21 2014 +0200
    drm/i915: Improve irq handling after gpu resets
Since display interrups in general survive a gpu reset on those
platforms there's also no need to reinit the hotplug settings.
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
                 */
                if (INTEL_INFO(dev)->gen > 5)
                        intel_reset_gt_powersave(dev);
-
-               intel_hpd_init(dev);
        } else {
                mutex_unlock(&dev->struct_mutex);
        }