drm/i915: take a power domain ref only when needed during HDMI detect

Suggested by Ville.
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447959301-1263-1-git-send-email-imre.deak@intel.com

drivers/gpu/drm/i915/intel_hdmi.c

@@ -1351,14 +1351,15 @@ intel_hdmi_set_edid(struct drm_connector *connector, bool force)
 	struct edid *edid = NULL;
 	bool connected = false;
 
-	intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
+	if (force) {
+		intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
 
-	if (force)
 		edid = drm_get_edid(connector,
 				    intel_gmbus_get_adapter(dev_priv,
 				    intel_hdmi->ddc_bus));
 
-	intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS);
+		intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS);
+	}
 
 	to_intel_connector(connector)->detect_edid = edid;
 	if (edid && edid->input & DRM_EDID_INPUT_DIGITAL) {