drm/i915: hook up LVDS DPMS property

The LVDS output supports DPMS calls, but we never hooked up the property code,
so set property calls didn't actually do anything.  Implement a set_property
callback for the LVDS output so that the right thing happens.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/gpu/drm/i915/intel_lvds.c

@@ -340,6 +340,18 @@ static void intel_lvds_destroy(struct drm_connector *connector)
 	kfree(connector);
 }
 
+static int intel_lvds_set_property(struct drm_connector *connector,
+				   struct drm_property *property,
+				   uint64_t value)
+{
+	struct drm_device *dev = connector->dev;
+
+	if (property == dev->mode_config.dpms_property && connector->encoder)
+		intel_lvds_dpms(connector->encoder, (uint32_t)(value & 0xf));
+
+	return 0;
+}
+
 static const struct drm_encoder_helper_funcs intel_lvds_helper_funcs = {
 	.dpms = intel_lvds_dpms,
 	.mode_fixup = intel_lvds_mode_fixup,
@@ -359,6 +371,7 @@ static const struct drm_connector_funcs intel_lvds_connector_funcs = {
 	.restore = intel_lvds_restore,
 	.detect = intel_lvds_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
+	.set_property = intel_lvds_set_property,
 	.destroy = intel_lvds_destroy,
 };