Revert "drm: Unify handling of blob and object properties"

This reverts commit 77953bd1.

This causes a kernel panic when trying to assign a blob to a property,
and has obviously never been tested.

Fixes: 77953bd1 ("drm: Unify handling of blob and object properties")
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Tested-by: Liu Ying <gnuiyl@gmail.com>
Acked-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/8c0d3482-1bb5-6a15-b105-6bda2b31b5dc@linux.intel.com

drivers/gpu/drm/drm_property.c

@@ -870,8 +870,20 @@ bool drm_property_change_valid_get(struct drm_property *property,
 		for (i = 0; i < property->num_values; i++)
 			valid_mask |= (1ULL << property->values[i]);
 		return !(value & ~valid_mask);
-	} else if (drm_property_type_is(property, DRM_MODE_PROP_BLOB) ||
-		   drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {
+	} else if (drm_property_type_is(property, DRM_MODE_PROP_BLOB)) {
+		struct drm_property_blob *blob;
+
+		if (value == 0)
+			return true;
+
+		blob = drm_property_lookup_blob(property->dev, value);
+		if (blob) {
+			*ref = &blob->base;
+			return true;
+		} else {
+			return false;
+		}
+	} else if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {
 		/* a zero value for an object property translates to null: */
 		if (value == 0)
 			return true;
@@ -893,7 +905,8 @@ void drm_property_change_valid_put(struct drm_property *property,
 	if (!ref)
 		return;
 
-	if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT) ||
-	    drm_property_type_is(property, DRM_MODE_PROP_BLOB))
+	if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {
 		drm_mode_object_unreference(ref);
+	} else if (drm_property_type_is(property, DRM_MODE_PROP_BLOB))
+		drm_property_unreference_blob(obj_to_blob(ref));
 }