udev_device_get_parent_with_subsystem_devtype(): Clarify documentation

devtype can be NULL, in which case it is ignored for matching.

diff --git a/libudev/libudev-device.c b/libudev/libudev-device.c
index 5d1ad9f223acb307adc65c9dec6f0af681807a1d..4717b582b384b09bf6691426991dd4aea661761b 100644 (file)
--- a/libudev/libudev-device.c
+++ b/libudev/libudev-device.c
@@ -577,6 +577,9 @@ struct udev_device *udev_device_get_parent(struct udev_device *udev_device)
  * value, and fill in information from the sys device and the udev
  * database entry.
  *
+ * If devtype is NULL, only subsystem is checked, and any devtype will
+ * match.
+ *
  * The returned the device is not referenced. It is attached to the
  * child device, and will be cleaned up when the child device
  * is cleaned up.