+/* For devices that should just be moved a little bit later, just
+ * before the point where some common path prefix changes. Returns the
+ * number of characters that make up that common prefix */
+static size_t devices_delay_later(struct udev *udev, const char *syspath)
+{
+ const char *c;
+
+ /* For sound cards the control device must be enumerated last
+ * to make sure it's the final device node that gets ACLs
+ * applied. Applications rely on this fact and use ACL changes
+ * on the control node as an indicator that the ACL change of
+ * the entire sound card completed. The kernel makes this
+ * guarantee when creating those devices, and hence we should
+ * too when enumerating them. */
+
+ if ((c = strstr(syspath, "/sound/card"))) {
+ c += 11;
+ c += strcspn(c, "/");
+
+ if (strncmp(c, "/controlC", 9) == 0)
+ return c - syspath + 1;
+ }
+
+ return 0;
+}
+