Index: uspace/lib/c/generic/async.c
===================================================================
--- uspace/lib/c/generic/async.c	(revision a1026daf544b91d3c8e6d81817113aece3c7440e)
+++ uspace/lib/c/generic/async.c	(revision dfeb4e22456c87386fa60f7ec044d07663801acb)
@@ -844,5 +844,5 @@
  * @param port_id ID of the newly created port.
  *
- * @return Zero on success or a negative error code.
+ * @return Zero on success or an error code.
  *
  */
@@ -1053,5 +1053,5 @@
  * @param[out] handle  IRQ capability handle on success.
  *
- * @return Negative error code.
+ * @return An error code.
  *
  */
@@ -1089,5 +1089,5 @@
  * @param cap     IRQ capability handle. 
  *
- * @return Zero on success or a negative error code.
+ * @return Zero on success or an error code.
  *
  */
@@ -1106,5 +1106,5 @@
  * @param data    Notification handler client data.
  *
- * @return Zero on success or a negative error code.
+ * @return Zero on success or an error code.
  *
  */
@@ -1139,5 +1139,5 @@
  * @param data    Notification handler client data.
  *
- * @return Zero on success or a negative error code.
+ * @return Zero on success or an error code.
  *
  */
@@ -1915,5 +1915,5 @@
  * @param r5      If non-NULL, storage for the 5th reply argument.
  *
- * @return Return code of the reply or a negative error code.
+ * @return Return code of the reply or an error code.
  *
  */
@@ -1967,5 +1967,5 @@
  * @param r5      If non-NULL, storage for the 5th reply argument.
  *
- * @return Return code of the reply or a negative error code.
+ * @return Return code of the reply or an error code.
  *
  */
@@ -2108,5 +2108,5 @@
  * @param arg3            User defined argument.
  *
- * @return Zero on success or a negative error code.
+ * @return Zero on success or an error code.
  *
  */
@@ -2433,5 +2433,5 @@
  * @param sess Session to hung up.
  *
- * @return Zero on success or a negative error code.
+ * @return Zero on success or an error code.
  *
  */
@@ -2613,5 +2613,5 @@
  *              base address. Cannot be NULL.
  *
- * @return Zero on success or a negative error code from errno.h.
+ * @return Zero on success or an error code from errno.h.
  *
  */
@@ -2688,5 +2688,5 @@
  * @param flags Flags to be used for sharing. Bits can be only cleared.
  *
- * @return Zero on success or a negative error code from errno.h.
+ * @return Zero on success or an error code from errno.h.
  *
  */
@@ -2774,5 +2774,5 @@
  * @param size Size of the destination buffer.
  *
- * @return Zero on success or a negative error code from errno.h.
+ * @return Zero on success or an error code from errno.h.
  *
  */
@@ -2899,5 +2899,5 @@
  * @param size Size of the source buffer.
  *
- * @return Zero on success or a negative error code from errno.h.
+ * @return Zero on success or an error code from errno.h.
  *
  */