mac80211: extend sta kdoc - explain when they are added

Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/mac80211/sta_info.c

@@ -44,6 +44,15 @@
  * When the insertion fails (sta_info_insert()) returns non-zero), the
  * structure will have been freed by sta_info_insert()!
  *
+ * sta entries are added by mac80211 when you establish a link with a
+ * peer. This means different things for the different type of interfaces
+ * we support. For a regular station this mean we add the AP sta when we
+ * receive an assocation response from the AP. For IBSS this occurs when
+ * we receive a probe response or a beacon from target IBSS network. For
+ * WDS we add the sta for the peer imediately upon device open. When using
+ * AP mode we add stations for each respective station upon request from
+ * userspace through nl80211.
+ *
  * Because there are debugfs entries for each station, and adding those
  * must be able to sleep, it is also possible to "pin" a station entry,
  * that means it can be removed from the hash table but not be freed.