mac80211: add hardware restart function

Some hardware defects may require the hardware to be re-initialised
completely from scratch. Drivers would need much information (for
instance the current MAC address, crypto keys, beaconing information,
etc.) stored duplicated from mac80211 to be able to do this, so let
mac80211 help them.

The new ieee80211_restart_hw() function requires the same code as
resuming, so move that code into a new ieee80211_reconfig() function
in util.c and leave only the suspend code in pm.c.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 2c6f976..a593bed 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1575,6 +1575,20 @@
  */
 void ieee80211_free_hw(struct ieee80211_hw *hw);
 
+/**
+ * ieee80211_restart_hw - restart hardware completely
+ *
+ * Call this function when the hardware was restarted for some reason
+ * (hardware error, ...) and the driver is unable to restore its state
+ * by itself. mac80211 assumes that at this point the driver/hardware
+ * is completely uninitialised and stopped, it starts the process by
+ * calling the ->start() operation. The driver will need to reset all
+ * internal state that it has prior to calling this function.
+ *
+ * @hw: the hardware to restart
+ */
+void ieee80211_restart_hw(struct ieee80211_hw *hw);
+
 /* trick to avoid symbol clashes with the ieee80211 subsystem */
 void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
 		    struct ieee80211_rx_status *status);