mac80211: support hw scan while idle

Currently, mac80211 goes to idle-off before starting a scan.
However, some devices that implement hw scan might not
need going idle-off in order to perform a hw scan, and
thus saving some energy and simplifying their state machine.

(Note that this is also the case for sched scan - it
currently doesn't make mac80211 go idle-off)

Add a new flag to indicate support for hw scan while idle.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 922313f..cbff4f9 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1164,6 +1164,10 @@
  * @IEEE80211_HW_TX_AMPDU_SETUP_IN_HW: The device handles TX A-MPDU session
  *	setup strictly in HW. mac80211 should not attempt to do this in
  *	software.
+ *
+ * @IEEE80211_HW_SCAN_WHILE_IDLE: The device can do hw scan while
+ *	being idle (i.e. mac80211 doesn't have to go idle-off during the
+ *	the scan).
  */
 enum ieee80211_hw_flags {
 	IEEE80211_HW_HAS_RATE_CONTROL			= 1<<0,
@@ -1190,6 +1194,7 @@
 	IEEE80211_HW_SUPPORTS_PER_STA_GTK		= 1<<21,
 	IEEE80211_HW_AP_LINK_PS				= 1<<22,
 	IEEE80211_HW_TX_AMPDU_SETUP_IN_HW		= 1<<23,
+	IEEE80211_HW_SCAN_WHILE_IDLE			= 1<<24,
 };
 
 /**