iwlwifi: configure missed beacon threshold

Add support to configure missed beacon threshold, by default, if receive
"missed beacon" notification from uCode and has more than 5 consecutive
beacon missed, then perform sensitivity calibration; with this change,
allow user to adjust the missed beacon threshold from debugfs in case
more sensitivity calibration required for better performance in noisy
environment

The default value (=5) should be good enough for the normal condition,
but for very noisy environment, more sensitivity calibration could help
improve the throughput, so by setting the missed beacon threshold to
lower number, user might experience better performance result.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 21 insertions, 4 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-commands.h b/drivers/net/wireless/iwlwifi/iwl-commands.h
index cee5fb2187c8..8823d18b9f43 100644
--- a/drivers/net/wireless/iwlwifi/iwl-commands.h
+++ b/drivers/net/wireless/iwlwifi/iwl-commands.h
@@ -3165,13 +3165,30 @@ struct iwl_notif_statistics {
 
 /*
  * MISSED_BEACONS_NOTIFICATION = 0xa2 (notification only, not a command)
+ *
+ * uCode send MISSED_BEACONS_NOTIFICATION to driver when detect beacon missed
+ * in regardless of how many missed beacons, which mean when driver receive the
+ * notification, inside the command, it can find all the beacons information
+ * which include number of total missed beacons, number of consecutive missed
+ * beacons, number of beacons received and number of beacons expected to
+ * receive.
+ *
+ * If uCode detected consecutive_missed_beacons > 5, it will reset the radio
+ * in order to bring the radio/PHY back to working state; which has no relation
+ * to when driver will perform sensitivity calibration.
+ *
+ * Driver should set it own missed_beacon_threshold to decide when to perform
+ * sensitivity calibration based on number of consecutive missed beacons in
+ * order to improve overall performance, especially in noisy environment.
+ *
  */
-/* if ucode missed CONSECUTIVE_MISSED_BCONS_TH beacons in a row,
- * then this notification will be sent. */
-#define CONSECUTIVE_MISSED_BCONS_TH 20
+
+#define IWL_MISSED_BEACON_THRESHOLD_MIN	(1)
+#define IWL_MISSED_BEACON_THRESHOLD_DEF	(5)
+#define IWL_MISSED_BEACON_THRESHOLD_MAX	IWL_MISSED_BEACON_THRESHOLD_DEF
 
 struct iwl_missed_beacon_notif {
-	__le32 consequtive_missed_beacons;
+	__le32 consecutive_missed_beacons;
 	__le32 total_missed_becons;
 	__le32 num_expected_beacons;
 	__le32 num_recvd_beacons;