mac80211: extend set_coverage_class signature

Extend mac80211 set_coverage_class API in order to enable ACK timeout
estimation algorithm (dynack) passing coverage class equals to -1
to lower drivers. Synchronize set_coverage_class routine signature with
mac80211 function pointer for p54, ath9k, ath9k_htc and ath5k drivers.
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/ath/ath5k/mac80211-ops.c

@@ -704,7 +704,7 @@ ath5k_get_survey(struct ieee80211_hw *hw, int idx, struct survey_info *survey)
  * reset.
  */
 static void
-ath5k_set_coverage_class(struct ieee80211_hw *hw, u8 coverage_class)
+ath5k_set_coverage_class(struct ieee80211_hw *hw, s16 coverage_class)
 {
 	struct ath5k_hw *ah = hw->priv;
 

drivers/net/wireless/ath/ath9k/htc_drv_main.c

@@ -1722,7 +1722,7 @@ static int ath9k_htc_set_rts_threshold(struct ieee80211_hw *hw, u32 value)
 }
 
 static void ath9k_htc_set_coverage_class(struct ieee80211_hw *hw,
-					 u8 coverage_class)
+					 s16 coverage_class)
 {
 	struct ath9k_htc_priv *priv = hw->priv;
 

drivers/net/wireless/ath/ath9k/main.c

@@ -1959,7 +1959,8 @@ static int ath9k_get_survey(struct ieee80211_hw *hw, int idx,
 	return 0;
 }
 
-static void ath9k_set_coverage_class(struct ieee80211_hw *hw, u8 coverage_class)
+static void ath9k_set_coverage_class(struct ieee80211_hw *hw,
+				     s16 coverage_class)
 {
 	struct ath_softc *sc = hw->priv;
 	struct ath_hw *ah = sc->sc_ah;

drivers/net/wireless/p54/main.c

@@ -696,7 +696,8 @@ static void p54_flush(struct ieee80211_hw *dev, struct ieee80211_vif *vif,
 	WARN(total, "tx flush timeout, unresponsive firmware");
 }
 
-static void p54_set_coverage_class(struct ieee80211_hw *dev, u8 coverage_class)
+static void p54_set_coverage_class(struct ieee80211_hw *dev,
+				   s16 coverage_class)
 {
 	struct p54_common *priv = dev->priv;
 

include/net/mac80211.h

@@ -2673,7 +2673,9 @@ enum ieee80211_roc_type {
  *
  * @set_coverage_class: Set slot time for given coverage class as specified
  *	in IEEE 802.11-2007 section 17.3.8.6 and modify ACK timeout
- *	accordingly. This callback is not required and may sleep.
+ *	accordingly; coverage class equals to -1 to enable ACK timeout
+ *	estimation algorithm (dynack). To disable dynack set valid value for
+ *	coverage class. This callback is not required and may sleep.
  *
  * @testmode_cmd: Implement a cfg80211 test mode command. The passed @vif may
  *	be %NULL. The callback can sleep.
@@ -2957,7 +2959,7 @@ struct ieee80211_ops {
 	int (*get_survey)(struct ieee80211_hw *hw, int idx,
 		struct survey_info *survey);
 	void (*rfkill_poll)(struct ieee80211_hw *hw);
-	void (*set_coverage_class)(struct ieee80211_hw *hw, u8 coverage_class);
+	void (*set_coverage_class)(struct ieee80211_hw *hw, s16 coverage_class);
 #ifdef CONFIG_NL80211_TESTMODE
 	int (*testmode_cmd)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			    void *data, int len);

net/mac80211/cfg.c

@@ -1978,8 +1978,13 @@ static int ieee80211_set_wiphy_params(struct wiphy *wiphy, u32 changed)
 			return err;
 	}
 
-	if (changed & WIPHY_PARAM_COVERAGE_CLASS) {
-		err = drv_set_coverage_class(local, wiphy->coverage_class);
+	if ((changed & WIPHY_PARAM_COVERAGE_CLASS) ||
+	    (changed & WIPHY_PARAM_DYN_ACK)) {
+		s16 coverage_class;
+
+		coverage_class = changed & WIPHY_PARAM_COVERAGE_CLASS ?
+					wiphy->coverage_class : -1;
+		err = drv_set_coverage_class(local, coverage_class);
 
 		if (err)
 			return err;

net/mac80211/driver-ops.h

@@ -450,7 +450,7 @@ static inline int drv_set_rts_threshold(struct ieee80211_local *local,
 }
 
 static inline int drv_set_coverage_class(struct ieee80211_local *local,
-					 u8 value)
+					 s16 value)
 {
 	int ret = 0;
 	might_sleep();

net/mac80211/trace.h

@@ -672,13 +672,13 @@ DEFINE_EVENT(local_u32_evt, drv_set_rts_threshold,
 );
 
 TRACE_EVENT(drv_set_coverage_class,
-	TP_PROTO(struct ieee80211_local *local, u8 value),
+	TP_PROTO(struct ieee80211_local *local, s16 value),
 
 	TP_ARGS(local, value),
 
 	TP_STRUCT__entry(
 		LOCAL_ENTRY
-		__field(u8, value)
+		__field(s16, value)
 	),
 
 	TP_fast_assign(