[PATCH 4/4] mac80211: notify driver of rate control updates

[Johannes Berg <johannes@sipsolutions.net>]

From: Johannes Berg <johannes.berg@intel.com>

Devices that have internal rate control need to be
notified when the bandwidth or SMPS state changes
just like external rate control algorithms get a
notification now.

Add this notification and clarify the change bits
while at it, the HT_CHANGED bit really meant only
bandwidth changed.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 Documentation/DocBook/80211.tmpl    |    2 -
 drivers/net/wireless/ath/ath9k/rc.c |    2 -
 include/net/mac80211.h              |   37 +++++++++++++++++++++++-------------
 net/mac80211/driver-ops.h           |   17 ++++++++++++++++
 net/mac80211/driver-trace.h         |   28 +++++++++++++++++++++++++++
 net/mac80211/mlme.c                 |    2 -
 net/mac80211/rate.h                 |    2 +
 7 files changed, 74 insertions(+), 16 deletions(-)

--- a/Documentation/DocBook/80211.tmpl	2012-03-16 14:13:10.000000000 +0100
+++ b/Documentation/DocBook/80211.tmpl	2012-03-16 14:25:57.000000000 +0100
@@ -533,7 +533,7 @@ MISSING
 !Finclude/net/mac80211.h ieee80211_start_tx_ba_cb_irqsafe
 !Finclude/net/mac80211.h ieee80211_stop_tx_ba_session
 !Finclude/net/mac80211.h ieee80211_stop_tx_ba_cb_irqsafe
-!Finclude/net/mac80211.h rate_control_changed
+!Finclude/net/mac80211.h ieee80211_rate_control_changed
 !Finclude/net/mac80211.h ieee80211_tx_rate_control
 !Finclude/net/mac80211.h rate_control_send_low
       </chapter>
--- a/include/net/mac80211.h	2012-03-16 14:14:31.000000000 +0100
+++ b/include/net/mac80211.h	2012-03-16 14:36:25.000000000 +0100
@@ -1778,6 +1778,18 @@ enum ieee80211_frame_release_type {
 };
 
 /**
+ * enum ieee80211_rate_control_changed - flags to indicate what changed
+ *
+ * @IEEE80211_RC_BW_CHANGED: The bandwidth that can be used to transmit
+ *	to this station changed.
+ * @IEEE80211_RC_SMPS_CHANGED: The SMPS state of the station changed.
+ */
+enum ieee80211_rate_control_changed {
+	IEEE80211_RC_BW_CHANGED		= BIT(0),
+	IEEE80211_RC_SMPS_CHANGED	= BIT(1),
+};
+
+/**
  * struct ieee80211_ops - callbacks from mac80211 to the driver
  *
  * This structure contains various callbacks that the driver may
@@ -1978,6 +1990,14 @@ enum ieee80211_frame_release_type {
  *	up the list of states.
  *	The callback can sleep.
  *
+ * @sta_rc_update: Notifies the driver of changes to the bitrates that can be
+ *	used to transmit to the station. The changes are advertised with bits
+ *	from &enum ieee80211_rate_control_changed and the values are reflected
+ *	in the station data. This callback should only be used when the driver
+ *	uses hardware rate control (%IEEE80211_HW_HAS_RATE_CONTROL) since
+ *	otherwise the rate control algorithm is notified directly.
+ *	Must be atomic.
+ *
  * @conf_tx: Configure TX queue parameters (EDCF (aifs, cw_min, cw_max),
  *	bursting) for a hardware TX queue.
  *	Returns a negative error code on failure.
@@ -2194,6 +2214,10 @@ struct ieee80211_ops {
 			 struct ieee80211_sta *sta,
 			 enum ieee80211_sta_state old_state,
 			 enum ieee80211_sta_state new_state);
+	void (*sta_rc_update)(struct ieee80211_hw *hw,
+			      struct ieee80211_vif *vif,
+			      struct ieee80211_sta *sta,
+			      u32 changed);
 	int (*conf_tx)(struct ieee80211_hw *hw,
 		       struct ieee80211_vif *vif, u16 queue,
 		       const struct ieee80211_tx_queue_params *params);
@@ -3510,19 +3534,6 @@ void ieee80211_send_bar(struct ieee80211
 /* Rate control API */
 
 /**
- * enum rate_control_changed - flags to indicate which parameter changed
- *
- * @IEEE80211_RC_HT_CHANGED: The HT parameters of the operating channel have
- *	changed, rate control algorithm can update its internal state if needed.
- * @IEEE80211_RC_SMPS_CHANGED: The SMPS state of the station changed, the rate
- *	control algorithm needs to adjust accordingly.
- */
-enum rate_control_changed {
-	IEEE80211_RC_HT_CHANGED		= BIT(0),
-	IEEE80211_RC_SMPS_CHANGED	= BIT(1),
-};
-
-/**
  * struct ieee80211_tx_rate_control - rate control information for/from RC algo
  *
  * @hw: The hardware the algorithm is invoked for.
--- a/drivers/net/wireless/ath/ath9k/rc.c	2012-03-16 14:14:31.000000000 +0100
+++ b/drivers/net/wireless/ath/ath9k/rc.c	2012-03-16 14:28:34.000000000 +0100
@@ -1447,7 +1447,7 @@ static void ath_rate_update(void *priv,
 
 	/* FIXME: Handle AP mode later when we support CWM */
 
-	if (changed & IEEE80211_RC_HT_CHANGED) {
+	if (changed & IEEE80211_RC_BW_CHANGED) {
 		if (sc->sc_ah->opmode != NL80211_IFTYPE_STATION)
 			return;
 
--- a/net/mac80211/mlme.c	2012-03-16 14:23:40.000000000 +0100
+++ b/net/mac80211/mlme.c	2012-03-16 14:28:30.000000000 +0100
@@ -219,7 +219,7 @@ static u32 ieee80211_config_ht_tx(struct
 			sta->sta.ht_cap.cap |= IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 
 		rate_control_rate_update(local, sband, sta,
-					 IEEE80211_RC_HT_CHANGED);
+					 IEEE80211_RC_BW_CHANGED);
 	}
 	mutex_unlock(&local->sta_mtx);
 
--- a/net/mac80211/driver-trace.h	2012-03-15 20:43:13.000000000 +0100
+++ b/net/mac80211/driver-trace.h	2012-03-16 14:37:24.000000000 +0100
@@ -624,6 +624,34 @@ TRACE_EVENT(drv_sta_state,
 	)
 );
 
+TRACE_EVENT(drv_sta_rc_update,
+	TP_PROTO(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata,
+		 struct ieee80211_sta *sta,
+		 u32 changed),
+
+	TP_ARGS(local, sdata, sta, changed),
+
+	TP_STRUCT__entry(
+		LOCAL_ENTRY
+		VIF_ENTRY
+		STA_ENTRY
+		__field(u32, changed)
+	),
+
+	TP_fast_assign(
+		LOCAL_ASSIGN;
+		VIF_ASSIGN;
+		STA_ASSIGN;
+		__entry->changed = changed;
+	),
+
+	TP_printk(
+		LOCAL_PR_FMT  VIF_PR_FMT  STA_PR_FMT " changed: 0x%x",
+		LOCAL_PR_ARG, VIF_PR_ARG, STA_PR_ARG, __entry->changed
+	)
+);
+
 TRACE_EVENT(drv_sta_add,
 	TP_PROTO(struct ieee80211_local *local,
 		 struct ieee80211_sub_if_data *sdata,
--- a/net/mac80211/driver-ops.h	2012-03-15 20:43:13.000000000 +0100
+++ b/net/mac80211/driver-ops.h	2012-03-16 14:35:54.000000000 +0100
@@ -474,6 +474,23 @@ int drv_sta_state(struct ieee80211_local
 	return ret;
 }
 
+static inline void drv_sta_rc_update(struct ieee80211_local *local,
+				     struct ieee80211_sub_if_data *sdata,
+				     struct ieee80211_sta *sta, u32 changed)
+{
+	might_sleep();
+
+	sdata = get_bss_sdata(sdata);
+	check_sdata_in_driver(sdata);
+
+	trace_drv_sta_rc_update(local, sdata, sta, changed);
+	if (local->ops->sta_rc_update)
+		local->ops->sta_rc_update(&local->hw, &sdata->vif,
+					  sta, changed);
+
+	trace_drv_return_void(local);
+}
+
 static inline int drv_conf_tx(struct ieee80211_local *local,
 			      struct ieee80211_sub_if_data *sdata, u16 queue,
 			      const struct ieee80211_tx_queue_params *params)
--- a/net/mac80211/rate.h	2012-03-16 14:14:31.000000000 +0100
+++ b/net/mac80211/rate.h	2012-03-16 14:38:20.000000000 +0100
@@ -17,6 +17,7 @@
 #include <net/mac80211.h>
 #include "ieee80211_i.h"
 #include "sta_info.h"
+#include "driver-ops.h"
 
 struct rate_control_ref {
 	struct ieee80211_local *local;
@@ -72,6 +73,7 @@ static inline void rate_control_rate_upd
 	if (ref && ref->ops->rate_update)
 		ref->ops->rate_update(ref->priv, sband, ista,
 				      priv_sta, changed);
+	drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
 }
 
 static inline void *rate_control_alloc_sta(struct rate_control_ref *ref,