mac80211: sync driver before TX

In P2P client mode, the GO (AP) to connect to might
have periods of time where it is not available due
to powersave. To allow the driver to sync with it
and send frames to the GO only when it is available
add a new callback tx_sync (and the corresponding
finish_tx_sync). These callbacks can sleep unlike
the actual TX.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

5 files changed, 122 insertions, 3 deletions

diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index b2d6bba..1425380 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -130,6 +130,37 @@ static inline void drv_bss_info_changed(struct ieee80211_local *local,
 	trace_drv_return_void(local);
 }
 
+static inline int drv_tx_sync(struct ieee80211_local *local,
+			      struct ieee80211_sub_if_data *sdata,
+			      const u8 *bssid,
+			      enum ieee80211_tx_sync_type type)
+{
+	int ret = 0;
+
+	might_sleep();
+
+	trace_drv_tx_sync(local, sdata, bssid, type);
+	if (local->ops->tx_sync)
+		ret = local->ops->tx_sync(&local->hw, &sdata->vif,
+					  bssid, type);
+	trace_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline void drv_finish_tx_sync(struct ieee80211_local *local,
+				      struct ieee80211_sub_if_data *sdata,
+				      const u8 *bssid,
+				      enum ieee80211_tx_sync_type type)
+{
+	might_sleep();
+
+	trace_drv_finish_tx_sync(local, sdata, bssid, type);
+	if (local->ops->finish_tx_sync)
+		local->ops->finish_tx_sync(&local->hw, &sdata->vif,
+					   bssid, type);
+	trace_drv_return_void(local);
+}
+
 static inline u64 drv_prepare_multicast(struct ieee80211_local *local,
 					struct netdev_hw_addr_list *mc_list)
 {
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index 4470f6e8..f47b00dc7 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -319,6 +319,49 @@ TRACE_EVENT(drv_bss_info_changed,
 	)
 );
 
+DECLARE_EVENT_CLASS(tx_sync_evt,
+	TP_PROTO(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata,
+		 const u8 *bssid,
+		 enum ieee80211_tx_sync_type type),
+	TP_ARGS(local, sdata, bssid, type),
+
+	TP_STRUCT__entry(
+		LOCAL_ENTRY
+		VIF_ENTRY
+		__array(char, bssid, ETH_ALEN)
+		__field(u32, sync_type)
+	),
+
+	TP_fast_assign(
+		LOCAL_ASSIGN;
+		VIF_ASSIGN;
+		memcpy(__entry->bssid, bssid, ETH_ALEN);
+		__entry->sync_type = type;
+	),
+
+	TP_printk(
+		LOCAL_PR_FMT  VIF_PR_FMT " bssid:%pM type:%d",
+		LOCAL_PR_ARG, VIF_PR_ARG, __entry->bssid, __entry->sync_type
+	)
+);
+
+DEFINE_EVENT(tx_sync_evt, drv_tx_sync,
+	TP_PROTO(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata,
+		 const u8 *bssid,
+		 enum ieee80211_tx_sync_type type),
+	TP_ARGS(local, sdata, bssid, type)
+);
+
+DEFINE_EVENT(tx_sync_evt, drv_finish_tx_sync,
+	TP_PROTO(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata,
+		 const u8 *bssid,
+		 enum ieee80211_tx_sync_type type),
+	TP_ARGS(local, sdata, bssid, type)
+);
+
 TRACE_EVENT(drv_prepare_multicast,
 	TP_PROTO(struct ieee80211_local *local, int mc_count),
 
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index eb9d482..400c09b 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -323,6 +323,7 @@ struct ieee80211_work {
 			u8 key[WLAN_KEY_LEN_WEP104];
 			u8 key_len, key_idx;
 			bool privacy;
+			bool synced;
 		} probe_auth;
 		struct {
 			struct cfg80211_bss *bss;
@@ -336,6 +337,7 @@ struct ieee80211_work {
 			u8 ssid_len;
 			u8 supp_rates_len;
 			bool wmm_used, use_11n, uapsd_used;
+			bool synced;
 		} assoc;
 		struct {
 			u32 duration;
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index fee706d..d6470c7 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2335,14 +2335,16 @@ static enum work_done_result
 ieee80211_probe_auth_done(struct ieee80211_work *wk,
 			  struct sk_buff *skb)
 {
+	struct ieee80211_local *local = wk->sdata->local;
+
 	if (!skb) {
 		cfg80211_send_auth_timeout(wk->sdata->dev, wk->filter_ta);
-		return WORK_DONE_DESTROY;
+		goto destroy;
 	}
 
 	if (wk->type == IEEE80211_WORK_AUTH) {
 		cfg80211_send_rx_auth(wk->sdata->dev, skb->data, skb->len);
-		return WORK_DONE_DESTROY;
+		goto destroy;
 	}
 
 	mutex_lock(&wk->sdata->u.mgd.mtx);
@@ -2352,6 +2354,12 @@ ieee80211_probe_auth_done(struct ieee80211_work *wk,
 	wk->type = IEEE80211_WORK_AUTH;
 	wk->probe_auth.tries = 0;
 	return WORK_DONE_REQUEUE;
+ destroy:
+	if (wk->probe_auth.synced)
+		drv_finish_tx_sync(local, wk->sdata, wk->filter_ta,
+				   IEEE80211_TX_SYNC_AUTH);
+
+	return WORK_DONE_DESTROY;
 }
 
 int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata,
@@ -2424,6 +2432,7 @@ int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata,
 static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
 						  struct sk_buff *skb)
 {
+	struct ieee80211_local *local = wk->sdata->local;
 	struct ieee80211_mgmt *mgmt;
 	struct ieee80211_rx_status *rx_status;
 	struct ieee802_11_elems elems;
@@ -2431,7 +2440,7 @@ static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
 
 	if (!skb) {
 		cfg80211_send_assoc_timeout(wk->sdata->dev, wk->filter_ta);
-		return WORK_DONE_DESTROY;
+		goto destroy;
 	}
 
 	if (wk->type == IEEE80211_WORK_ASSOC_BEACON_WAIT) {
@@ -2451,6 +2460,10 @@ static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
 	status = le16_to_cpu(mgmt->u.assoc_resp.status_code);
 
 	if (status == WLAN_STATUS_SUCCESS) {
+		if (wk->assoc.synced)
+			drv_finish_tx_sync(local, wk->sdata, wk->filter_ta,
+					   IEEE80211_TX_SYNC_ASSOC);
+
 		mutex_lock(&wk->sdata->u.mgd.mtx);
 		if (!ieee80211_assoc_success(wk, mgmt, skb->len)) {
 			mutex_unlock(&wk->sdata->u.mgd.mtx);
@@ -2464,6 +2477,11 @@ static enum work_done_result ieee80211_assoc_done(struct ieee80211_work *wk,
 	}
 
 	cfg80211_send_rx_assoc(wk->sdata->dev, skb->data, skb->len);
+ destroy:
+	if (wk->assoc.synced)
+		drv_finish_tx_sync(local, wk->sdata, wk->filter_ta,
+				   IEEE80211_TX_SYNC_ASSOC);
+
 	return WORK_DONE_DESTROY;
 }
 
diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index f0c74a1..380b9a7 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -25,6 +25,7 @@
 
 #include "ieee80211_i.h"
 #include "rate.h"
+#include "driver-ops.h"
 
 #define IEEE80211_AUTH_TIMEOUT (HZ / 5)
 #define IEEE80211_AUTH_MAX_TRIES 3
@@ -427,6 +428,14 @@ ieee80211_direct_probe(struct ieee80211_work *wk)
 	struct ieee80211_sub_if_data *sdata = wk->sdata;
 	struct ieee80211_local *local = sdata->local;
 
+	if (!wk->probe_auth.synced) {
+		int ret = drv_tx_sync(local, sdata, wk->filter_ta,
+				      IEEE80211_TX_SYNC_AUTH);
+		if (ret)
+			return WORK_ACT_TIMEOUT;
+	}
+	wk->probe_auth.synced = true;
+
 	wk->probe_auth.tries++;
 	if (wk->probe_auth.tries > IEEE80211_AUTH_MAX_TRIES) {
 		printk(KERN_DEBUG "%s: direct probe to %pM timed out\n",
@@ -466,6 +475,14 @@ ieee80211_authenticate(struct ieee80211_work *wk)
 	struct ieee80211_sub_if_data *sdata = wk->sdata;
 	struct ieee80211_local *local = sdata->local;
 
+	if (!wk->probe_auth.synced) {
+		int ret = drv_tx_sync(local, sdata, wk->filter_ta,
+				      IEEE80211_TX_SYNC_AUTH);
+		if (ret)
+			return WORK_ACT_TIMEOUT;
+	}
+	wk->probe_auth.synced = true;
+
 	wk->probe_auth.tries++;
 	if (wk->probe_auth.tries > IEEE80211_AUTH_MAX_TRIES) {
 		printk(KERN_DEBUG "%s: authentication with %pM"
@@ -499,6 +516,14 @@ ieee80211_associate(struct ieee80211_work *wk)
 	struct ieee80211_sub_if_data *sdata = wk->sdata;
 	struct ieee80211_local *local = sdata->local;
 
+	if (!wk->assoc.synced) {
+		int ret = drv_tx_sync(local, sdata, wk->filter_ta,
+				      IEEE80211_TX_SYNC_ASSOC);
+		if (ret)
+			return WORK_ACT_TIMEOUT;
+	}
+	wk->assoc.synced = true;
+
 	wk->assoc.tries++;
 	if (wk->assoc.tries > IEEE80211_ASSOC_MAX_TRIES) {
 		printk(KERN_DEBUG "%s: association with %pM"