4 files changed, 44 insertions, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 3f1b58cf9c8c..e3fa90ce9ecb 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2244,6 +2244,18 @@ enum ieee80211_rate_control_changed {
  * @get_rssi: Get current signal strength in dBm, the function is optional
  *      and can sleep.
  *
+ * @mgd_prepare_tx: Prepare for transmitting a management frame for association
+ *      before associated. In multi-channel scenarios, a virtual interface is
+ *      bound to a channel before it is associated, but as it isn't associated
+ *      yet it need not necessarily be given airtime, in particular since any
+ *      transmission to a P2P GO needs to be synchronized against the GO's
+ *      powersave state. mac80211 will call this function before transmitting a
+ *      management frame prior to having successfully associated to allow the
+ *      driver to give it channel time for the transmission, to get a response
+ *      and to be able to synchronize with the GO.
+ *      The callback will be called before each transmission and upon return
+ *      mac80211 will transmit the frame right away.
+ *      The callback is optional and can (should!) sleep.
  */
 struct ieee80211_ops {
         void (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb);
@@ -2383,6 +2395,9 @@ struct ieee80211_ops {
                                   u32 sset, u8 *data);
         int     (*get_rssi)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
                             struct ieee80211_sta *sta, s8 *rssi_dbm);
+
+        void    (*mgd_prepare_tx)(struct ieee80211_hw *hw,
+                                  struct ieee80211_vif *vif);
 };
 
 /**
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 5042151a3325..df9203199102 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -852,4 +852,18 @@ static inline int drv_get_rssi(struct ieee80211_local *local,
 
         return ret;
 }
+
+static inline void drv_mgd_prepare_tx(struct ieee80211_local *local,
+                                      struct ieee80211_sub_if_data *sdata)
+{
+        might_sleep();
+
+        check_sdata_in_driver(sdata);
+        WARN_ON_ONCE(sdata->vif.type != NL80211_IFTYPE_STATION);
+
+        trace_drv_mgd_prepare_tx(local, sdata);
+        if (local->ops->mgd_prepare_tx)
+                local->ops->mgd_prepare_tx(&local->hw, &sdata->vif);
+        trace_drv_return_void(local);
+}
 #endif /* __MAC80211_DRIVER_OPS */
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index e9c0d1b68fc8..d563f7c55531 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -541,6 +541,8 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
                 memcpy(pos, assoc_data->ie + offset, noffset - offset);
         }
 
+        drv_mgd_prepare_tx(local, sdata);
+
         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
         ieee80211_tx_skb(sdata, skb);
 }
@@ -580,6 +582,9 @@ static void ieee80211_send_deauth_disassoc(struct ieee80211_sub_if_data *sdata,
                 if (!(ifmgd->flags & IEEE80211_STA_MFP_ENABLED))
                         IEEE80211_SKB_CB(skb)->flags |=
                                 IEEE80211_TX_INTFL_DONT_ENCRYPT;
+
+                drv_mgd_prepare_tx(local, sdata);
+
                 ieee80211_tx_skb(sdata, skb);
         }
 }
@@ -1756,6 +1761,7 @@ static void ieee80211_auth_challenge(struct ieee80211_sub_if_data *sdata,
         if (!elems.challenge)
                 return;
         auth_data->expected_transaction = 4;
+        drv_mgd_prepare_tx(sdata->local, sdata);
         ieee80211_send_auth(sdata, 3, auth_data->algorithm,
                             elems.challenge - 2, elems.challenge_len + 2,
                             auth_data->bss->bssid, auth_data->bss->bssid,
@@ -2641,6 +2647,8 @@ static int ieee80211_probe_auth(struct ieee80211_sub_if_data *sdata)
                 return -ETIMEDOUT;
         }
 
+        drv_mgd_prepare_tx(local, sdata);
+
         if (auth_data->bss->proberesp_ies) {
                 sdata_info(sdata, "send auth to %pM (try %d/%d)\n",
                            auth_data->bss->bssid, auth_data->tries,
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index 2e60f4acd027..e1e9d10ec2e7 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -1244,6 +1244,13 @@ TRACE_EVENT(drv_get_rssi,
         )
 );
 
+DEFINE_EVENT(local_sdata_evt, drv_mgd_prepare_tx,
+        TP_PROTO(struct ieee80211_local *local,
+                 struct ieee80211_sub_if_data *sdata),
+
+        TP_ARGS(local, sdata)
+);
+
 /*
  * Tracing for API calls that drivers call.
  */