4 files changed, 46 insertions, 8 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 965f1b16e53a..361bc5d85b1a 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1819,6 +1819,9 @@ enum ieee80211_ampdu_mlme_action {
  * @set_ringparam: Set tx and rx ring sizes.
  *
  * @get_ringparam: Get tx and rx ring current and maximum sizes.
+ *
+ * @tx_frames_pending: Check if there is any pending frame in the hardware
+ *      queues before entering power save.
  */
 struct ieee80211_ops {
         void (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb);
@@ -1906,6 +1909,7 @@ struct ieee80211_ops {
         int (*set_ringparam)(struct ieee80211_hw *hw, u32 tx, u32 rx);
         void (*get_ringparam)(struct ieee80211_hw *hw,
                               u32 *tx, u32 *tx_max, u32 *rx, u32 *rx_max);
+        bool (*tx_frames_pending)(struct ieee80211_hw *hw);
 };
 
 /**
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 9c0d62bb0ea3..00a0685f2403 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -552,4 +552,17 @@ static inline void drv_get_ringparam(struct ieee80211_local *local,
         trace_drv_return_void(local);
 }
 
+static inline bool drv_tx_frames_pending(struct ieee80211_local *local)
+{
+        bool ret = false;
+
+        might_sleep();
+
+        trace_drv_tx_frames_pending(local);
+        if (local->ops->tx_frames_pending)
+                ret = local->ops->tx_frames_pending(&local->hw);
+        trace_drv_return_bool(local, ret);
+
+        return ret;
+}
 #endif /* __MAC80211_DRIVER_OPS */
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index 45aab80738e2..c8c934d48b7a 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -74,6 +74,21 @@ TRACE_EVENT(drv_return_int,
         TP_printk(LOCAL_PR_FMT " - %d", LOCAL_PR_ARG, __entry->ret)
 );
 
+TRACE_EVENT(drv_return_bool,
+        TP_PROTO(struct ieee80211_local *local, bool ret),
+        TP_ARGS(local, ret),
+        TP_STRUCT__entry(
+                LOCAL_ENTRY
+                __field(bool, ret)
+        ),
+        TP_fast_assign(
+                LOCAL_ASSIGN;
+                __entry->ret = ret;
+        ),
+        TP_printk(LOCAL_PR_FMT " - %s", LOCAL_PR_ARG, (__entry->ret) ?
+                  "true" : "false")
+);
+
 TRACE_EVENT(drv_return_u64,
         TP_PROTO(struct ieee80211_local *local, u64 ret),
         TP_ARGS(local, ret),
@@ -964,6 +979,11 @@ TRACE_EVENT(drv_get_ringparam,
         )
 );
 
+DEFINE_EVENT(local_only_evt, drv_tx_frames_pending,
+        TP_PROTO(struct ieee80211_local *local),
+        TP_ARGS(local)
+);
+
 DEFINE_EVENT(local_only_evt, drv_offchannel_tx_cancel_wait,
         TP_PROTO(struct ieee80211_local *local),
         TP_ARGS(local)
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 865fed4cc18b..a41f234bd486 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -761,15 +761,16 @@ void ieee80211_dynamic_ps_enable_work(struct work_struct *work)
         if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
             (!(ifmgd->flags & IEEE80211_STA_NULLFUNC_ACKED))) {
                 netif_tx_stop_all_queues(sdata->dev);
-                /*
-                 * Flush all the frames queued in the driver before
-                 * going to power save
-                 */
-                drv_flush(local, false);
-                ieee80211_send_nullfunc(local, sdata, 1);
 
-                /* Flush once again to get the tx status of nullfunc frame */
-                drv_flush(local, false);
+                if (drv_tx_frames_pending(local))
+                        mod_timer(&local->dynamic_ps_timer, jiffies +
+                                  msecs_to_jiffies(
+                                  local->hw.conf.dynamic_ps_timeout));
+                else {
+                        ieee80211_send_nullfunc(local, sdata, 1);
+                        /* Flush to get the tx status of nullfunc frame */
+                        drv_flush(local, false);
+                }
         }
 
         if (!((local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&