mac80211: send (QoS) Null if no buffered frames

For PS-poll, there's a possible race between
us expiring a frame and the station polling
for it -- send it a null frame in that case.

For uAPSD, the standard says that we have to
send a frame in each SP, so send null if we
don't have any other frames.

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

1 files changed, 1 insertions, 2 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index a0676d39fe8f..5bf91c43c88c 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1520,8 +1520,7 @@ static int ieee80211_skb_resize(struct ieee80211_sub_if_data *sdata,
         return 0;
 }
 
-static void ieee80211_xmit(struct ieee80211_sub_if_data *sdata,
-                           struct sk_buff *skb)
+void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 {
         struct ieee80211_local *local = sdata->local;
         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);