mac80211: Fix the wrong WARN_ON message appearing on enabling power save.

This issue happens only when we are associated with a 11n AP and power save
is enabled. In the function 'ieee80211_master_start_xmit', ps_disable_work
is queued where wake_queues is called. But before this work is executed,
we check if the queues are stopped in _ieee80211_tx and return TX_AGAIN to
ieee8011_tx which leads to the warning message.
This patch fixes this erroneous case.

Signed-off-by: Vivek Natarajan <vnatarajan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index f1c726d94f47..bf73f6d561b7 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -35,6 +35,7 @@
 #define IEEE80211_TX_OK         0
 #define IEEE80211_TX_AGAIN      1
 #define IEEE80211_TX_FRAG_AGAIN 2
+#define IEEE80211_TX_PENDING    3
 
 /* misc utils */
 
@@ -1085,7 +1086,7 @@ static int __ieee80211_tx(struct ieee80211_local *local, struct sk_buff *skb,
 
         if (skb) {
                 if (netif_subqueue_stopped(local->mdev, skb))
-                        return IEEE80211_TX_AGAIN;
+                        return IEEE80211_TX_PENDING;
 
                 ret = local->ops->tx(local_to_hw(local), skb);
                 if (ret)
@@ -1211,8 +1212,9 @@ retry:
                  * queues, there's no reason for a driver to reject
                  * a frame there, warn and drop it.
                  */
-                if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
-                        goto drop;
+                if (ret != IEEE80211_TX_PENDING)
+                        if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
+                                goto drop;
 
                 store = &local->pending_packet[queue];