[11/22] mac80211: fix race between next beacon dtim and ieee80211_get_buffered_bc

Commit Message

Jussi Kivilinna Jan. 31, 2011, 6:48 p.m. UTC

None

Patch

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index c47d7c0..f71ed31 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -225,6 +225,7 @@  struct ieee80211_if_ap {
 	struct sk_buff_head ps_bc_buf;
 	atomic_t num_sta_ps; /* number of stations in PS mode */
 	int dtim_count;
+	bool dtim_bc_mc;
 };
 
 struct ieee80211_if_wds {
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index ffc6749..1c8cf41 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2178,6 +2178,8 @@  static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
 	if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
 		aid0 = 1;
 
+	bss->dtim_bc_mc = aid0 == 1;
+
 	if (have_bits) {
 		/* Find largest even number N1 so that bits numbered 1 through
 		 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
@@ -2548,7 +2550,7 @@  ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
 	if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
 		goto out;
 
-	if (bss->dtim_count != 0)
+	if (bss->dtim_count != 0 || !bss->dtim_bc_mc)
 		goto out; /* send buffered bc/mc only after DTIM beacon */
 
 	while (1) {