[PATCH] mac80211: fix reordering of buffered broadcast packets

[PATCH] mac80211: fix reordering of buffered broadcast packets

[Felix Fietkau]

If the buffered broadcast queue contains packets, letting new packets bypass
that queue can lead to heavy reordering, since the driver is probably throttling
transmission of buffered multicast packets after beacons.

Keep buffering packets until the buffer has been cleared (and no client
is in powersave mode).

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/mac80211/tx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 582b3d49f891..cd35af38d81f 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -439,8 +439,8 @@ ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
 	if (ieee80211_hw_check(&tx->local->hw, QUEUE_CONTROL))
 		info->hw_queue = tx->sdata->vif.cab_queue;
 
-	/* no stations in PS mode */
-	if (!atomic_read(&ps->num_sta_ps))
+	/* no stations in PS mode and no buffered packets */
+	if (!atomic_read(&ps->num_sta_ps) && skb_queue_empty(&ps->bc_buf))
 		return TX_CONTINUE;
 
 	info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
-- 
2.17.0