mac80211: Don't buffer non-bufferable MMPDUs

Non-bufferable MMPDUs are sent out to STAs even while in PS mode
(for example probe responses). Applying filtered frame handling for
these doesn't seem to make much sense and will only create more
air utilization when the STA wakes up. Hence, apply filtered frame
handling only for bufferable MMPDUs.

Discovered while testing an old VOIP phone that started probing
for APs while in PS mode. The mac80211/ath9k AP where the STA is
associated would reply with a probe response but the phone sometimes
moved to a new channel already and couldn't ack the probe response
anymore. In that case mac80211 applied filtered frame handling
for the un-acked probe response.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 5bad05e9af90fc76201f4bd9a54b931ffd5c61bc..6101deb805a830a80acccbe05499ca4f4fc33988 100644 (file)
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -51,6 +51,11 @@ static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
        struct ieee80211_hdr *hdr = (void *)skb->data;
        int ac;
 
+       if (info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER) {
+               ieee80211_free_txskb(&local->hw, skb);
+               return;
+       }
+
        /*
         * This skb 'survived' a round-trip through the driver, and
         * hopefully the driver didn't mangle it too badly. However,