mac80211: let flush() drop packets when possible

When roaming / suspending, it makes no sense to wait until
the transmit queues of the device are empty. In extreme
condition they can be starved (VO saturating the air), but
even in regular cases, it is pointless to delay the roaming
because the low level driver is trying to send packets to
an AP which is far away. We'd rather drop these packets and
let TCP retransmit if needed. This will allow to speed up
the roaming.

For suspend, the explanation is even more trivial.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 8354bedc858a..c0711082a2b8 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1604,7 +1604,7 @@ void ieee80211_dynamic_ps_enable_work(struct work_struct *work)
                 } else {
                         ieee80211_send_nullfunc(local, sdata, 1);
                         /* Flush to get the tx status of nullfunc frame */
-                        ieee80211_flush_queues(local, sdata);
+                        ieee80211_flush_queues(local, sdata, false);
                 }
         }
 
@@ -2011,18 +2011,23 @@ static void ieee80211_set_disassoc(struct ieee80211_sub_if_data *sdata,
         /* disable per-vif ps */
         ieee80211_recalc_ps_vif(sdata);
 
-        /* flush out any pending frame (e.g. DELBA) before deauth/disassoc */
+        /*
+         * drop any frame before deauth/disassoc, this can be data or
+         * management frame. Since we are disconnecting, we should not
+         * insist sending these frames which can take time and delay
+         * the disconnection and possible the roaming.
+         */
         if (tx)
-                ieee80211_flush_queues(local, sdata);
+                ieee80211_flush_queues(local, sdata, true);
 
         /* deauthenticate/disassociate now */
         if (tx || frame_buf)
                 ieee80211_send_deauth_disassoc(sdata, ifmgd->bssid, stype,
                                                reason, tx, frame_buf);
 
-        /* flush out frame */
+        /* flush out frame - make sure the deauth was actually sent */
         if (tx)
-                ieee80211_flush_queues(local, sdata);
+                ieee80211_flush_queues(local, sdata, false);
 
         /* clear bssid only after building the needed mgmt frames */
         memset(ifmgd->bssid, 0, ETH_ALEN);