mac80211: split TX aggregation stop action

When TX aggregation is stopped, there are a few
different cases:
 - connection with the peer was dropped
 - session stop was requested locally
 - session stop was requested by the peer
 - connection was dropped while a session is stopping

The behaviour in these cases should be different, if
the connection is dropped then the driver should drop
all frames, otherwise the frames may continue to be
transmitted, aggregated in the case of a locally
requested session stop or unaggregated in the case of
the peer requesting session stop.

Split these different cases so that the driver can
act accordingly; however, treat local and remote stop
the same way and ask the driver to not send frames as
aggregated packets any more.

In the case of connection drop, the stop callback the
driver is otherwise supposed to call is no longer
required.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 17 insertions, 5 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 0978b0faa880..a464f4fb36a0 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2033,17 +2033,29 @@ enum ieee80211_filter_flags {
  * calling ieee80211_start_tx_ba_cb_irqsafe, because the peer
  * might receive the addBA frame and send a delBA right away!
  *
- * @IEEE80211_AMPDU_RX_START: start Rx aggregation
- * @IEEE80211_AMPDU_RX_STOP: stop Rx aggregation
- * @IEEE80211_AMPDU_TX_START: start Tx aggregation
- * @IEEE80211_AMPDU_TX_STOP: stop Tx aggregation
+ * @IEEE80211_AMPDU_RX_START: start RX aggregation
+ * @IEEE80211_AMPDU_RX_STOP: stop RX aggregation
+ * @IEEE80211_AMPDU_TX_START: start TX aggregation
  * @IEEE80211_AMPDU_TX_OPERATIONAL: TX aggregation has become operational
+ * @IEEE80211_AMPDU_TX_STOP_CONT: stop TX aggregation but continue transmitting
+ *	queued packets, now unaggregated. After all packets are transmitted the
+ *	driver has to call ieee80211_stop_tx_ba_cb_irqsafe().
+ * @IEEE80211_AMPDU_TX_STOP_FLUSH: stop TX aggregation and flush all packets,
+ *	called when the station is removed. There's no need or reason to call
+ *	ieee80211_stop_tx_ba_cb_irqsafe() in this case as mac80211 assumes the
+ *	session is gone and removes the station.
+ * @IEEE80211_AMPDU_TX_STOP_FLUSH_CONT: called when TX aggregation is stopped
+ *	but the driver hasn't called ieee80211_stop_tx_ba_cb_irqsafe() yet and
+ *	now the connection is dropped and the station will be removed. Drivers
+ *	should clean up and drop remaining packets when this is called.
  */
 enum ieee80211_ampdu_mlme_action {
 	IEEE80211_AMPDU_RX_START,
 	IEEE80211_AMPDU_RX_STOP,
 	IEEE80211_AMPDU_TX_START,
-	IEEE80211_AMPDU_TX_STOP,
+	IEEE80211_AMPDU_TX_STOP_CONT,
+	IEEE80211_AMPDU_TX_STOP_FLUSH,
+	IEEE80211_AMPDU_TX_STOP_FLUSH_CONT,
 	IEEE80211_AMPDU_TX_OPERATIONAL,
 };