[PATCH] mac80211: temporarily disable reorder release timer

[PATCH] mac80211: temporarily disable reorder release timer

[Christian Lamparter]

Serve threading problems with the current release
reorder timer implementation have been discovered.

A lengthy discussion which lists some of the pitfalls
and possible solutions can be found at:
 http://marc.info/?t=128635927000001

But Due to the complicated nature of the subject and
the foreseeable advent of a new -rc1 cycle, it was
decided to disable the feature for the time being.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
---
if we want, we could add a WARN_ON into the timer too.
---
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index b67221d..e1e02b5 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -622,6 +622,26 @@ static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
 							tid_agg_rx->buf_size;
 	}
 
+	/*
+	 * Disable the reorder release timer for now.
+	 *
+	 * The current implementation lacks a proper locking scheme
+	 * which would protect vital statistic and debug counters
+	 * from being updated by two different, but concurrent BHs.
+	 *
+	 * more information about the topic is available from:
+	 * - thread: http://marc.info/?t=128635927000001
+	 *
+	 * Why did it break:
+	 * =>  http://marc.info/?l=linux-wireless&m=128636170811964
+	 * "Basically the thing is that until your patch, the data
+	 *  in the struct didn't actually need locking because it
+	 *  was accessed by the RX path only which is not concurrent."
+	 *
+	 * List of known things that need to be fixed/considered:
+	 * => http://marc.info/?l=linux-wireless&m=128656352920957
+	 *
+
 	if (tid_agg_rx->stored_mpdu_num) {
 		j = index = seq_sub(tid_agg_rx->head_seq_num,
 				    tid_agg_rx->ssn) % tid_agg_rx->buf_size;
@@ -640,6 +660,9 @@ static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
 	} else {
 		del_timer(&tid_agg_rx->reorder_timer);
 	}
+	 */
+
+set_release_timer:
 }
 
 /*