mac80211: temporarily disable reorder release timer
Several serve threading problems in 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 imminent advent of a new -rc cycle, it was
decided to disable the feature for the time being.
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index b67221d..902b03ee 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -622,6 +622,26 @@
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
+ *
+ * What was wrong:
+ * => 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 what needs to be fixed:
+ * => 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 +660,10 @@
} else {
del_timer(&tid_agg_rx->reorder_timer);
}
+ */
+
+set_release_timer:
+ return;
}
/*