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mac80211: temporarily disable reorder release timer
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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>
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Christian Lamparter authored and John W. Linville committed Oct 11, 2010
1 parent d12c745 commit 15943a7
Showing 1 changed file with 24 additions and 0 deletions.
24 changes: 24 additions & 0 deletions net/mac80211/rx.c
Original file line number Diff line number Diff line change
Expand Up @@ -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
*
* 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;
Expand All @@ -640,6 +660,10 @@ static void ieee80211_sta_reorder_release(struct ieee80211_hw *hw,
} else {
del_timer(&tid_agg_rx->reorder_timer);
}
*/

set_release_timer:
return;
}

/*
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