mac80211: do not compute offset from ssn in Rx AMPDU reordering buffer
Currently, frames that go into the reordering buffer are stored at
index ieee80211_sn_sub(sn, tid_rx->ssn) % tid_rx->buf_size.
The offset calculation to the starting sequence number (SSN) is
useless and just adds overhead so simply use sn % tid_rx->buf_size.
This means the reordering buffer will start to be filled somewhere
in the middle (at SSN % buf_size) and continue to get used from
there, but there's no reason to start from the beginning.
Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
[rewrite commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index caecef8..401f3c2 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -729,9 +729,7 @@
lockdep_assert_held(&tid_agg_rx->reorder_lock);
while (ieee80211_sn_less(tid_agg_rx->head_seq_num, head_seq_num)) {
- index = ieee80211_sn_sub(tid_agg_rx->head_seq_num,
- tid_agg_rx->ssn) %
- tid_agg_rx->buf_size;
+ index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
frames);
}
@@ -757,8 +755,7 @@
lockdep_assert_held(&tid_agg_rx->reorder_lock);
/* release the buffer until next missing frame */
- index = ieee80211_sn_sub(tid_agg_rx->head_seq_num,
- tid_agg_rx->ssn) % tid_agg_rx->buf_size;
+ index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
if (!tid_agg_rx->reorder_buf[index] &&
tid_agg_rx->stored_mpdu_num) {
/*
@@ -793,15 +790,11 @@
} else while (tid_agg_rx->reorder_buf[index]) {
ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
frames);
- index = ieee80211_sn_sub(tid_agg_rx->head_seq_num,
- tid_agg_rx->ssn) %
- tid_agg_rx->buf_size;
+ index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
}
if (tid_agg_rx->stored_mpdu_num) {
- j = index = ieee80211_sn_sub(tid_agg_rx->head_seq_num,
- tid_agg_rx->ssn) %
- tid_agg_rx->buf_size;
+ j = index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
for (; j != (index - 1) % tid_agg_rx->buf_size;
j = (j + 1) % tid_agg_rx->buf_size) {
@@ -861,8 +854,7 @@
/* Now the new frame is always in the range of the reordering buffer */
- index = ieee80211_sn_sub(mpdu_seq_num,
- tid_agg_rx->ssn) % tid_agg_rx->buf_size;
+ index = mpdu_seq_num % tid_agg_rx->buf_size;
/* check if we already stored this frame */
if (tid_agg_rx->reorder_buf[index]) {