From 2e3049b79cb98018abc83383f9b737508240dd54 Mon Sep 17 00:00:00 2001 From: Karl Beldan Date: Thu, 24 Oct 2013 15:53:32 +0200 Subject: [PATCH] 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 [rewrite commit message] Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index caecef870c0e..401f3c26e707 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -729,9 +729,7 @@ static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata 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 @@ static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata, 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 @@ static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata, } 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 @@ static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata /* 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]) {