diff options
| author |   Daniel Halperin <dhalperi@cs.washington.edu> | 2011-05-10 19:00:45 -0700 |
|---|---|---|
| committer |   John W. Linville <linville@tuxdriver.com> | 2011-05-12 14:10:48 -0400 |
| commit | 8fddddff0ad4ccc2787464207eba9ed3063e69cd (patch) | |
| tree | 6f219c46e9fdae5df766deb784c3cfc00e3e4106 /net/mac80211/rc80211_minstrel.c | |
| parent | cfg80211: restrict AP beacon intervals (diff) | |
| download | linux-dev-8fddddff0ad4ccc2787464207eba9ed3063e69cd.tar.xz linux-dev-8fddddff0ad4ccc2787464207eba9ed3063e69cd.zip | |
mac80211: fix contention time computation in minstrel, minstrel_ht
When transmitting a frame, the transmitter waits a random number of
slots between 0 and cw. Thus, the contention time is (cw / 2) * t_slot
which we can represent instead as (cw * t_slot) >> 1. Also fix a few
other accounting bugs around contention time, and add comments.
Signed-off-by: Daniel Halperin <dhalperi@cs.washington.edu>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/rc80211_minstrel.c')
| -rw-r--r-- | net/mac80211/rc80211_minstrel.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c index 778c604d7939..8adac67395f7 100644 --- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -417,8 +417,8 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, tx_time_single = mr->ack_time + mr->perfect_tx_time; /* contention window */ - tx_time_single += t_slot + min(cw, mp->cw_max); - cw = (cw << 1) | 1; + tx_time_single += (t_slot * cw) >> 1; + cw = min((cw << 1) | 1, mp->cw_max); tx_time += tx_time_single; tx_time_cts += tx_time_single + mi->sp_ack_dur; |