[PATCH v3 1/9] mac80211: minstrel_ht: clean up CCK code

Felix Fietkau
2021-01-15T12:04:00Z

- move ack overhead out of rate duration table
- remove cck_supported, cck_supported_short

Preparation for adding OFDM legacy rates support

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
net/mac80211/rc80211_minstrel_ht.c | 54 +++++++++++++++++-------------
net/mac80211/rc80211_minstrel_ht.h | 5 ++-
2 files changed, 32 insertions(+), 27 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index b11a2af55b06..167d4fa5adf1 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -136,20 +136,16 @@
__VHT_GROUP(_streams, _sgi, _bw, \
VHT_GROUP_SHIFT(_streams, _sgi, _bw))

-#define CCK_DURATION(_bitrate, _short, _len) \
+#define CCK_DURATION(_bitrate, _short) \
(1000 * (10 /* SIFS */ + \
(_short ? 72 + 24 : 144 + 48) + \
- (8 * (_len + 4) * 10) / (_bitrate)))
-
-#define CCK_ACK_DURATION(_bitrate, _short) \
- (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
- CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
+ (8 * (AVG_PKT_SIZE + 4) * 10) / (_bitrate)))

#define CCK_DURATION_LIST(_short, _s) \
- CCK_ACK_DURATION(10, _short) >> _s, \
- CCK_ACK_DURATION(20, _short) >> _s, \
- CCK_ACK_DURATION(55, _short) >> _s, \
- CCK_ACK_DURATION(110, _short) >> _s
+ CCK_DURATION(10, _short) >> _s, \
+ CCK_DURATION(20, _short) >> _s, \
+ CCK_DURATION(55, _short) >> _s, \
+ CCK_DURATION(110, _short) >> _s

#define __CCK_GROUP(_s) \
[MINSTREL_CCK_GROUP] = { \
@@ -163,7 +159,7 @@
}

#define CCK_GROUP_SHIFT \
- GROUP_SHIFT(CCK_ACK_DURATION(10, false))
+ GROUP_SHIFT(CCK_DURATION(10, false))

#define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)

@@ -349,15 +345,19 @@ int
minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
int prob_avg)
{
- unsigned int nsecs = 0;
+ unsigned int nsecs = 0, overhead = mi->overhead;
+ unsigned int ampdu_len = 1;

/* do not account throughput if sucess prob is below 10% */
if (prob_avg < MINSTREL_FRAC(10, 100))
return 0;

- if (group != MINSTREL_CCK_GROUP)
- nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi);
+ if (group == MINSTREL_CCK_GROUP)
+ overhead = mi->overhead_legacy;
+ else
+ ampdu_len = minstrel_ht_avg_ampdu_len(mi);

+ nsecs = 1000 * overhead / ampdu_len;
nsecs += minstrel_mcs_groups[group].duration[rate] <<
minstrel_mcs_groups[group].shift;

@@ -1031,7 +1031,10 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
ctime += (t_slot * cw) >> 1;
cw = min((cw << 1) | 1, mp->cw_max);

- if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
+ if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
+ overhead = mi->overhead_legacy;
+ overhead_rtscts = mi->overhead_legacy_rtscts;
+ } else {
overhead = mi->overhead;
overhead_rtscts = mi->overhead_rtscts;
}
@@ -1369,18 +1372,14 @@ minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
return;

- mi->cck_supported = 0;
- mi->cck_supported_short = 0;
for (i = 0; i < 4; i++) {
if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
continue;

- mi->cck_supported |= BIT(i);
+ mi->supported[MINSTREL_CCK_GROUP] |= BIT(i);
if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
- mi->cck_supported_short |= BIT(i);
+ mi->supported[MINSTREL_CCK_GROUP] |= BIT(i + 4);
}
-
- mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported;
}

static void
@@ -1394,12 +1393,13 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
u16 ht_cap = sta->ht_cap.cap;
struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
+ const struct ieee80211_rate *ctl_rate;
+ bool ldpc, erp;
int use_vht;
int n_supported = 0;
int ack_dur;
int stbc;
int i;
- bool ldpc;

/* fall back to the old minstrel for legacy stations */
if (!sta->ht_cap.ht_supported)
@@ -1423,6 +1423,14 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
mi->overhead += ack_dur;
mi->overhead_rtscts = mi->overhead + 2 * ack_dur;

+ ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)];
+ erp = ctl_rate->flags & IEEE80211_RATE_ERP_G;
+ ack_dur = ieee80211_frame_duration(sband->band, 10,
+ ctl_rate->bitrate, erp, 1,
+ ieee80211_chandef_get_shift(chandef));
+ mi->overhead_legacy = ack_dur;
+ mi->overhead_legacy_rtscts = mi->overhead_legacy + 2 * ack_dur;
+
mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);

/* When using MRR, sample more on the first attempt, without delay */
@@ -1523,8 +1531,6 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
if (!n_supported)
goto use_legacy;

- mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4;
-
/* create an initial rate table with the lowest supported rates */
minstrel_ht_update_stats(mp, mi, true);
minstrel_ht_update_rates(mp, mi);
diff --git a/net/mac80211/rc80211_minstrel_ht.h b/net/mac80211/rc80211_minstrel_ht.h
index 53ea3c29debf..11300fa48a2f 100644
--- a/net/mac80211/rc80211_minstrel_ht.h
+++ b/net/mac80211/rc80211_minstrel_ht.h
@@ -77,6 +77,8 @@ struct minstrel_ht_sta {
/* overhead time in usec for each frame */
unsigned int overhead;
unsigned int overhead_rtscts;
+ unsigned int overhead_legacy;
+ unsigned int overhead_legacy_rtscts;

unsigned int total_packets_last;
unsigned int total_packets_cur;
@@ -97,9 +99,6 @@ struct minstrel_ht_sta {
/* current MCS group to be sampled */
u8 sample_group;

- u8 cck_supported;
- u8 cck_supported_short;
-
/* Bitfield of supported MCS rates of all groups */
u16 supported[MINSTREL_GROUPS_NB];

--
2.28.0