From: Simon Wunderlich <siwu@xxxxxxxxxxxxxxxxxx>
according to IEEE 802.11-2012 section 18, various timings change
when using 5 MHz and 10 MHz. Reflect this by using a "divisor" when
calculating durations.
Signed-off-by: Simon Wunderlich <siwu@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@xxxxxxxxxxxxxxxxxxx>
---
net/mac80211/ieee80211_i.h | 42 ++++++++++++++++++++++++++++++++++-
net/mac80211/rc80211_minstrel.c | 14 +++++++-----
net/mac80211/rc80211_minstrel_ht.c | 8 ++++---
net/mac80211/tx.c | 10 ++++++---
net/mac80211/util.c | 43 +++++++++++++++++++++++++-----------
5 files changed, 92 insertions(+), 25 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 1079c27..e9d3da9 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -792,6 +792,45 @@ ieee80211_get_sdata_band(struct ieee80211_sub_if_data *sdata)
return band;
}
+static inline int
+ieee80211_vif_get_divisor(struct ieee80211_vif *vif)
+{
+ struct ieee80211_chanctx_conf *chanctx_conf;
+ int divisor = 1;
+
+ rcu_read_lock();
+ chanctx_conf = rcu_dereference(vif->chanctx_conf);
+ if (chanctx_conf) {
+ switch (chanctx_conf->def.width) {
+ case NL80211_CHAN_WIDTH_5:
+ divisor = 4;
+ break;
+ case NL80211_CHAN_WIDTH_10:
+ divisor = 2;
+ break;
+ default:
+ divisor = 1;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ return divisor;
+}
+
+static inline int
+ieee80211_hw_get_divisor(struct ieee80211_hw *hw)
+{
+ switch (hw->conf.chandef.width) {
+ case NL80211_CHAN_WIDTH_5:
+ return 4;
+ case NL80211_CHAN_WIDTH_10:
+ return 2;
+ default:
+ return 1;
+ }
+}
+
enum sdata_queue_type {
IEEE80211_SDATA_QUEUE_TYPE_FRAME = 0,
IEEE80211_SDATA_QUEUE_AGG_START = 1,
@@ -1448,7 +1487,8 @@ extern void *mac80211_wiphy_privid; /* for wiphy privid */
u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
enum nl80211_iftype type);
int ieee80211_frame_duration(enum ieee80211_band band, size_t len,
- int rate, int erp, int short_preamble);
+ int rate, int erp, int short_preamble,
+ int divisor);
void mac80211_ev_michael_mic_failure(struct ieee80211_sub_if_data *sdata, int keyidx,
struct ieee80211_hdr *hdr, const u8 *tsc,
gfp_t gfp);
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index ac7ef54..3fe134a 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -382,14 +382,17 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
static void
calc_rate_durations(enum ieee80211_band band,
struct minstrel_rate *d,
- struct ieee80211_rate *rate)
+ struct ieee80211_rate *rate,
+ struct minstrel_priv *mp)
{
int erp = !!(rate->flags & IEEE80211_RATE_ERP_G);
d->perfect_tx_time = ieee80211_frame_duration(band, 1200,
- rate->bitrate, erp, 1);
+ rate->bitrate, erp, 1,
+ ieee80211_hw_get_divisor(mp->hw));
d->ack_time = ieee80211_frame_duration(band, 10,
- rate->bitrate, erp, 1);
+ rate->bitrate, erp, 1,
+ ieee80211_hw_get_divisor(mp->hw));
}
static void
@@ -430,7 +433,8 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
ctl_rate = &sband->bitrates[mi->lowest_rix];
mi->sp_ack_dur = ieee80211_frame_duration(sband->band, 10,
ctl_rate->bitrate,
- !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1);
+ !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1,
+ ieee80211_hw_get_divisor(mp->hw));
memset(mi->max_tp_rate, 0, sizeof(mi->max_tp_rate));
mi->max_prob_rate = 0;
@@ -448,7 +452,7 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
mr->rix = i;
mr->bitrate = sband->bitrates[i].bitrate / 5;
- calc_rate_durations(sband->band, mr, &sband->bitrates[i]);
+ calc_rate_durations(sband->band, mr, &sband->bitrates[i], mp);
/* calculate maximum number of retransmissions before
* fallback (based on maximum segment size) */
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 5b2d301..f05eeff 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -844,7 +844,7 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
u16 sta_cap = sta->ht_cap.cap;
int n_supported = 0;
- int ack_dur;
+ int ack_dur, divisor;
int stbc;
int i;
@@ -861,8 +861,10 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
mi->sta = sta;
mi->stats_update = jiffies;
- ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1);
- mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1) + ack_dur;
+ divisor = ieee80211_hw_get_divisor(mp->hw);
+ ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, divisor);
+ mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1,
+ divisor) + ack_dur;
mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 4a5fbf8..4bed9fd 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -40,7 +40,7 @@ static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
struct sk_buff *skb, int group_addr,
int next_frag_len)
{
- int rate, mrate, erp, dur, i;
+ int rate, mrate, erp, dur, i, divisor;
struct ieee80211_rate *txrate;
struct ieee80211_local *local = tx->local;
struct ieee80211_supported_band *sband;
@@ -153,6 +153,8 @@ static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
rate = mrate;
}
+ divisor = ieee80211_vif_get_divisor(&tx->sdata->vif);
+
/* Don't calculate ACKs for QoS Frames with NoAck Policy set */
if (ieee80211_is_data_qos(hdr->frame_control) &&
*(ieee80211_get_qos_ctl(hdr)) & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
@@ -162,7 +164,8 @@ static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
* (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
* to closest integer */
dur = ieee80211_frame_duration(sband->band, 10, rate, erp,
- tx->sdata->vif.bss_conf.use_short_preamble);
+ tx->sdata->vif.bss_conf.use_short_preamble,
+ divisor);
if (next_frag_len) {
/* Frame is fragmented: duration increases with time needed to
@@ -171,7 +174,8 @@ static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
/* next fragment */
dur += ieee80211_frame_duration(sband->band, next_frag_len,
txrate->bitrate, erp,
- tx->sdata->vif.bss_conf.use_short_preamble);
+ tx->sdata->vif.bss_conf.use_short_preamble,
+ divisor);
}
return cpu_to_le16(dur);
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 27e0715..ad03800 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -107,7 +107,8 @@ void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx)
}
int ieee80211_frame_duration(enum ieee80211_band band, size_t len,
- int rate, int erp, int short_preamble)
+ int rate, int erp, int short_preamble,
+ int divisor)
{
int dur;
@@ -118,6 +119,13 @@ int ieee80211_frame_duration(enum ieee80211_band band, size_t len,
*
* rate is in 100 kbps, so divident is multiplied by 10 in the
* DIV_ROUND_UP() operations.
+ *
+ * divisor may be 4 for 5 MHz channels or 2 for 1 MHz channels, and
+ * is assumed to be 1 otherwise. For 5 and 10 MHz channels, the
+ * according 20 MHz rates are assumed. For example, a datarate of
+ * 1.5mbps in a 5 MHz channel would be reported as rate == 60,
+ * because the corresponding datarate in 20mbps with the same
+ * modulation would be 6 mbps.
*/
if (band == IEEE80211_BAND_5GHZ || erp) {
@@ -130,15 +138,21 @@ int ieee80211_frame_duration(enum ieee80211_band band, size_t len,
* TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
*
* T_SYM = 4 usec
- * 802.11a - 17.5.2: aSIFSTime = 16 usec
+ * 802.11a - 18.5.2: aSIFSTime = 16 usec
* 802.11g - 19.8.4: aSIFSTime = 10 usec +
* signal ext = 6 usec
*/
dur = 16; /* SIFS + signal ext */
- dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
- dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
+ dur += 16; /* IEEE 802.11-2012 18.3.2.4: T_PREAMBLE = 16 usec */
+ dur += 4; /* IEEE 802.11-2012 18.3.2.4: T_SIGNAL = 4 usec */
dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
4 * rate); /* T_SYM x N_SYM */
+
+ /* IEEE 802.11-2012 18.3.2.4: all values above are:
+ * * times 4 for 5 MHz
+ * * times 2 for 10 MHz
+ */
+ dur *= divisor;
} else {
/*
* 802.11b or 802.11g with 802.11b compatibility:
@@ -168,7 +182,7 @@ __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
{
struct ieee80211_sub_if_data *sdata;
u16 dur;
- int erp;
+ int erp, divisor = 1;
bool short_preamble = false;
erp = 0;
@@ -177,10 +191,11 @@ __le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
short_preamble = sdata->vif.bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
+ divisor = ieee80211_vif_get_divisor(vif);
}
dur = ieee80211_frame_duration(band, frame_len, rate->bitrate, erp,
- short_preamble);
+ short_preamble, divisor);
return cpu_to_le16(dur);
}
@@ -194,7 +209,7 @@ __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
struct ieee80211_rate *rate;
struct ieee80211_sub_if_data *sdata;
bool short_preamble;
- int erp;
+ int erp, divisor = 1;
u16 dur;
struct ieee80211_supported_band *sband;
@@ -210,17 +225,18 @@ __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
short_preamble = sdata->vif.bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
+ divisor = ieee80211_vif_get_divisor(vif);
}
/* CTS duration */
dur = ieee80211_frame_duration(sband->band, 10, rate->bitrate,
- erp, short_preamble);
+ erp, short_preamble, divisor);
/* Data frame duration */
dur += ieee80211_frame_duration(sband->band, frame_len, rate->bitrate,
- erp, short_preamble);
+ erp, short_preamble, divisor);
/* ACK duration */
dur += ieee80211_frame_duration(sband->band, 10, rate->bitrate,
- erp, short_preamble);
+ erp, short_preamble, divisor);
return cpu_to_le16(dur);
}
@@ -235,7 +251,7 @@ __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
struct ieee80211_rate *rate;
struct ieee80211_sub_if_data *sdata;
bool short_preamble;
- int erp;
+ int erp, divisor = 1;
u16 dur;
struct ieee80211_supported_band *sband;
@@ -250,15 +266,16 @@ __le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
short_preamble = sdata->vif.bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
+ divisor = ieee80211_vif_get_divisor(vif);
}
/* Data frame duration */
dur = ieee80211_frame_duration(sband->band, frame_len, rate->bitrate,
- erp, short_preamble);
+ erp, short_preamble, divisor);
if (!(frame_txctl->flags & IEEE80211_TX_CTL_NO_ACK)) {
/* ACK duration */
dur += ieee80211_frame_duration(sband->band, 10, rate->bitrate,
- erp, short_preamble);
+ erp, short_preamble, divisor);
}
return cpu_to_le16(dur);
--
1.7.10.4
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