mac80211: fix timing for 5 MHz and 10 MHz channels
according to IEEE 802.11-2012 section 18, various timings change
when using 5 MHz and 10 MHz. Reflect this by using a "shift" when
calculating durations.
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 683751a..338e7ca 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -812,6 +812,34 @@
return band;
}
+static inline int
+ieee80211_chandef_get_shift(struct cfg80211_chan_def *chandef)
+{
+ switch (chandef->width) {
+ case NL80211_CHAN_WIDTH_5:
+ return 2;
+ case NL80211_CHAN_WIDTH_10:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static inline int
+ieee80211_vif_get_shift(struct ieee80211_vif *vif)
+{
+ struct ieee80211_chanctx_conf *chanctx_conf;
+ int shift = 0;
+
+ rcu_read_lock();
+ chanctx_conf = rcu_dereference(vif->chanctx_conf);
+ if (chanctx_conf)
+ shift = ieee80211_chandef_get_shift(&chanctx_conf->def);
+ rcu_read_unlock();
+
+ return shift;
+}
+
enum sdata_queue_type {
IEEE80211_SDATA_QUEUE_TYPE_FRAME = 0,
IEEE80211_SDATA_QUEUE_AGG_START = 1,
@@ -1468,7 +1496,8 @@
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 shift);
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 5b25966..a507376 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -382,14 +382,18 @@
static void
calc_rate_durations(enum ieee80211_band band,
struct minstrel_rate *d,
- struct ieee80211_rate *rate)
+ struct ieee80211_rate *rate,
+ struct cfg80211_chan_def *chandef)
{
int erp = !!(rate->flags & IEEE80211_RATE_ERP_G);
+ int shift = ieee80211_chandef_get_shift(chandef);
d->perfect_tx_time = ieee80211_frame_duration(band, 1200,
- rate->bitrate, erp, 1);
+ DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1,
+ shift);
d->ack_time = ieee80211_frame_duration(band, 10,
- rate->bitrate, erp, 1);
+ DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1,
+ shift);
}
static void
@@ -425,14 +429,17 @@
struct ieee80211_rate *ctl_rate;
unsigned int i, n = 0;
unsigned int t_slot = 9; /* FIXME: get real slot time */
+ u32 rate_flags;
mi->sta = sta;
mi->lowest_rix = rate_lowest_index(sband, sta);
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_chandef_get_shift(chandef));
+ rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
memset(mi->max_tp_rate, 0, sizeof(mi->max_tp_rate));
mi->max_prob_rate = 0;
@@ -441,15 +448,22 @@
unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0;
unsigned int tx_time_single;
unsigned int cw = mp->cw_min;
+ int shift;
if (!rate_supported(sta, sband->band, i))
continue;
+ if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
+ continue;
+
n++;
memset(mr, 0, sizeof(*mr));
mr->rix = i;
- mr->bitrate = sband->bitrates[i].bitrate / 5;
- calc_rate_durations(sband->band, mr, &sband->bitrates[i]);
+ shift = ieee80211_chandef_get_shift(chandef);
+ mr->bitrate = DIV_ROUND_UP(sband->bitrates[i].bitrate,
+ (1 << shift) * 5);
+ calc_rate_durations(sband->band, mr, &sband->bitrates[i],
+ chandef);
/* calculate maximum number of retransmissions before
* fallback (based on maximum segment size) */
@@ -547,6 +561,7 @@
{
static const int bitrates[4] = { 10, 20, 55, 110 };
struct ieee80211_supported_band *sband;
+ u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
int i, j;
sband = mp->hw->wiphy->bands[IEEE80211_BAND_2GHZ];
@@ -559,6 +574,9 @@
if (rate->flags & IEEE80211_RATE_ERP_G)
continue;
+ if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
+ continue;
+
for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
if (rate->bitrate != bitrates[j])
continue;
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 5256297..7475a7a 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -862,8 +862,9 @@
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;
+ ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
+ mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
+ mi->overhead += 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 4105d0c..3523daa 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -40,7 +40,7 @@
struct sk_buff *skb, int group_addr,
int next_frag_len)
{
- int rate, mrate, erp, dur, i;
+ int rate, mrate, erp, dur, i, shift;
struct ieee80211_rate *txrate;
struct ieee80211_local *local = tx->local;
struct ieee80211_supported_band *sband;
@@ -153,6 +153,8 @@
rate = mrate;
}
+ shift = ieee80211_vif_get_shift(&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 @@
* (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,
+ shift);
if (next_frag_len) {
/* Frame is fragmented: duration increases with time needed to
@@ -171,7 +174,8 @@
/* 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,
+ shift);
}
return cpu_to_le16(dur);
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 2265445..61856e1 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -107,7 +107,8 @@
}
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 shift)
{
int dur;
@@ -118,6 +119,9 @@
*
* rate is in 100 kbps, so divident is multiplied by 10 in the
* DIV_ROUND_UP() operations.
+ *
+ * shift may be 2 for 5 MHz channels or 1 for 10 MHz channels, and
+ * is assumed to be 0 otherwise.
*/
if (band == IEEE80211_BAND_5GHZ || erp) {
@@ -130,15 +134,21 @@
* 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 *= 1 << shift;
} else {
/*
* 802.11b or 802.11g with 802.11b compatibility:
@@ -168,7 +178,7 @@
{
struct ieee80211_sub_if_data *sdata;
u16 dur;
- int erp;
+ int erp, shift = 0;
bool short_preamble = false;
erp = 0;
@@ -177,10 +187,11 @@
short_preamble = sdata->vif.bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
+ shift = ieee80211_vif_get_shift(vif);
}
dur = ieee80211_frame_duration(band, frame_len, rate->bitrate, erp,
- short_preamble);
+ short_preamble, shift);
return cpu_to_le16(dur);
}
@@ -194,7 +205,7 @@
struct ieee80211_rate *rate;
struct ieee80211_sub_if_data *sdata;
bool short_preamble;
- int erp;
+ int erp, shift = 0;
u16 dur;
struct ieee80211_supported_band *sband;
@@ -210,17 +221,18 @@
short_preamble = sdata->vif.bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
+ shift = ieee80211_vif_get_shift(vif);
}
/* CTS duration */
dur = ieee80211_frame_duration(sband->band, 10, rate->bitrate,
- erp, short_preamble);
+ erp, short_preamble, shift);
/* Data frame duration */
dur += ieee80211_frame_duration(sband->band, frame_len, rate->bitrate,
- erp, short_preamble);
+ erp, short_preamble, shift);
/* ACK duration */
dur += ieee80211_frame_duration(sband->band, 10, rate->bitrate,
- erp, short_preamble);
+ erp, short_preamble, shift);
return cpu_to_le16(dur);
}
@@ -235,7 +247,7 @@
struct ieee80211_rate *rate;
struct ieee80211_sub_if_data *sdata;
bool short_preamble;
- int erp;
+ int erp, shift = 0;
u16 dur;
struct ieee80211_supported_band *sband;
@@ -250,15 +262,16 @@
short_preamble = sdata->vif.bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
+ shift = ieee80211_vif_get_shift(vif);
}
/* Data frame duration */
dur = ieee80211_frame_duration(sband->band, frame_len, rate->bitrate,
- erp, short_preamble);
+ erp, short_preamble, shift);
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, shift);
}
return cpu_to_le16(dur);