Return-path: Received: from cora.hrz.tu-chemnitz.de ([134.109.228.40]:50020 "EHLO cora.hrz.tu-chemnitz.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752226Ab3EPLB6 (ORCPT ); Thu, 16 May 2013 07:01:58 -0400 From: Simon Wunderlich To: linux-wireless@vger.kernel.org Cc: Johannes Berg , Mathias Kretschmer , Simon Wunderlich Subject: [PATCHv3 05/18] mac80211: fix timing for 5 MHz and 10 MHz channels Date: Thu, 16 May 2013 13:00:32 +0200 Message-Id: <1368702045-27598-6-git-send-email-siwu@hrz.tu-chemnitz.de> (sfid-20130516_130212_212859_B97886E0) In-Reply-To: <1368702045-27598-1-git-send-email-siwu@hrz.tu-chemnitz.de> References: <1368702045-27598-1-git-send-email-siwu@hrz.tu-chemnitz.de> Sender: linux-wireless-owner@vger.kernel.org List-ID: 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 Signed-off-by: Mathias Kretschmer --- net/mac80211/ieee80211_i.h | 42 +++++++++++++++++++++++++++++++++++- net/mac80211/rc80211_minstrel.c | 15 ++++++++----- net/mac80211/rc80211_minstrel_ht.c | 8 ++++--- net/mac80211/tx.c | 10 ++++++--- net/mac80211/util.c | 39 ++++++++++++++++++++++----------- 5 files changed, 89 insertions(+), 25 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 158e6eb..0e8f2d0 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -793,6 +793,45 @@ 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..ffabe1d 100644 --- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -382,14 +382,18 @@ 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); + int divisor = ieee80211_hw_get_divisor(mp->hw); d->perfect_tx_time = ieee80211_frame_duration(band, 1200, - rate->bitrate, erp, 1); + DIV_ROUND_UP(rate->bitrate, divisor), erp, 1, + divisor); d->ack_time = ieee80211_frame_duration(band, 10, - rate->bitrate, erp, 1); + DIV_ROUND_UP(rate->bitrate, divisor), erp, 1, + divisor); } static void @@ -430,7 +434,8 @@ 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 +453,7 @@ 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 9972e07..e1f18a8 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 3f87fa4..5496764 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 +119,9 @@ 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. */ if (band == IEEE80211_BAND_5GHZ || erp) { @@ -130,15 +134,21 @@ 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 +178,7 @@ __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 +187,11 @@ __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 +205,7 @@ __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 +221,18 @@ __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 +247,7 @@ __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 +262,16 @@ __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