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Commit 438b61b7 authored by Simon Wunderlich's avatar Simon Wunderlich Committed by Johannes Berg
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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: default avatarSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: default avatarMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
parent 3de805cf

net/mac80211/ieee80211_i.h

+30 −1
Original line number Diff line number Diff line
@@ -812,6 +812,34 @@ ieee80211_get_sdata_band(struct ieee80211_sub_if_data *sdata) 
	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 @@ 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 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);

net/mac80211/rc80211_minstrel.c

+24 −6
Original line number Diff line number Diff line
@@ -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 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 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, 
	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 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, 
		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 @@ minstrel_init_cck_rates(struct minstrel_priv *mp) 
{

	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 @@ minstrel_init_cck_rates(struct minstrel_priv *mp) 
		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;

net/mac80211/rc80211_minstrel_ht.c

+3 −2
Original line number Diff line number Diff line
@@ -862,8 +862,9 @@ 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;

	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);

net/mac80211/tx.c

+7 −3
Original line number Diff line number Diff line
@@ -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, shift;

	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;

	}



	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 @@ 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,

				shift);



	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,

				shift);

	}



	return cpu_to_le16(dur);

net/mac80211/util.c

+26 −13
Original line number Diff line number Diff line
@@ -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 shift)

{

	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.

	 *

	 * 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 @@ 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 *= 1 << shift;

	} 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, shift = 0;

	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;

		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 @@ __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, shift = 0;

	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;

		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 @@ __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, shift = 0;

	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;

		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);