1 files changed, 0 insertions, 481 deletions
diff --git a/package/kernel/mac80211/patches/subsys/366-mac80211-minstrel_ht-improve-rate-probing-for-device.patch b/package/kernel/mac80211/patches/subsys/366-mac80211-minstrel_ht-improve-rate-probing-for-device.patch
deleted file mode 100644
index 2dd57e0f22..0000000000
--- a/package/kernel/mac80211/patches/subsys/366-mac80211-minstrel_ht-improve-rate-probing-for-device.patch
+++ /dev/null
@@ -1,481 +0,0 @@
-From: Felix Fietkau <nbd@nbd.name>
-Date: Fri, 14 Jun 2019 21:15:47 +0200
-Subject: [PATCH] mac80211: minstrel_ht: improve rate probing for devices
- with static fallback
-
-On some devices that only support static rate fallback tables sending rate
-control probing packets can be really expensive.
-Probing lower rates can already hurt throughput quite a bit. What hurts even
-more is the fact that on mt76x0/mt76x2, single probing packets can only be
-forced by directing packets at a different internal hardware queue, which
-causes some heavy reordering and extra latency.
-The reordering issue is mainly problematic while pushing lots of packets to
-a particular station. If there is little activity, the overhead of probing is
-neglegible.
-
-The static fallback behavior is designed to pretty much only handle rate
-control algorithms that use only a very limited set of rates on which the
-algorithm switches up/down based on packet error rate.
-
-In order to better support that kind of hardware, this patch implements a
-different approach to rate probing where it switches to a slightly higher rate,
-waits for tx status feedback, then updates the stats and switches back to
-the new max throughput rate. This only triggers above a packet rate of 100
-per stats interval (~50ms).
-For that kind of probing, the code has to reduce the set of probing rates
-a lot more compared to single packet probing, so it uses only one packet
-per MCS group which is either slightly faster, or as close as possible to
-the max throughput rate.
-This allows switching between similar rates with different numbers of
-streams. The algorithm assumes that the hardware will work its way lower
-within an MCS group in case of retransmissions, so that lower rates don't
-have to be probed by the high packets per second rate probing code.
-
-To further reduce the search space, it also does not probe rates with lower
-channel bandwidth than the max throughput rate.
-
-At the moment, these changes will only affect mt76x0/mt76x2.
-
-Signed-off-by: Felix Fietkau <nbd@nbd.name>
----
-
---- a/net/mac80211/rc80211_minstrel.h
-+++ b/net/mac80211/rc80211_minstrel.h
-@@ -114,6 +114,7 @@ struct minstrel_sta_info {
- struct minstrel_priv {
- 	struct ieee80211_hw *hw;
- 	bool has_mrr;
-+	u32 sample_switch;
- 	unsigned int cw_min;
- 	unsigned int cw_max;
- 	unsigned int max_retry;
---- a/net/mac80211/rc80211_minstrel_ht.c
-+++ b/net/mac80211/rc80211_minstrel_ht.c
-@@ -21,6 +21,8 @@
- #define AVG_AMPDU_SIZE	16
- #define AVG_PKT_SIZE	1200
- 
-+#define SAMPLE_SWITCH_THR	100
-+
- /* Number of bits for an average sized packet */
- #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
- 
-@@ -59,6 +61,7 @@
- 	[GROUP_IDX(_streams, _sgi, _ht40)] = {				\
- 	.streams = _streams,						\
- 	.shift = _s,							\
-+	.bw = _ht40,							\
- 	.flags =							\
- 		IEEE80211_TX_RC_MCS |					\
- 		(_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |			\
-@@ -95,6 +98,7 @@
- 	[VHT_GROUP_IDX(_streams, _sgi, _bw)] = {			\
- 	.streams = _streams,						\
- 	.shift = _s,							\
-+	.bw = _bw,							\
- 	.flags =							\
- 		IEEE80211_TX_RC_VHT_MCS |				\
- 		(_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |			\
-@@ -527,6 +531,133 @@ minstrel_ht_prob_rate_reduce_streams(str
- 	}
- }
- 
-+static inline int
-+minstrel_get_duration(int index)
-+{
-+	const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
-+	unsigned int duration = group->duration[index % MCS_GROUP_RATES];
-+	return duration << group->shift;
-+}
-+
-+static bool
-+minstrel_ht_probe_group(struct minstrel_ht_sta *mi, const struct mcs_group *tp_group,
-+						int tp_idx, const struct mcs_group *group)
-+{
-+	if (group->bw < tp_group->bw)
-+		return false;
-+
-+	if (group->streams == tp_group->streams)
-+		return true;
-+
-+	if (tp_idx < 4 && group->streams == tp_group->streams - 1)
-+		return true;
-+
-+	return group->streams == tp_group->streams + 1;
-+}
-+
-+static void
-+minstrel_ht_find_probe_rates(struct minstrel_ht_sta *mi, u16 *rates, int *n_rates,
-+			     bool faster_rate)
-+{
-+	const struct mcs_group *group, *tp_group;
-+	int i, g, max_dur;
-+	int tp_idx;
-+
-+	tp_group = &minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES];
-+	tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES;
-+
-+	max_dur = minstrel_get_duration(mi->max_tp_rate[0]);
-+	if (faster_rate)
-+		max_dur -= max_dur / 16;
-+
-+	for (g = 0; g < MINSTREL_GROUPS_NB; g++) {
-+		u16 supported = mi->supported[g];
-+
-+		if (!supported)
-+			continue;
-+
-+		group = &minstrel_mcs_groups[g];
-+		if (!minstrel_ht_probe_group(mi, tp_group, tp_idx, group))
-+			continue;
-+
-+		for (i = 0; supported; supported >>= 1, i++) {
-+			int idx;
-+
-+			if (!(supported & 1))
-+				continue;
-+
-+			if ((group->duration[i] << group->shift) > max_dur)
-+				continue;
-+
-+			idx = g * MCS_GROUP_RATES + i;
-+			if (idx == mi->max_tp_rate[0])
-+				continue;
-+
-+			rates[(*n_rates)++] = idx;
-+			break;
-+		}
-+	}
-+}
-+
-+static void
-+minstrel_ht_rate_sample_switch(struct minstrel_priv *mp,
-+			       struct minstrel_ht_sta *mi)
-+{
-+	struct minstrel_rate_stats *mrs;
-+	u16 rates[MINSTREL_GROUPS_NB];
-+	int n_rates = 0;
-+	int probe_rate = 0;
-+	bool faster_rate;
-+	int i;
-+	u8 random;
-+
-+	/*
-+	 * Use rate switching instead of probing packets for devices with
-+	 * little control over retry fallback behavior
-+	 */
-+	if (mp->hw->max_rates > 1)
-+		return;
-+
-+	/*
-+	 * If the current EWMA prob is >75%, look for a rate that's 6.25%
-+	 * faster than the max tp rate.
-+	 * If that fails, look again for a rate that is at least as fast
-+	 */
-+	mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
-+	faster_rate = mrs->prob_ewma > MINSTREL_FRAC(75, 100);
-+	minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate);
-+	if (!n_rates && faster_rate)
-+		minstrel_ht_find_probe_rates(mi, rates, &n_rates, false);
-+
-+	/* If no suitable rate was found, try to pick the next one in the group */
-+	if (!n_rates) {
-+		int g_idx = mi->max_tp_rate[0] / MCS_GROUP_RATES;
-+		u16 supported = mi->supported[g_idx];
-+
-+		supported >>= mi->max_tp_rate[0] % MCS_GROUP_RATES;
-+		for (i = 0; supported; i++) {
-+			if (!(supported & 1))
-+				continue;
-+
-+			probe_rate = mi->max_tp_rate[0] + i;
-+			goto out;
-+		}
-+
-+		return;
-+	}
-+
-+	i = 0;
-+	if (n_rates > 1) {
-+		random = prandom_u32();
-+		i = random % n_rates;
-+	}
-+	probe_rate = rates[i];
-+
-+out:
-+	mi->sample_rate = probe_rate;
-+	mi->sample_mode = MINSTREL_SAMPLE_ACTIVE;
-+}
-+
- /*
-  * Update rate statistics and select new primary rates
-  *
-@@ -537,7 +668,8 @@ minstrel_ht_prob_rate_reduce_streams(str
-  *    higher throughput rates, even if the probablity is a bit lower
-  */
- static void
--minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
-+minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
-+			 bool sample)
- {
- 	struct minstrel_mcs_group_data *mg;
- 	struct minstrel_rate_stats *mrs;
-@@ -545,6 +677,18 @@ minstrel_ht_update_stats(struct minstrel
- 	u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
- 	u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
- 
-+	mi->sample_mode = MINSTREL_SAMPLE_IDLE;
-+
-+	if (sample) {
-+		mi->total_packets_cur = mi->total_packets -
-+					mi->total_packets_last;
-+		mi->total_packets_last = mi->total_packets;
-+	}
-+	if (!mp->sample_switch)
-+		sample = false;
-+	if (mi->total_packets_cur < SAMPLE_SWITCH_THR && mp->sample_switch != 1)
-+	    sample = false;
-+
- 	if (mi->ampdu_packets > 0) {
- 		if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
- 			mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
-@@ -631,12 +775,16 @@ minstrel_ht_update_stats(struct minstrel
- 	/* try to sample all available rates during each interval */
- 	mi->sample_count *= 8;
- 
-+	if (sample)
-+		minstrel_ht_rate_sample_switch(mp, mi);
-+
- #ifdef CPTCFG_MAC80211_DEBUGFS
- 	/* use fixed index if set */
- 	if (mp->fixed_rate_idx != -1) {
- 		for (i = 0; i < 4; i++)
- 			mi->max_tp_rate[i] = mp->fixed_rate_idx;
- 		mi->max_prob_rate = mp->fixed_rate_idx;
-+		mi->sample_mode = MINSTREL_SAMPLE_IDLE;
- 	}
- #endif
- 
-@@ -740,15 +888,17 @@ minstrel_ht_tx_status(void *priv, struct
- 	struct minstrel_ht_sta_priv *msp = priv_sta;
- 	struct minstrel_ht_sta *mi = &msp->ht;
- 	struct ieee80211_tx_rate *ar = info->status.rates;
--	struct minstrel_rate_stats *rate, *rate2;
-+	struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL;
- 	struct minstrel_priv *mp = priv;
- 	bool last, update = false;
-+	bool sample_status = false;
- 	int i;
- 
- 	if (!msp->is_ht)
- 		return mac80211_minstrel.tx_status_ext(priv, sband,
- 						       &msp->legacy, st);
- 
-+
- 	/* This packet was aggregated but doesn't carry status info */
- 	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
- 	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
-@@ -774,12 +924,17 @@ minstrel_ht_tx_status(void *priv, struct
- 	if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
- 		mi->sample_packets += info->status.ampdu_len;
- 
-+	if (mi->sample_mode != MINSTREL_SAMPLE_IDLE)
-+		rate_sample = minstrel_get_ratestats(mi, mi->sample_rate);
-+
- 	last = !minstrel_ht_txstat_valid(mp, &ar[0]);
- 	for (i = 0; !last; i++) {
- 		last = (i == IEEE80211_TX_MAX_RATES - 1) ||
- 		       !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
- 
- 		rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
-+		if (rate == rate_sample)
-+			sample_status = true;
- 
- 		if (last)
- 			rate->success += info->status.ampdu_ack_len;
-@@ -787,44 +942,60 @@ minstrel_ht_tx_status(void *priv, struct
- 		rate->attempts += ar[i].count * info->status.ampdu_len;
- 	}
- 
--	/*
--	 * check for sudden death of spatial multiplexing,
--	 * downgrade to a lower number of streams if necessary.
--	 */
--	rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
--	if (rate->attempts > 30 &&
--	    MINSTREL_FRAC(rate->success, rate->attempts) <
--	    MINSTREL_FRAC(20, 100)) {
--		minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
-+	switch (mi->sample_mode) {
-+	case MINSTREL_SAMPLE_IDLE:
-+		break;
-+
-+	case MINSTREL_SAMPLE_ACTIVE:
-+		if (!sample_status)
-+			break;
-+
-+		mi->sample_mode = MINSTREL_SAMPLE_PENDING;
- 		update = true;
--	}
-+		break;
-+
-+	case MINSTREL_SAMPLE_PENDING:
-+		if (sample_status)
-+			break;
- 
--	rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
--	if (rate2->attempts > 30 &&
--	    MINSTREL_FRAC(rate2->success, rate2->attempts) <
--	    MINSTREL_FRAC(20, 100)) {
--		minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
- 		update = true;
-+		minstrel_ht_update_stats(mp, mi, false);
-+		break;
-+	}
-+
-+
-+	if (mp->hw->max_rates > 1) {
-+		/*
-+		 * check for sudden death of spatial multiplexing,
-+		 * downgrade to a lower number of streams if necessary.
-+		 */
-+		rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
-+		if (rate->attempts > 30 &&
-+		    MINSTREL_FRAC(rate->success, rate->attempts) <
-+		    MINSTREL_FRAC(20, 100)) {
-+			minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
-+			update = true;
-+		}
-+
-+		rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
-+		if (rate2->attempts > 30 &&
-+		    MINSTREL_FRAC(rate2->success, rate2->attempts) <
-+		    MINSTREL_FRAC(20, 100)) {
-+			minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
-+			update = true;
-+		}
- 	}
- 
- 	if (time_after(jiffies, mi->last_stats_update +
- 				(mp->update_interval / 2 * HZ) / 1000)) {
- 		update = true;
--		minstrel_ht_update_stats(mp, mi);
-+		minstrel_ht_update_stats(mp, mi, true);
- 	}
- 
- 	if (update)
- 		minstrel_ht_update_rates(mp, mi);
- }
- 
--static inline int
--minstrel_get_duration(int index)
--{
--	const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
--	unsigned int duration = group->duration[index % MCS_GROUP_RATES];
--	return duration << group->shift;
--}
--
- static void
- minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
-                          int index)
-@@ -989,14 +1160,18 @@ static void
- minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
- {
- 	struct ieee80211_sta_rates *rates;
-+	u16 first_rate = mi->max_tp_rate[0];
- 	int i = 0;
- 
-+	if (mi->sample_mode == MINSTREL_SAMPLE_ACTIVE)
-+		first_rate = mi->sample_rate;
-+
- 	rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
- 	if (!rates)
- 		return;
- 
- 	/* Start with max_tp_rate[0] */
--	minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
-+	minstrel_ht_set_rate(mp, mi, rates, i++, first_rate);
- 
- 	if (mp->hw->max_rates >= 3) {
- 		/* At least 3 tx rates supported, use max_tp_rate[1] next */
-@@ -1023,6 +1198,11 @@ minstrel_get_sample_rate(struct minstrel
- 	int tp_rate1, tp_rate2;
- 	int sample_idx = 0;
- 
-+	if (mp->hw->max_rates == 1 && mp->sample_switch &&
-+	    (mi->total_packets_cur >= SAMPLE_SWITCH_THR ||
-+	     mp->sample_switch == 1))
-+		return -1;
-+
- 	if (mi->sample_wait > 0) {
- 		mi->sample_wait--;
- 		return -1;
-@@ -1349,7 +1529,7 @@ minstrel_ht_update_caps(void *priv, stru
- 	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);
-+	minstrel_ht_update_stats(mp, mi, true);
- 	minstrel_ht_update_rates(mp, mi);
- 
- 	return;
-@@ -1467,6 +1647,8 @@ minstrel_ht_alloc(struct ieee80211_hw *h
- 	if (!mp)
- 		return NULL;
- 
-+	mp->sample_switch = -1;
-+
- 	/* contention window settings
- 	 * Just an approximation. Using the per-queue values would complicate
- 	 * the calculations and is probably unnecessary */
-@@ -1498,6 +1680,8 @@ minstrel_ht_alloc(struct ieee80211_hw *h
- 	mp->fixed_rate_idx = (u32) -1;
- 	debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
- 			   &mp->fixed_rate_idx);
-+	debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir,
-+			   &mp->sample_switch);
- #endif
- 
- 	minstrel_ht_init_cck_rates(mp);
---- a/net/mac80211/rc80211_minstrel_ht.h
-+++ b/net/mac80211/rc80211_minstrel_ht.h
-@@ -36,6 +36,7 @@ struct mcs_group {
- 	u16 flags;
- 	u8 streams;
- 	u8 shift;
-+	u8 bw;
- 	u16 duration[MCS_GROUP_RATES];
- };
- 
-@@ -53,6 +54,12 @@ struct minstrel_mcs_group_data {
- 	struct minstrel_rate_stats rates[MCS_GROUP_RATES];
- };
- 
-+enum minstrel_sample_mode {
-+	MINSTREL_SAMPLE_IDLE,
-+	MINSTREL_SAMPLE_ACTIVE,
-+	MINSTREL_SAMPLE_PENDING,
-+};
-+
- struct minstrel_ht_sta {
- 	struct ieee80211_sta *sta;
- 
-@@ -74,6 +81,8 @@ struct minstrel_ht_sta {
- 	unsigned int overhead;
- 	unsigned int overhead_rtscts;
- 
-+	unsigned int total_packets_last;
-+	unsigned int total_packets_cur;
- 	unsigned int total_packets;
- 	unsigned int sample_packets;
- 
-@@ -85,6 +94,9 @@ struct minstrel_ht_sta {
- 	u8 sample_count;
- 	u8 sample_slow;
- 
-+	enum minstrel_sample_mode sample_mode;
-+	u16 sample_rate;
-+
- 	/* current MCS group to be sampled */
- 	u8 sample_group;
-