2013-04-22 10:09:59

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v5 1/3] mac80211: improve the rate control API

Allow rate control modules to pass a rate selection table to mac80211
and the driver. This allows drivers to fetch the most recent rate
selection from the sta pointer for already buffered frames. This allows
rate control to respond faster to sudden link changes and it is also a
step towards adding minstrel_ht support to drivers like iwlwifi.

When a driver sets IEEE80211_HW_SUPPORTS_RC_TABLE, mac80211 will not
fill info->control.rates with rates from the rate table (to preserve
explicit overrides by the rate control module). The driver then
explicitly calls ieee80211_get_tx_rates to merge overrides from
info->control.rates with defaults from the sta rate table.

Signed-off-by: Felix Fietkau <[email protected]>
---
include/net/mac80211.h | 66 +++++++++
net/mac80211/ieee80211_i.h | 1 +
net/mac80211/rate.c | 327 +++++++++++++++++++++++++++++++++++++--------
net/mac80211/tx.c | 142 +++++---------------
4 files changed, 369 insertions(+), 167 deletions(-)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 4f693a5..5ceb19f 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -561,6 +561,9 @@ enum mac80211_rate_control_flags {
/* maximum number of rate stages */
#define IEEE80211_TX_MAX_RATES 4

+/* maximum number of rate table entries */
+#define IEEE80211_TX_RATE_TABLE_SIZE 4
+
/**
* struct ieee80211_tx_rate - rate selection/status
*
@@ -657,6 +660,8 @@ struct ieee80211_tx_info {
s8 rts_cts_rate_idx;
u8 use_rts:1;
u8 use_cts_prot:1;
+ u8 short_preamble:1;
+ u8 skip_table:1;
/* 2 bytes free */
};
/* only needed before rate control */
@@ -678,6 +683,8 @@ struct ieee80211_tx_info {
struct {
struct ieee80211_tx_rate driver_rates[
IEEE80211_TX_MAX_RATES];
+ u8 pad[4];
+
void *rate_driver_data[
IEEE80211_TX_INFO_RATE_DRIVER_DATA_SIZE / sizeof(void *)];
};
@@ -1223,6 +1230,24 @@ enum ieee80211_sta_rx_bandwidth {
};

/**
+ * struct ieee80211_sta_rates - station rate selection table
+ *
+ * @rcu_head: RCU head used for freeing the table on update
+ * @rates: transmit rates/flags to be used by default.
+ * Overriding entries per-packet is possible by using cb tx control.
+ */
+struct ieee80211_sta_rates {
+ struct rcu_head rcu_head;
+ struct {
+ u8 idx;
+ u8 count;
+ u8 count_cts;
+ u8 count_rts;
+ u16 flags;
+ } rate[IEEE80211_TX_RATE_TABLE_SIZE];
+};
+
+/**
* struct ieee80211_sta - station table entry
*
* A station table entry represents a station we are possibly
@@ -1249,6 +1274,7 @@ enum ieee80211_sta_rx_bandwidth {
* notifications and capabilities. The value is only valid after
* the station moves to associated state.
* @smps_mode: current SMPS mode (off, static or dynamic)
+ * @tx_rates: rate control selection table
*/
struct ieee80211_sta {
u32 supp_rates[IEEE80211_NUM_BANDS];
@@ -1262,6 +1288,7 @@ struct ieee80211_sta {
u8 rx_nss;
enum ieee80211_sta_rx_bandwidth bandwidth;
enum ieee80211_smps_mode smps_mode;
+ struct ieee80211_sta_rates __rcu *rates;

/* must be last */
u8 drv_priv[0] __aligned(sizeof(void *));
@@ -1417,6 +1444,9 @@ struct ieee80211_tx_control {
* for different virtual interfaces. See the doc section on HW queue
* control for more details.
*
+ * @IEEE80211_HW_SUPPORTS_RC_TABLE: The driver supports using a rate
+ * selection table provided by the rate control algorithm.
+ *
* @IEEE80211_HW_P2P_DEV_ADDR_FOR_INTF: Use the P2P Device address for any
* P2P Interface. This will be honoured even if more than one interface
* is supported.
@@ -1449,6 +1479,7 @@ enum ieee80211_hw_flags {
IEEE80211_HW_SUPPORTS_PER_STA_GTK = 1<<21,
IEEE80211_HW_AP_LINK_PS = 1<<22,
IEEE80211_HW_TX_AMPDU_SETUP_IN_HW = 1<<23,
+ IEEE80211_HW_SUPPORTS_RC_TABLE = 1<<24,
IEEE80211_HW_P2P_DEV_ADDR_FOR_INTF = 1<<25,
IEEE80211_HW_TIMING_BEACON_ONLY = 1<<26,
};
@@ -3135,6 +3166,25 @@ void ieee80211_sta_set_buffered(struct ieee80211_sta *sta,
u8 tid, bool buffered);

/**
+ * ieee80211_get_tx_rates - get the selected transmit rates for a packet
+ *
+ * Call this function in a driver with per-packet rate selection support
+ * to combine the rate info in the packet tx info with the most recent
+ * rate selection table for the station entry.
+ *
+ * @vif: &struct ieee80211_vif pointer from the add_interface callback.
+ * @sta: the receiver station to which this packet is sent.
+ * @skb: the frame to be transmitted.
+ * @dest: buffer for extracted rate/retry information
+ * @max_rates: maximum number of rates to fetch
+ */
+void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
+ struct ieee80211_sta *sta,
+ struct sk_buff *skb,
+ struct ieee80211_tx_rate *dest,
+ int max_rates);
+
+/**
* ieee80211_tx_status - transmit status callback
*
* Call this function for all transmitted frames after they have been
@@ -4210,6 +4260,22 @@ bool rate_usable_index_exists(struct ieee80211_supported_band *sband,
return false;
}

+/**
+ * rate_control_set_rates - pass the sta rate selection to mac80211/driver
+ *
+ * When not doing a rate control probe to test rates, rate control should pass
+ * its rate selection to mac80211. If the driver supports receiving a station
+ * rate table, it will use it to ensure that frames are always sent based on
+ * the most recent rate control module decision.
+ *
+ * @hw: pointer as obtained from ieee80211_alloc_hw()
+ * @pubsta: &struct ieee80211_sta pointer to the target destination.
+ * @rates: new tx rate set to be used for this station.
+ */
+int rate_control_set_rates(struct ieee80211_hw *hw,
+ struct ieee80211_sta *pubsta,
+ struct ieee80211_sta_rates *rates);
+
int ieee80211_rate_control_register(struct rate_control_ops *ops);
void ieee80211_rate_control_unregister(struct rate_control_ops *ops);

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index af8410e..158e6eb 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -156,6 +156,7 @@ struct ieee80211_tx_data {
struct ieee80211_sub_if_data *sdata;
struct sta_info *sta;
struct ieee80211_key *key;
+ struct ieee80211_tx_rate rate;

unsigned int flags;
};
diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 5d545dd..0d51877 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -252,6 +252,25 @@ rate_lowest_non_cck_index(struct ieee80211_supported_band *sband,
return 0;
}

+static void __rate_control_send_low(struct ieee80211_hw *hw,
+ struct ieee80211_supported_band *sband,
+ struct ieee80211_sta *sta,
+ struct ieee80211_tx_info *info)
+{
+ if ((sband->band != IEEE80211_BAND_2GHZ) ||
+ !(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
+ info->control.rates[0].idx = rate_lowest_index(sband, sta);
+ else
+ info->control.rates[0].idx =
+ rate_lowest_non_cck_index(sband, sta);
+
+ info->control.rates[0].count =
+ (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
+ 1 : hw->max_rate_tries;
+
+ info->control.skip_table = 1;
+}
+

bool rate_control_send_low(struct ieee80211_sta *sta,
void *priv_sta,
@@ -262,16 +281,8 @@ bool rate_control_send_low(struct ieee80211_sta *sta,
int mcast_rate;

if (!sta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
- if ((sband->band != IEEE80211_BAND_2GHZ) ||
- !(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
- info->control.rates[0].idx =
- rate_lowest_index(txrc->sband, sta);
- else
- info->control.rates[0].idx =
- rate_lowest_non_cck_index(txrc->sband, sta);
- info->control.rates[0].count =
- (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
- 1 : txrc->hw->max_rate_tries;
+ __rate_control_send_low(txrc->hw, sband, sta, info);
+
if (!sta && txrc->bss) {
mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
if (mcast_rate > 0) {
@@ -355,7 +366,8 @@ static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,


static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
- struct ieee80211_tx_rate_control *txrc,
+ struct ieee80211_supported_band *sband,
+ enum nl80211_chan_width chan_width,
u32 mask,
u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
{
@@ -375,27 +387,17 @@ static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
alt_rate.count = rate->count;
if (rate_idx_match_legacy_mask(&alt_rate,
- txrc->sband->n_bitrates,
- mask)) {
+ sband->n_bitrates, mask)) {
*rate = alt_rate;
return;
}
} else {
- struct sk_buff *skb = txrc->skb;
- struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
- __le16 fc;
-
/* handle legacy rates */
- if (rate_idx_match_legacy_mask(rate, txrc->sband->n_bitrates,
- mask))
+ if (rate_idx_match_legacy_mask(rate, sband->n_bitrates, mask))
return;

/* if HT BSS, and we handle a data frame, also try HT rates */
- if (txrc->bss_conf->chandef.width == NL80211_CHAN_WIDTH_20_NOHT)
- return;
-
- fc = hdr->frame_control;
- if (!ieee80211_is_data(fc))
+ if (chan_width == NL80211_CHAN_WIDTH_20_NOHT)
return;

alt_rate.idx = 0;
@@ -408,7 +410,7 @@ static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,

alt_rate.flags |= IEEE80211_TX_RC_MCS;

- if (txrc->bss_conf->chandef.width == NL80211_CHAN_WIDTH_40)
+ if (chan_width == NL80211_CHAN_WIDTH_40)
alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;

if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
@@ -426,6 +428,228 @@ static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
*/
}

+static void rate_fixup_ratelist(struct ieee80211_vif *vif,
+ struct ieee80211_supported_band *sband,
+ struct ieee80211_tx_info *info,
+ struct ieee80211_tx_rate *rates,
+ int max_rates)
+{
+ struct ieee80211_rate *rate;
+ bool inval = false;
+ int i;
+
+ /*
+ * Set up the RTS/CTS rate as the fastest basic rate
+ * that is not faster than the data rate unless there
+ * is no basic rate slower than the data rate, in which
+ * case we pick the slowest basic rate
+ *
+ * XXX: Should this check all retry rates?
+ */
+ if (!(rates[0].flags & IEEE80211_TX_RC_MCS)) {
+ u32 basic_rates = vif->bss_conf.basic_rates;
+ s8 baserate = basic_rates ? ffs(basic_rates - 1) : 0;
+
+ rate = &sband->bitrates[rates[0].idx];
+
+ for (i = 0; i < sband->n_bitrates; i++) {
+ /* must be a basic rate */
+ if (!(basic_rates & BIT(i)))
+ continue;
+ /* must not be faster than the data rate */
+ if (sband->bitrates[i].bitrate > rate->bitrate)
+ continue;
+ /* maximum */
+ if (sband->bitrates[baserate].bitrate <
+ sband->bitrates[i].bitrate)
+ baserate = i;
+ }
+
+ info->control.rts_cts_rate_idx = baserate;
+ }
+
+ for (i = 0; i < max_rates; i++) {
+ /*
+ * make sure there's no valid rate following
+ * an invalid one, just in case drivers don't
+ * take the API seriously to stop at -1.
+ */
+ if (inval) {
+ rates[i].idx = -1;
+ continue;
+ }
+ if (rates[i].idx < 0) {
+ inval = true;
+ continue;
+ }
+
+ /*
+ * For now assume MCS is already set up correctly, this
+ * needs to be fixed.
+ */
+ if (rates[i].flags & IEEE80211_TX_RC_MCS) {
+ WARN_ON(rates[i].idx > 76);
+
+ if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
+ info->control.use_cts_prot)
+ rates[i].flags |=
+ IEEE80211_TX_RC_USE_CTS_PROTECT;
+ continue;
+ }
+
+ if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
+ WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
+ continue;
+ }
+
+ /* set up RTS protection if desired */
+ if (info->control.use_rts) {
+ rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
+ info->control.use_cts_prot = false;
+ }
+
+ /* RC is busted */
+ if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
+ rates[i].idx = -1;
+ continue;
+ }
+
+ rate = &sband->bitrates[rates[i].idx];
+
+ /* set up short preamble */
+ if (info->control.short_preamble &&
+ rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
+ rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
+
+ /* set up G protection */
+ if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
+ info->control.use_cts_prot &&
+ rate->flags & IEEE80211_RATE_ERP_G)
+ rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
+ }
+}
+
+
+static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
+ struct ieee80211_tx_info *info,
+ struct ieee80211_tx_rate *rates,
+ int max_rates)
+{
+ struct ieee80211_sta_rates *ratetbl = NULL;
+ int i;
+
+ if (sta && !info->control.skip_table)
+ ratetbl = rcu_dereference(sta->rates);
+
+ /* Fill remaining rate slots with data from the sta rate table. */
+ max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
+ for (i = 0; i < max_rates; i++) {
+ if (i < ARRAY_SIZE(info->control.rates) &&
+ info->control.rates[i].idx >= 0 &&
+ info->control.rates[i].count) {
+ if (rates != info->control.rates)
+ rates[i] = info->control.rates[i];
+ } else if (ratetbl) {
+ rates[i].idx = ratetbl->rate[i].idx;
+ rates[i].flags = ratetbl->rate[i].flags;
+ if (info->control.use_rts)
+ rates[i].count = ratetbl->rate[i].count_rts;
+ else if (info->control.use_cts_prot)
+ rates[i].count = ratetbl->rate[i].count_cts;
+ else
+ rates[i].count = ratetbl->rate[i].count;
+ } else {
+ rates[i].idx = -1;
+ rates[i].count = 0;
+ }
+
+ if (rates[i].idx < 0 || !rates[i].count)
+ break;
+ }
+}
+
+static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_sta *sta,
+ struct ieee80211_supported_band *sband,
+ struct ieee80211_tx_info *info,
+ struct ieee80211_tx_rate *rates,
+ int max_rates)
+{
+ enum nl80211_chan_width chan_width;
+ u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
+ bool has_mcs_mask;
+ u32 mask;
+ int i;
+
+ /*
+ * Try to enforce the rateidx mask the user wanted. skip this if the
+ * default mask (allow all rates) is used to save some processing for
+ * the common case.
+ */
+ mask = sdata->rc_rateidx_mask[info->band];
+ has_mcs_mask = sdata->rc_has_mcs_mask[info->band];
+ if (mask == (1 << sband->n_bitrates) - 1 && !has_mcs_mask)
+ return;
+
+ if (has_mcs_mask)
+ memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
+ sizeof(mcs_mask));
+ else
+ memset(mcs_mask, 0xff, sizeof(mcs_mask));
+
+ if (sta) {
+ /* Filter out rates that the STA does not support */
+ mask &= sta->supp_rates[info->band];
+ for (i = 0; i < sizeof(mcs_mask); i++)
+ mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
+ }
+
+ /*
+ * Make sure the rate index selected for each TX rate is
+ * included in the configured mask and change the rate indexes
+ * if needed.
+ */
+ chan_width = sdata->vif.bss_conf.chandef.width;
+ for (i = 0; i < max_rates; i++) {
+ /* Skip invalid rates */
+ if (rates[i].idx < 0)
+ break;
+
+ rate_idx_match_mask(&rates[i], sband, mask, chan_width,
+ mcs_mask);
+ }
+}
+
+void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
+ struct ieee80211_sta *sta,
+ struct sk_buff *skb,
+ struct ieee80211_tx_rate *dest,
+ int max_rates)
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+ struct ieee80211_supported_band *sband;
+
+ rate_control_fill_sta_table(sta, info, dest, max_rates);
+
+ if (!vif)
+ return;
+
+ sdata = vif_to_sdata(vif);
+ sband = sdata->local->hw.wiphy->bands[info->band];
+
+ if (ieee80211_is_data(hdr->frame_control))
+ rate_control_apply_mask(sdata, sta, sband, info, dest, max_rates);
+
+ if (dest[0].idx < 0)
+ __rate_control_send_low(&sdata->local->hw, sband, sta, info);
+
+ if (sta)
+ rate_fixup_ratelist(vif, sband, info, dest, max_rates);
+}
+EXPORT_SYMBOL(ieee80211_get_tx_rates);
+
void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta,
struct ieee80211_tx_rate_control *txrc)
@@ -435,8 +659,6 @@ void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
struct ieee80211_sta *ista = NULL;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
int i;
- u32 mask;
- u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];

if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
ista = &sta->sta;
@@ -454,40 +676,27 @@ void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,

ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);

- /*
- * Try to enforce the rateidx mask the user wanted. skip this if the
- * default mask (allow all rates) is used to save some processing for
- * the common case.
- */
- mask = sdata->rc_rateidx_mask[info->band];
- if (mask != (1 << txrc->sband->n_bitrates) - 1 || txrc->rate_idx_mcs_mask) {
- if (txrc->rate_idx_mcs_mask)
- memcpy(mcs_mask, txrc->rate_idx_mcs_mask, sizeof(mcs_mask));
- else
- memset(mcs_mask, 0xff, sizeof(mcs_mask));
-
- if (sta) {
- /* Filter out rates that the STA does not support */
- mask &= sta->sta.supp_rates[info->band];
- for (i = 0; i < sizeof(mcs_mask); i++)
- mcs_mask[i] &= sta->sta.ht_cap.mcs.rx_mask[i];
- }
- /*
- * Make sure the rate index selected for each TX rate is
- * included in the configured mask and change the rate indexes
- * if needed.
- */
- for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
- /* Skip invalid rates */
- if (info->control.rates[i].idx < 0)
- break;
- rate_idx_match_mask(&info->control.rates[i], txrc,
- mask, mcs_mask);
- }
- }
+ if (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_RC_TABLE)
+ return;
+
+ ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
+ info->control.rates,
+ ARRAY_SIZE(info->control.rates));
+}

- BUG_ON(info->control.rates[0].idx < 0);
+int rate_control_set_rates(struct ieee80211_hw *hw,
+ struct ieee80211_sta *pubsta,
+ struct ieee80211_sta_rates *rates)
+{
+ struct ieee80211_sta_rates *old = rcu_dereference(pubsta->rates);
+
+ rcu_assign_pointer(pubsta->rates, rates);
+ if (old)
+ kfree_rcu(old, rcu_head);
+
+ return 0;
}
+EXPORT_SYMBOL(rate_control_set_rates);

int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
const char *name)
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 6ca857f..4a5fbf8 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -48,15 +48,15 @@ static __le16 ieee80211_duration(struct ieee80211_tx_data *tx,
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

/* assume HW handles this */
- if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
+ if (tx->rate.flags & IEEE80211_TX_RC_MCS)
return 0;

/* uh huh? */
- if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
+ if (WARN_ON_ONCE(tx->rate.idx < 0))
return 0;

sband = local->hw.wiphy->bands[info->band];
- txrate = &sband->bitrates[info->control.rates[0].idx];
+ txrate = &sband->bitrates[tx->rate.idx];

erp = txrate->flags & IEEE80211_RATE_ERP_G;

@@ -617,11 +617,9 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
struct ieee80211_hdr *hdr = (void *)tx->skb->data;
struct ieee80211_supported_band *sband;
- struct ieee80211_rate *rate;
- int i;
u32 len;
- bool inval = false, rts = false, short_preamble = false;
struct ieee80211_tx_rate_control txrc;
+ struct ieee80211_sta_rates *ratetbl = NULL;
bool assoc = false;

memset(&txrc, 0, sizeof(txrc));
@@ -653,10 +651,10 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)

/* set up RTS protection if desired */
if (len > tx->local->hw.wiphy->rts_threshold) {
- txrc.rts = rts = true;
+ txrc.rts = true;
}

- info->control.use_rts = rts;
+ info->control.use_rts = txrc.rts;
info->control.use_cts_prot = tx->sdata->vif.bss_conf.use_cts_prot;

/*
@@ -668,7 +666,9 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
if (tx->sdata->vif.bss_conf.use_short_preamble &&
(ieee80211_is_data(hdr->frame_control) ||
(tx->sta && test_sta_flag(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
- txrc.short_preamble = short_preamble = true;
+ txrc.short_preamble = true;
+
+ info->control.short_preamble = txrc.short_preamble;

if (tx->sta)
assoc = test_sta_flag(tx->sta, WLAN_STA_ASSOC);
@@ -692,16 +692,38 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
*/
rate_control_get_rate(tx->sdata, tx->sta, &txrc);

- if (unlikely(info->control.rates[0].idx < 0))
- return TX_DROP;
+ if (tx->sta && !info->control.skip_table)
+ ratetbl = rcu_dereference(tx->sta->sta.rates);
+
+ if (unlikely(info->control.rates[0].idx < 0)) {
+ if (ratetbl) {
+ struct ieee80211_tx_rate rate = {
+ .idx = ratetbl->rate[0].idx,
+ .flags = ratetbl->rate[0].flags,
+ .count = ratetbl->rate[0].count
+ };
+
+ if (ratetbl->rate[0].idx < 0)
+ return TX_DROP;
+
+ tx->rate = rate;
+ } else {
+ return TX_DROP;
+ }
+ } else {
+ tx->rate = info->control.rates[0];
+ }

if (txrc.reported_rate.idx < 0) {
- txrc.reported_rate = info->control.rates[0];
+ txrc.reported_rate = tx->rate;
if (tx->sta && ieee80211_is_data(hdr->frame_control))
tx->sta->last_tx_rate = txrc.reported_rate;
} else if (tx->sta)
tx->sta->last_tx_rate = txrc.reported_rate;

+ if (ratetbl)
+ return TX_CONTINUE;
+
if (unlikely(!info->control.rates[0].count))
info->control.rates[0].count = 1;

@@ -709,102 +731,6 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
(info->flags & IEEE80211_TX_CTL_NO_ACK)))
info->control.rates[0].count = 1;

- if (is_multicast_ether_addr(hdr->addr1)) {
- /*
- * XXX: verify the rate is in the basic rateset
- */
- return TX_CONTINUE;
- }
-
- /*
- * Set up the RTS/CTS rate as the fastest basic rate
- * that is not faster than the data rate unless there
- * is no basic rate slower than the data rate, in which
- * case we pick the slowest basic rate
- *
- * XXX: Should this check all retry rates?
- */
- if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
- u32 basic_rates = tx->sdata->vif.bss_conf.basic_rates;
- s8 baserate = basic_rates ? ffs(basic_rates - 1) : 0;
-
- rate = &sband->bitrates[info->control.rates[0].idx];
-
- for (i = 0; i < sband->n_bitrates; i++) {
- /* must be a basic rate */
- if (!(basic_rates & BIT(i)))
- continue;
- /* must not be faster than the data rate */
- if (sband->bitrates[i].bitrate > rate->bitrate)
- continue;
- /* maximum */
- if (sband->bitrates[baserate].bitrate <
- sband->bitrates[i].bitrate)
- baserate = i;
- }
-
- info->control.rts_cts_rate_idx = baserate;
- }
-
- for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
- struct ieee80211_tx_rate *rc_rate = &info->control.rates[i];
-
- /*
- * make sure there's no valid rate following
- * an invalid one, just in case drivers don't
- * take the API seriously to stop at -1.
- */
- if (inval) {
- rc_rate->idx = -1;
- continue;
- }
- if (rc_rate->idx < 0) {
- inval = true;
- continue;
- }
-
- /*
- * For now assume MCS is already set up correctly, this
- * needs to be fixed.
- */
- if (rc_rate->flags & IEEE80211_TX_RC_MCS) {
- WARN_ON(rc_rate->idx > 76);
-
- if (!(rc_rate->flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
- tx->sdata->vif.bss_conf.use_cts_prot)
- rc_rate->flags |=
- IEEE80211_TX_RC_USE_CTS_PROTECT;
- continue;
- }
-
- if (rc_rate->flags & IEEE80211_TX_RC_VHT_MCS) {
- WARN_ON(ieee80211_rate_get_vht_mcs(rc_rate) > 9);
- continue;
- }
-
- /* set up RTS protection if desired */
- if (rts)
- rc_rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
-
- /* RC is busted */
- if (WARN_ON_ONCE(rc_rate->idx >= sband->n_bitrates)) {
- rc_rate->idx = -1;
- continue;
- }
-
- rate = &sband->bitrates[rc_rate->idx];
-
- /* set up short preamble */
- if (short_preamble &&
- rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
- rc_rate->flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
-
- /* set up G protection */
- if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
- rate->flags & IEEE80211_RATE_ERP_G)
- rc_rate->flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
- }
-
return TX_CONTINUE;
}

--
1.8.0.2



2013-04-22 10:09:58

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v5 2/3] mac80211/minstrel_ht: use the new rate control API

Pass the rate selection table to mac80211 from minstrel_ht_update_stats.
Only rates for sample attempts are set in info->control.rates.

Signed-off-by: Felix Fietkau <[email protected]>
---
net/mac80211/rc80211_minstrel_ht.c | 150 ++++++++++++++++++++-----------------
net/mac80211/rc80211_minstrel_ht.h | 2 +
2 files changed, 84 insertions(+), 68 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index a8e979e..5b2d301 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -126,6 +126,9 @@ const struct mcs_group minstrel_mcs_groups[] = {

static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES];

+static void
+minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
+
/*
* Look up an MCS group index based on mac80211 rate information
*/
@@ -465,7 +468,7 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
struct ieee80211_tx_rate *ar = info->status.rates;
struct minstrel_rate_stats *rate, *rate2;
struct minstrel_priv *mp = priv;
- bool last;
+ bool last, update = false;
int i;

if (!msp->is_ht)
@@ -514,21 +517,29 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
rate = minstrel_get_ratestats(mi, mi->max_tp_rate);
if (rate->attempts > 30 &&
MINSTREL_FRAC(rate->success, rate->attempts) <
- MINSTREL_FRAC(20, 100))
+ MINSTREL_FRAC(20, 100)) {
minstrel_downgrade_rate(mi, &mi->max_tp_rate, true);
+ update = true;
+ }

rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
if (rate2->attempts > 30 &&
MINSTREL_FRAC(rate2->success, rate2->attempts) <
- MINSTREL_FRAC(20, 100))
+ MINSTREL_FRAC(20, 100)) {
minstrel_downgrade_rate(mi, &mi->max_tp_rate2, false);
+ update = true;
+ }

if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
+ update = true;
minstrel_ht_update_stats(mp, mi);
if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
minstrel_aggr_check(sta, skb);
}
+
+ if (update)
+ minstrel_ht_update_rates(mp, mi);
}

static void
@@ -592,36 +603,71 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,

static void
minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
- struct ieee80211_tx_rate *rate, int index,
- bool sample, bool rtscts)
+ struct ieee80211_sta_rates *ratetbl, int offset, int index)
{
const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
struct minstrel_rate_stats *mr;
+ u8 idx;
+ u16 flags;

mr = minstrel_get_ratestats(mi, index);
if (!mr->retry_updated)
minstrel_calc_retransmit(mp, mi, index);

- if (sample)
- rate->count = 1;
- else if (mr->probability < MINSTREL_FRAC(20, 100))
- rate->count = 2;
- else if (rtscts)
- rate->count = mr->retry_count_rtscts;
- else
- rate->count = mr->retry_count;
-
- rate->flags = 0;
- if (rtscts)
- rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
+ if (mr->probability < MINSTREL_FRAC(20, 100) || !mr->retry_count) {
+ ratetbl->rate[offset].count = 2;
+ ratetbl->rate[offset].count_rts = 2;
+ ratetbl->rate[offset].count_cts = 2;
+ } else {
+ ratetbl->rate[offset].count = mr->retry_count;
+ ratetbl->rate[offset].count_cts = mr->retry_count;
+ ratetbl->rate[offset].count_rts = mr->retry_count_rtscts;
+ }

if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
- rate->idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
+ idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
+ flags = 0;
+ } else {
+ idx = index % MCS_GROUP_RATES +
+ (group->streams - 1) * MCS_GROUP_RATES;
+ flags = IEEE80211_TX_RC_MCS | group->flags;
+ }
+
+ if (offset > 0) {
+ ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
+ flags |= IEEE80211_TX_RC_USE_RTS_CTS;
+ }
+
+ ratetbl->rate[offset].idx = idx;
+ ratetbl->rate[offset].flags = flags;
+}
+
+static void
+minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
+{
+ struct ieee80211_sta_rates *rates;
+ int i = 0;
+
+ rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
+ if (!rates)
return;
+
+ /* Start with max_tp_rate */
+ minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate);
+
+ if (mp->hw->max_rates >= 3) {
+ /* At least 3 tx rates supported, use max_tp_rate2 next */
+ minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate2);
+ }
+
+ if (mp->hw->max_rates >= 2) {
+ /*
+ * At least 2 tx rates supported, use max_prob_rate next */
+ minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
}

- rate->flags |= IEEE80211_TX_RC_MCS | group->flags;
- rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES;
+ rates->rate[i].idx = -1;
+ rate_control_set_rates(mp->hw, mi->sta, rates);
}

static inline int
@@ -711,13 +757,13 @@ static void
minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
struct ieee80211_tx_rate_control *txrc)
{
+ const struct mcs_group *sample_group;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
- struct ieee80211_tx_rate *ar = info->status.rates;
+ struct ieee80211_tx_rate *rate = &info->status.rates[0];
struct minstrel_ht_sta_priv *msp = priv_sta;
struct minstrel_ht_sta *mi = &msp->ht;
struct minstrel_priv *mp = priv;
int sample_idx;
- bool sample = false;

if (rate_control_send_low(sta, priv_sta, txrc))
return;
@@ -745,51 +791,6 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
}
#endif

- if (sample_idx >= 0) {
- sample = true;
- minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,
- true, false);
- info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
- } else {
- minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
- false, false);
- }
-
- if (mp->hw->max_rates >= 3) {
- /*
- * At least 3 tx rates supported, use
- * sample_rate -> max_tp_rate -> max_prob_rate for sampling and
- * max_tp_rate -> max_tp_rate2 -> max_prob_rate by default.
- */
- if (sample_idx >= 0)
- minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate,
- false, false);
- else
- minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate2,
- false, true);
-
- minstrel_ht_set_rate(mp, mi, &ar[2], mi->max_prob_rate,
- false, !sample);
-
- ar[3].count = 0;
- ar[3].idx = -1;
- } else if (mp->hw->max_rates == 2) {
- /*
- * Only 2 tx rates supported, use
- * sample_rate -> max_prob_rate for sampling and
- * max_tp_rate -> max_prob_rate by default.
- */
- minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_prob_rate,
- false, !sample);
-
- ar[2].count = 0;
- ar[2].idx = -1;
- } else {
- /* Not using MRR, only use the first rate */
- ar[1].count = 0;
- ar[1].idx = -1;
- }
-
mi->total_packets++;

/* wraparound */
@@ -797,6 +798,16 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
mi->total_packets = 0;
mi->sample_packets = 0;
}
+
+ if (sample_idx < 0)
+ return;
+
+ sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
+ info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
+ rate->idx = sample_idx % MCS_GROUP_RATES +
+ (sample_group->streams - 1) * MCS_GROUP_RATES;
+ rate->flags = IEEE80211_TX_RC_MCS | sample_group->flags;
+ rate->count = 1;
}

static void
@@ -846,6 +857,8 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,

msp->is_ht = true;
memset(mi, 0, sizeof(*mi));
+
+ mi->sta = sta;
mi->stats_update = jiffies;

ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1);
@@ -907,8 +920,9 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
if (!n_supported)
goto use_legacy;

- /* init {mi,mi->groups[*]}->{max_tp_rate,max_tp_rate2,max_prob_rate} */
+ /* create an initial rate table with the lowest supported rates */
minstrel_ht_update_stats(mp, mi);
+ minstrel_ht_update_rates(mp, mi);

return;

diff --git a/net/mac80211/rc80211_minstrel_ht.h b/net/mac80211/rc80211_minstrel_ht.h
index 9b16e9d..d655586 100644
--- a/net/mac80211/rc80211_minstrel_ht.h
+++ b/net/mac80211/rc80211_minstrel_ht.h
@@ -65,6 +65,8 @@ struct minstrel_mcs_group_data {
};

struct minstrel_ht_sta {
+ struct ieee80211_sta *sta;
+
/* ampdu length (average, per sampling interval) */
unsigned int ampdu_len;
unsigned int ampdu_packets;
--
1.8.0.2


2013-04-22 14:16:09

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v5 1/3] mac80211: improve the rate control API

On Mon, 2013-04-22 at 16:08 +0200, Felix Fietkau wrote:

> >> + if (ratetbl->rate[0].idx < 0)
> >> + return TX_DROP;
> >
> > This can't happen, idx is unsigned. Did you intend idx to be signed?

> Right, shouldn't the compiler warn about this? Will send v6.

I don't think the compiler does (probably would be too many false
positives), but smatch did :-)

johannes


2013-04-22 10:26:09

by Karl Beldan

[permalink] [raw]
Subject: Re: [PATCH v5 1/3] mac80211: improve the rate control API

On Mon, Apr 22, 2013 at 12:09:51PM +0200, Felix Fietkau wrote:
> Allow rate control modules to pass a rate selection table to mac80211
> and the driver. This allows drivers to fetch the most recent rate
> selection from the sta pointer for already buffered frames. This allows
> rate control to respond faster to sudden link changes and it is also a
> step towards adding minstrel_ht support to drivers like iwlwifi.
>
> When a driver sets IEEE80211_HW_SUPPORTS_RC_TABLE, mac80211 will not
> fill info->control.rates with rates from the rate table (to preserve
> explicit overrides by the rate control module). The driver then
> explicitly calls ieee80211_get_tx_rates to merge overrides from
> info->control.rates with defaults from the sta rate table.
>
> Signed-off-by: Felix Fietkau <[email protected]>
> ---
Looks ok to me.

Karl

2013-04-22 14:08:23

by Felix Fietkau

[permalink] [raw]
Subject: Re: [PATCH v5 1/3] mac80211: improve the rate control API

On 2013-04-22 3:52 PM, Johannes Berg wrote:
> On Mon, 2013-04-22 at 12:09 +0200, Felix Fietkau wrote:
>
>> @@ -692,16 +692,38 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
>> */
>> rate_control_get_rate(tx->sdata, tx->sta, &txrc);
>>
>> - if (unlikely(info->control.rates[0].idx < 0))
>> - return TX_DROP;
>> + if (tx->sta && !info->control.skip_table)
>> + ratetbl = rcu_dereference(tx->sta->sta.rates);
>> +
>> + if (unlikely(info->control.rates[0].idx < 0)) {
>> + if (ratetbl) {
>> + struct ieee80211_tx_rate rate = {
>> + .idx = ratetbl->rate[0].idx,
>> + .flags = ratetbl->rate[0].flags,
>> + .count = ratetbl->rate[0].count
>> + };
>> +
>> + if (ratetbl->rate[0].idx < 0)
>> + return TX_DROP;
>
> This can't happen, idx is unsigned. Did you intend idx to be signed?
Right, shouldn't the compiler warn about this? Will send v6.

- Felix


2013-04-22 13:52:53

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v5 1/3] mac80211: improve the rate control API

On Mon, 2013-04-22 at 12:09 +0200, Felix Fietkau wrote:

> @@ -692,16 +692,38 @@ ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
> */
> rate_control_get_rate(tx->sdata, tx->sta, &txrc);
>
> - if (unlikely(info->control.rates[0].idx < 0))
> - return TX_DROP;
> + if (tx->sta && !info->control.skip_table)
> + ratetbl = rcu_dereference(tx->sta->sta.rates);
> +
> + if (unlikely(info->control.rates[0].idx < 0)) {
> + if (ratetbl) {
> + struct ieee80211_tx_rate rate = {
> + .idx = ratetbl->rate[0].idx,
> + .flags = ratetbl->rate[0].flags,
> + .count = ratetbl->rate[0].count
> + };
> +
> + if (ratetbl->rate[0].idx < 0)
> + return TX_DROP;

This can't happen, idx is unsigned. Did you intend idx to be signed?

johannes


2013-04-22 10:09:58

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v5 3/3] mac80211/minstrel: use the new rate control API

Pass the rate selection table to mac80211 from minstrel_update_stats.
Only rates for sample attempts are set in info->control.rates, with deferred
sampling, only the second slot gets changed.

Signed-off-by: Felix Fietkau <[email protected]>
---
net/mac80211/rc80211_minstrel.c | 200 ++++++++++++++++++++++------------------
net/mac80211/rc80211_minstrel.h | 2 +
2 files changed, 111 insertions(+), 91 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index eda290f..ac7ef54 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -84,6 +84,50 @@ minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list)
}

static void
+minstrel_set_rate(struct minstrel_sta_info *mi, struct ieee80211_sta_rates *ratetbl,
+ int offset, int idx)
+{
+ struct minstrel_rate *r = &mi->r[idx];
+
+ ratetbl->rate[offset].idx = r->rix;
+ ratetbl->rate[offset].count = r->adjusted_retry_count;
+ ratetbl->rate[offset].count_cts = r->retry_count_cts;
+ ratetbl->rate[offset].count_rts = r->retry_count_rtscts;
+}
+
+static void
+minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
+{
+ struct ieee80211_sta_rates *ratetbl;
+ int i = 0;
+
+ ratetbl = kzalloc(sizeof(*ratetbl), GFP_ATOMIC);
+ if (!ratetbl)
+ return;
+
+ /* Start with max_tp_rate */
+ minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[0]);
+
+ if (mp->hw->max_rates >= 3) {
+ /* At least 3 tx rates supported, use max_tp_rate2 next */
+ minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[1]);
+ }
+
+ if (mp->hw->max_rates >= 2) {
+ /* At least 2 tx rates supported, use max_prob_rate next */
+ minstrel_set_rate(mi, ratetbl, i++, mi->max_prob_rate);
+ }
+
+ /* Use lowest rate last */
+ ratetbl->rate[i].idx = mi->lowest_rix;
+ ratetbl->rate[i].count = mp->max_retry;
+ ratetbl->rate[i].count_cts = mp->max_retry;
+ ratetbl->rate[i].count_rts = mp->max_retry;
+
+ rate_control_set_rates(mp->hw, mi->sta, ratetbl);
+}
+
+static void
minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
{
u8 tmp_tp_rate[MAX_THR_RATES];
@@ -161,6 +205,8 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)

/* Reset update timer */
mi->stats_update = jiffies;
+
+ minstrel_update_rates(mp, mi);
}

static void
@@ -240,13 +286,12 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct minstrel_sta_info *mi = priv_sta;
struct minstrel_priv *mp = priv;
- struct ieee80211_tx_rate *ar = info->control.rates;
- unsigned int ndx, sample_ndx = 0;
+ struct ieee80211_tx_rate *rate = &info->control.rates[0];
+ struct minstrel_rate *msr, *mr;
+ unsigned int ndx;
bool mrr_capable;
- bool indirect_rate_sampling = false;
- bool rate_sampling = false;
- int i, delta;
- int mrr_ndx[3];
+ bool prev_sample = mi->prev_sample;
+ int delta;
int sampling_ratio;

/* management/no-ack frames do not use rate control */
@@ -262,107 +307,75 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
else
sampling_ratio = mp->lookaround_rate;

- /* init rateindex [ndx] with max throughput rate */
- ndx = mi->max_tp_rate[0];
-
/* increase sum packet counter */
mi->packet_count++;

delta = (mi->packet_count * sampling_ratio / 100) -
(mi->sample_count + mi->sample_deferred / 2);

- /* delta > 0: sampling required */
- if ((delta > 0) && (mrr_capable || !mi->prev_sample)) {
- struct minstrel_rate *msr;
- if (mi->packet_count >= 10000) {
- mi->sample_deferred = 0;
- mi->sample_count = 0;
- mi->packet_count = 0;
- } else if (delta > mi->n_rates * 2) {
- /* With multi-rate retry, not every planned sample
- * attempt actually gets used, due to the way the retry
- * chain is set up - [max_tp,sample,prob,lowest] for
- * sample_rate < max_tp.
- *
- * If there's too much sampling backlog and the link
- * starts getting worse, minstrel would start bursting
- * out lots of sampling frames, which would result
- * in a large throughput loss. */
- mi->sample_count += (delta - mi->n_rates * 2);
- }
+ /* delta < 0: no sampling required */
+ mi->prev_sample = false;
+ if (delta < 0 || (!mrr_capable && prev_sample))
+ return;

- /* get next random rate sample */
- sample_ndx = minstrel_get_next_sample(mi);
- msr = &mi->r[sample_ndx];
- rate_sampling = true;
-
- /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage)
- * rate sampling method should be used.
- * Respect such rates that are not sampled for 20 interations.
- */
- if (mrr_capable &&
- msr->perfect_tx_time > mi->r[ndx].perfect_tx_time &&
- msr->sample_skipped < 20)
- indirect_rate_sampling = true;
-
- if (!indirect_rate_sampling) {
- if (msr->sample_limit != 0) {
- ndx = sample_ndx;
- mi->sample_count++;
- if (msr->sample_limit > 0)
- msr->sample_limit--;
- } else
- rate_sampling = false;
- } else {
- /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark
- * packets that have the sampling rate deferred to the
- * second MRR stage. Increase the sample counter only
- * if the deferred sample rate was actually used.
- * Use the sample_deferred counter to make sure that
- * the sampling is not done in large bursts */
- info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
- mi->sample_deferred++;
- }
+ if (mi->packet_count >= 10000) {
+ mi->sample_deferred = 0;
+ mi->sample_count = 0;
+ mi->packet_count = 0;
+ } else if (delta > mi->n_rates * 2) {
+ /* With multi-rate retry, not every planned sample
+ * attempt actually gets used, due to the way the retry
+ * chain is set up - [max_tp,sample,prob,lowest] for
+ * sample_rate < max_tp.
+ *
+ * If there's too much sampling backlog and the link
+ * starts getting worse, minstrel would start bursting
+ * out lots of sampling frames, which would result
+ * in a large throughput loss. */
+ mi->sample_count += (delta - mi->n_rates * 2);
+ }
+
+ /* get next random rate sample */
+ ndx = minstrel_get_next_sample(mi);
+ msr = &mi->r[ndx];
+ mr = &mi->r[mi->max_tp_rate[0]];
+
+ /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage)
+ * rate sampling method should be used.
+ * Respect such rates that are not sampled for 20 interations.
+ */
+ if (mrr_capable &&
+ msr->perfect_tx_time > mr->perfect_tx_time &&
+ msr->sample_skipped < 20) {
+ /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark
+ * packets that have the sampling rate deferred to the
+ * second MRR stage. Increase the sample counter only
+ * if the deferred sample rate was actually used.
+ * Use the sample_deferred counter to make sure that
+ * the sampling is not done in large bursts */
+ info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
+ rate++;
+ mi->sample_deferred++;
+ } else {
+ if (!msr->sample_limit != 0)
+ return;
+
+ mi->sample_count++;
+ if (msr->sample_limit > 0)
+ msr->sample_limit--;
}
- mi->prev_sample = rate_sampling;

/* If we're not using MRR and the sampling rate already
* has a probability of >95%, we shouldn't be attempting
* to use it, as this only wastes precious airtime */
- if (!mrr_capable && rate_sampling &&
+ if (!mrr_capable &&
(mi->r[ndx].probability > MINSTREL_FRAC(95, 100)))
- ndx = mi->max_tp_rate[0];
-
- /* mrr setup for 1st stage */
- ar[0].idx = mi->r[ndx].rix;
- ar[0].count = minstrel_get_retry_count(&mi->r[ndx], info);
-
- /* non mrr setup for 2nd stage */
- if (!mrr_capable) {
- if (!rate_sampling)
- ar[0].count = mp->max_retry;
- ar[1].idx = mi->lowest_rix;
- ar[1].count = mp->max_retry;
return;
- }

- /* mrr setup for 2nd stage */
- if (rate_sampling) {
- if (indirect_rate_sampling)
- mrr_ndx[0] = sample_ndx;
- else
- mrr_ndx[0] = mi->max_tp_rate[0];
- } else {
- mrr_ndx[0] = mi->max_tp_rate[1];
- }
+ mi->prev_sample = true;

- /* mrr setup for 3rd & 4th stage */
- mrr_ndx[1] = mi->max_prob_rate;
- mrr_ndx[2] = 0;
- for (i = 1; i < 4; i++) {
- ar[i].idx = mi->r[mrr_ndx[i - 1]].rix;
- ar[i].count = mi->r[mrr_ndx[i - 1]].adjusted_retry_count;
- }
+ rate->idx = mi->r[ndx].rix;
+ rate->count = minstrel_get_retry_count(&mi->r[ndx], info);
}


@@ -412,12 +425,16 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
unsigned int i, n = 0;
unsigned int t_slot = 9; /* FIXME: get real slot time */

+ 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);

+ memset(mi->max_tp_rate, 0, sizeof(mi->max_tp_rate));
+ mi->max_prob_rate = 0;
+
for (i = 0; i < sband->n_bitrates; i++) {
struct minstrel_rate *mr = &mi->r[n];
unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0;
@@ -473,6 +490,7 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
mi->stats_update = jiffies;

init_sample_table(mi);
+ minstrel_update_rates(mp, mi);
}

static void *
diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index b9f8535..f4301f4 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -63,6 +63,8 @@ struct minstrel_rate {
};

struct minstrel_sta_info {
+ struct ieee80211_sta *sta;
+
unsigned long stats_update;
unsigned int sp_ack_dur;
unsigned int rate_avg;
--
1.8.0.2