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mt76: mt7615: sync with mt7603 rate control changes
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- Store the previous and current rate set in the driver + the TSF value
  at the time of the switch.
- Use the tx status TSF value to determine which rate set needs to be used
  as reference.
- Report only short or long GI rates for a single status event, not a mix.
- The hardware reports the last used rate index. Use it along with the
  retry count to figure out what rate was used for the first attempt.
- Use the same retry count value for all rate slots to make this calculation
  work.
- Derive the probe rate from the current rateset instead of the skb cb
- Do not wait for a status report for the probe frame before removing the
  probe rate from the rate table. Do it immediately after it was referenced
  in a tx status report.
- Use the first half of the first rate retry budget for the probe rate
  in order to avoid using too many retries on that rate
- Switch from lower rates to higher rates more conservatively
- enable hardware rate up/down selection

Signed-off-by: Felix Fietkau <nbd@nbd.name>
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@nbd168
nbd168 committed Jul 3, 2019
1 parent 2ae01f7 commit 6f98378
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Showing 4 changed files with 124 additions and 44 deletions.
19 changes: 13 additions & 6 deletions mt7615/init.c
View file
Expand Up @@ -45,11 +45,19 @@ static void mt7615_mac_init(struct mt7615_dev *dev)
mt76_wr(dev, MT_DMA_DCR0, MT_DMA_DCR0_RX_VEC_DROP |
FIELD_PREP(MT_DMA_DCR0_MAX_RX_LEN, 3072));

mt76_wr(dev, MT_AGG_ARUCR, FIELD_PREP(MT_AGG_ARxCR_LIMIT(0), 7));
mt76_wr(dev, MT_AGG_ARUCR,
FIELD_PREP(MT_AGG_ARxCR_LIMIT(0), 7) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(1), 2) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(2), 2) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(3), 2) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(4), 1) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(5), 1) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(6), 1) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(7), 1));

mt76_wr(dev, MT_AGG_ARDCR,
FIELD_PREP(MT_AGG_ARxCR_LIMIT(0), 0) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(1),
max_t(int, 0, MT7615_RATE_RETRY - 2)) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(0), MT7615_RATE_RETRY - 1) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(1), MT7615_RATE_RETRY - 1) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(2), MT7615_RATE_RETRY - 1) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(3), MT7615_RATE_RETRY - 1) |
FIELD_PREP(MT_AGG_ARxCR_LIMIT(4), MT7615_RATE_RETRY - 1) |
Expand All @@ -58,8 +66,7 @@ static void mt7615_mac_init(struct mt7615_dev *dev)
FIELD_PREP(MT_AGG_ARxCR_LIMIT(7), MT7615_RATE_RETRY - 1));

mt76_wr(dev, MT_AGG_ARCR,
(MT_AGG_ARCR_INIT_RATE1 |
FIELD_PREP(MT_AGG_ARCR_RTS_RATE_THR, 2) |
(FIELD_PREP(MT_AGG_ARCR_RTS_RATE_THR, 2) |
MT_AGG_ARCR_RATE_DOWN_RATIO_EN |
FIELD_PREP(MT_AGG_ARCR_RATE_DOWN_RATIO, 1) |
FIELD_PREP(MT_AGG_ARCR_RATE_UP_EXTRA_TH, 4)));
Expand Down
129 changes: 92 additions & 37 deletions mt7615/mac.c
View file
Expand Up @@ -451,6 +451,7 @@ void mt7615_mac_set_rates(struct mt7615_dev *dev, struct mt7615_sta *sta,
struct ieee80211_tx_rate *probe_rate,
struct ieee80211_tx_rate *rates)
{
struct ieee80211_tx_rate *ref;
int wcid = sta->wcid.idx;
u32 addr = MT_WTBL_BASE + wcid * MT_WTBL_ENTRY_SIZE;
bool stbc = false;
Expand All @@ -459,14 +460,52 @@ void mt7615_mac_set_rates(struct mt7615_dev *dev, struct mt7615_sta *sta,
u16 val[4];
u16 probe_val;
u32 w5, w27;
int i;
bool rateset;
int i, k;

if (!mt76_poll(dev, MT_WTBL_UPDATE, MT_WTBL_UPDATE_BUSY, 0, 5000))
return;

for (i = n_rates; i < 4; i++)
rates[i] = rates[n_rates - 1];

rateset = !(sta->rate_set_tsf & BIT(0));
memcpy(sta->rateset[rateset].rates, rates,
sizeof(sta->rateset[rateset].rates));
if (probe_rate) {
sta->rateset[rateset].probe_rate = *probe_rate;
ref = &sta->rateset[rateset].probe_rate;
} else {
sta->rateset[rateset].probe_rate.idx = -1;
ref = &sta->rateset[rateset].rates[0];
}

rates = sta->rateset[rateset].rates;
for (i = 0; i < ARRAY_SIZE(sta->rateset[rateset].rates); i++) {
/*
* We don't support switching between short and long GI
* within the rate set. For accurate tx status reporting, we
* need to make sure that flags match.
* For improved performance, avoid duplicate entries by
* decrementing the MCS index if necessary
*/
if ((ref->flags ^ rates[i].flags) & IEEE80211_TX_RC_SHORT_GI)
rates[i].flags ^= IEEE80211_TX_RC_SHORT_GI;

for (k = 0; k < i; k++) {
if (rates[i].idx != rates[k].idx)
continue;
if ((rates[i].flags ^ rates[k].flags) &
(IEEE80211_TX_RC_40_MHZ_WIDTH |
IEEE80211_TX_RC_80_MHZ_WIDTH |
IEEE80211_TX_RC_160_MHZ_WIDTH))
continue;

rates[i].idx--;
}

}

val[0] = mt7615_mac_tx_rate_val(dev, &rates[0], stbc, &bw);
bw_prev = bw;

Expand Down Expand Up @@ -513,17 +552,17 @@ void mt7615_mac_set_rates(struct mt7615_dev *dev, struct mt7615_sta *sta,
mt76_wr(dev, MT_WTBL_RIUCR1,
FIELD_PREP(MT_WTBL_RIUCR1_RATE0, probe_val) |
FIELD_PREP(MT_WTBL_RIUCR1_RATE1, val[0]) |
FIELD_PREP(MT_WTBL_RIUCR1_RATE2_LO, val[0]));
FIELD_PREP(MT_WTBL_RIUCR1_RATE2_LO, val[1]));

mt76_wr(dev, MT_WTBL_RIUCR2,
FIELD_PREP(MT_WTBL_RIUCR2_RATE2_HI, val[0] >> 8) |
FIELD_PREP(MT_WTBL_RIUCR2_RATE2_HI, val[1] >> 8) |
FIELD_PREP(MT_WTBL_RIUCR2_RATE3, val[1]) |
FIELD_PREP(MT_WTBL_RIUCR2_RATE4, val[1]) |
FIELD_PREP(MT_WTBL_RIUCR2_RATE4, val[2]) |
FIELD_PREP(MT_WTBL_RIUCR2_RATE5_LO, val[2]));

mt76_wr(dev, MT_WTBL_RIUCR3,
FIELD_PREP(MT_WTBL_RIUCR3_RATE5_HI, val[2] >> 4) |
FIELD_PREP(MT_WTBL_RIUCR3_RATE6, val[2]) |
FIELD_PREP(MT_WTBL_RIUCR3_RATE6, val[3]) |
FIELD_PREP(MT_WTBL_RIUCR3_RATE7, val[3]));

mt76_wr(dev, MT_WTBL_UPDATE,
Expand All @@ -533,6 +572,9 @@ void mt7615_mac_set_rates(struct mt7615_dev *dev, struct mt7615_sta *sta,

mt76_wr(dev, addr + 27 * 4, w27);

mt76_set(dev, MT_LPON_T0CR, MT_LPON_T0CR_MODE); /* TSF read */
sta->rate_set_tsf = (mt76_rr(dev, MT_LPON_UTTR0) & ~BIT(0)) | rateset;

if (!(sta->wcid.tx_info & MT_WCID_TX_INFO_SET))
mt76_poll(dev, MT_WTBL_UPDATE, MT_WTBL_UPDATE_BUSY, 0, 5000);

Expand Down Expand Up @@ -562,9 +604,9 @@ int mt7615_tx_prepare_skb(struct mt76_dev *mdev, void *txwi_ptr,

if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) {
spin_lock_bh(&dev->mt76.lock);
msta->rate_probe = true;
mt7615_mac_set_rates(dev, msta, &info->control.rates[0],
msta->rates);
msta->rate_probe = true;
spin_unlock_bh(&dev->mt76.lock);
}

Expand Down Expand Up @@ -616,9 +658,13 @@ static bool mt7615_fill_txs(struct mt7615_dev *dev, struct mt7615_sta *sta,
struct ieee80211_tx_info *info, __le32 *txs_data)
{
struct ieee80211_supported_band *sband;
int i, idx, count, final_idx = 0;
struct mt7615_rate_set *rs;
int first_idx = 0, last_idx;
int i, idx, count;
bool fixed_rate, ack_timeout;
bool probe, ampdu, cck = false;
bool rs_idx;
u32 rate_set_tsf;
u32 final_rate, final_rate_flags, final_nss, txs;

fixed_rate = info->status.rates[0].count;
Expand All @@ -629,6 +675,7 @@ static bool mt7615_fill_txs(struct mt7615_dev *dev, struct mt7615_sta *sta,

txs = le32_to_cpu(txs_data[3]);
count = FIELD_GET(MT_TXS3_TX_COUNT, txs);
last_idx = FIELD_GET(MT_TXS3_LAST_TX_RATE, txs);

txs = le32_to_cpu(txs_data[0]);
final_rate = FIELD_GET(MT_TXS0_TX_RATE, txs);
Expand All @@ -650,38 +697,56 @@ static bool mt7615_fill_txs(struct mt7615_dev *dev, struct mt7615_sta *sta,
if (ampdu || (info->flags & IEEE80211_TX_CTL_AMPDU))
info->flags |= IEEE80211_TX_STAT_AMPDU | IEEE80211_TX_CTL_AMPDU;

first_idx = max_t(int, 0, last_idx - (count + 1) / MT7615_RATE_RETRY);

if (fixed_rate && !probe) {
info->status.rates[0].count = count;
i = 0;
goto out;
}

for (i = 0, idx = 0; i < ARRAY_SIZE(info->status.rates); i++) {
int cur_count = min_t(int, count, 2 * MT7615_RATE_RETRY);
rate_set_tsf = READ_ONCE(sta->rate_set_tsf);
rs_idx = !((u32)(FIELD_GET(MT_TXS4_F0_TIMESTAMP, le32_to_cpu(txs_data[4])) -
rate_set_tsf) < 1000000);
rs_idx ^= rate_set_tsf & BIT(0);
rs = &sta->rateset[rs_idx];

if (!i && probe) {
cur_count = 1;
} else {
info->status.rates[i] = sta->rates[idx];
idx++;
}
if (!first_idx && rs->probe_rate.idx >= 0) {
info->status.rates[0] = rs->probe_rate;

if (i && info->status.rates[i].idx < 0) {
info->status.rates[i - 1].count += count;
break;
spin_lock_bh(&dev->mt76.lock);
if (sta->rate_probe) {
mt7615_mac_set_rates(dev, sta, NULL, sta->rates);
sta->rate_probe = false;
}
spin_unlock_bh(&dev->mt76.lock);
} else
info->status.rates[0] = rs->rates[first_idx / 2];
info->status.rates[0].count = 0;

if (!count) {
info->status.rates[i].idx = -1;
break;
}
for (i = 0, idx = first_idx; count && idx <= last_idx; idx++) {
struct ieee80211_tx_rate *cur_rate;
int cur_count;

info->status.rates[i].count = cur_count;
final_idx = i;
cur_rate = &rs->rates[idx / 2];
cur_count = min_t(int, MT7615_RATE_RETRY, count);
count -= cur_count;

if (idx && (cur_rate->idx != info->status.rates[i].idx ||
cur_rate->flags != info->status.rates[i].flags)) {
i++;
if (i == ARRAY_SIZE(info->status.rates))
break;

info->status.rates[i] = *cur_rate;
info->status.rates[i].count = 0;
}

info->status.rates[i].count += cur_count;
}

out:
final_rate_flags = info->status.rates[final_idx].flags;
final_rate_flags = info->status.rates[i].flags;

switch (FIELD_GET(MT_TX_RATE_MODE, final_rate)) {
case MT_PHY_TYPE_CCK:
Expand Down Expand Up @@ -713,8 +778,8 @@ static bool mt7615_fill_txs(struct mt7615_dev *dev, struct mt7615_sta *sta,
return false;
}

info->status.rates[final_idx].idx = final_rate;
info->status.rates[final_idx].flags = final_rate_flags;
info->status.rates[i].idx = final_rate;
info->status.rates[i].flags = final_rate_flags;

return true;
}
Expand All @@ -735,16 +800,6 @@ static bool mt7615_mac_add_txs_skb(struct mt7615_dev *dev,
if (skb) {
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);

if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) {
spin_lock_bh(&dev->mt76.lock);
if (sta->rate_probe) {
mt7615_mac_set_rates(dev, sta, NULL,
sta->rates);
sta->rate_probe = false;
}
spin_unlock_bh(&dev->mt76.lock);
}

if (!mt7615_fill_txs(dev, sta, info, txs_data)) {
ieee80211_tx_info_clear_status(info);
info->status.rates[0].idx = -1;
Expand Down
11 changes: 10 additions & 1 deletion mt7615/mt7615.h
View file
Expand Up @@ -42,12 +42,21 @@ enum mt7615_hw_txq_id {
MT7615_TXQ_FWDL,
};

struct mt7615_rate_set {
struct ieee80211_tx_rate probe_rate;
struct ieee80211_tx_rate rates[4];
};

struct mt7615_sta {
struct mt76_wcid wcid; /* must be first */

struct mt7615_vif *vif;

struct ieee80211_tx_rate rates[8];
struct ieee80211_tx_rate rates[4];

struct mt7615_rate_set rateset[2];
u32 rate_set_tsf;

u8 rate_count;
u8 n_rates;

Expand Down
9 changes: 9 additions & 0 deletions mt7615/regs.h
View file
Expand Up @@ -187,6 +187,15 @@

#define MT_WTBL_W27_CC_BW_SEL GENMASK(6, 5)

#define MT_LPON_BASE 0x24200
#define MT_LPON(_n) (MT_LPON_BASE + (_n))

#define MT_LPON_T0CR MT_LPON(0x010)
#define MT_LPON_T0CR_MODE GENMASK(1, 0)

#define MT_LPON_UTTR0 MT_LPON(0x018)
#define MT_LPON_UTTR1 MT_LPON(0x01c)

#define MT_EFUSE_BASE 0x81070000
#define MT_EFUSE_BASE_CTRL 0x000
#define MT_EFUSE_BASE_CTRL_EMPTY BIT(30)
Expand Down

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