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p54: implement MRR 

This implements multi-rate retry in p54. With lots of help
and testing from Christian and the limiting idea from nbd.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2008-10-14 16:56:51 +02:00 committed by John W. Linville
parent e6a9854b05
commit c12abae333
1 changed files with 107 additions and 21 deletions
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128
drivers/net/wireless/p54/p54common.c
View File

@ -1,9 +1,9 @@
/*
* Common code for mac80211 Prism54 drivers
*
* Copyright (c) 2006, Michael Wu <flamingice@sourmilk.net>
* Copyright (c) 2007, Christian Lamparter <chunkeey@web.de>
* Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
*
* Based on the islsm (softmac prism54) driver, which is:
* Copyright 2004-2006 Jean-Baptiste Note <jbnote@gmail.com>, et al.
@ -544,6 +544,7 @@ static void p54_rx_frame_sent(struct ieee80211_hw *dev, struct sk_buff *skb)
u32 freed = 0;
u32 last_addr = priv->rx_start;
unsigned long flags;
int count, idx;
spin_lock_irqsave(&priv->tx_queue.lock, flags);
while (entry != (struct sk_buff *)&priv->tx_queue) {
@ -568,18 +569,39 @@ static void p54_rx_frame_sent(struct ieee80211_hw *dev, struct sk_buff *skb)
__skb_unlink(entry, &priv->tx_queue);
spin_unlock_irqrestore(&priv->tx_queue.lock, flags);
ieee80211_tx_info_clear_status(info);
/*
* Clear manually, ieee80211_tx_info_clear_status would
* clear the counts too and we need them.
*/
memset(&info->status.ampdu_ack_len, 0,
sizeof(struct ieee80211_tx_info) -
offsetof(struct ieee80211_tx_info, status.ampdu_ack_len));
BUILD_BUG_ON(offsetof(struct ieee80211_tx_info,
status.ampdu_ack_len) != 23);
entry_hdr = (struct p54_control_hdr *) entry->data;
entry_data = (struct p54_tx_control_allocdata *) entry_hdr->data;
if ((entry_hdr->magic1 & cpu_to_le16(0x4000)) != 0)
pad = entry_data->align[0];
priv->tx_stats[entry_data->hw_queue].len--;
if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
if (!(payload->status & 0x01))
info->flags |= IEEE80211_TX_STAT_ACK;
/* walk through the rates array and adjust the counts */
count = payload->retries;
for (idx = 0; idx < 4; idx++) {
if (count >= info->status.rates[idx].count) {
count -= info->status.rates[idx].count;
} else if (count > 0) {
info->status.rates[idx].count = count;
count = 0;
} else {
info->status.rates[idx].idx = -1;
info->status.rates[idx].count = 0;
}
}
info->status.rates[0].count = payload->retries;
priv->tx_stats[entry_data->hw_queue].len--;
if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
!(payload->status & 0x01))
info->flags |= IEEE80211_TX_STAT_ACK;
info->status.ack_signal = p54_rssi_to_dbm(dev,
le16_to_cpu(payload->ack_rssi));
skb_pull(entry, sizeof(*hdr) + pad + sizeof(*entry_data));
@ -802,9 +824,12 @@ static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
struct p54_control_hdr *hdr;
struct p54_tx_control_allocdata *txhdr;
size_t padding, len;
int i, j, ridx;
u8 rate;
u8 cts_rate = 0x20;
u8 rc_flags;
u8 calculated_tries[4];
u8 nrates = 0, nremaining = 8;
current_queue = &priv->tx_stats[skb_get_queue_mapping(skb) + 4];
if (unlikely(current_queue->len > current_queue->limit))
@ -827,23 +852,74 @@ static int p54_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
hdr->magic1 = cpu_to_le16(0x0010);
hdr->len = cpu_to_le16(len);
hdr->type = (info->flags & IEEE80211_TX_CTL_NO_ACK) ? 0 : cpu_to_le16(1);
hdr->retry1 = hdr->retry2 = info->control.rates[0].count;
hdr->retry1 = info->control.rates[0].count;
/* TODO: add support for alternate retry TX rates */
rate = ieee80211_get_tx_rate(dev, info)->hw_value;
rc_flags = info->control.rates[0].flags;
if (rc_flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE) {
rate |= 0x10;
cts_rate |= 0x10;
/*
* we register the rates in perfect order, and
* RTS/CTS won't happen on 5 GHz
*/
cts_rate = info->control.rts_cts_rate_idx;
memset(&txhdr->rateset, 0, sizeof(txhdr->rateset));
/* see how many rates got used */
for (i = 0; i < 4; i++) {
if (info->control.rates[i].idx < 0)
break;
nrates++;
}
if (rc_flags & IEEE80211_TX_RC_USE_RTS_CTS) {
rate |= 0x40;
cts_rate |= ieee80211_get_rts_cts_rate(dev, info)->hw_value;
} else if (rc_flags & IEEE80211_TX_RC_USE_CTS_PROTECT) {
rate |= 0x20;
cts_rate |= ieee80211_get_rts_cts_rate(dev, info)->hw_value;
/* limit tries to 8/nrates per rate */
for (i = 0; i < nrates; i++) {
/*
* The magic expression here is equivalent to 8/nrates for
* all values that matter, but avoids division and jumps.
* Note that nrates can only take the values 1 through 4.
*/
calculated_tries[i] = min_t(int, ((15 >> nrates) | 1) + 1,
info->control.rates[i].count);
nremaining -= calculated_tries[i];
}
memset(txhdr->rateset, rate, 8);
/* if there are tries left, distribute from back to front */
for (i = nrates - 1; nremaining > 0 && i >= 0; i--) {
int tmp = info->control.rates[i].count - calculated_tries[i];
if (tmp <= 0)
continue;
/* RC requested more tries at this rate */
tmp = min_t(int, tmp, nremaining);
calculated_tries[i] += tmp;
nremaining -= tmp;
}
ridx = 0;
for (i = 0; i < nrates && ridx < 8; i++) {
/* we register the rates in perfect order */
rate = info->control.rates[i].idx;
if (info->band == IEEE80211_BAND_5GHZ)
rate += 4;
/* store the count we actually calculated for TX status */
info->control.rates[i].count = calculated_tries[i];
rc_flags = info->control.rates[i].flags;
if (rc_flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE) {
rate |= 0x10;
cts_rate |= 0x10;
}
if (rc_flags & IEEE80211_TX_RC_USE_RTS_CTS)
rate |= 0x40;
else if (rc_flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
rate |= 0x20;
for (j = 0; j < calculated_tries[i] && ridx < 8; j++) {
txhdr->rateset[ridx] = rate;
ridx++;
}
}
hdr->retry2 = ridx;
txhdr->key_type = 0;
txhdr->key_len = 0;
txhdr->hw_queue = skb_get_queue_mapping(skb) + 4;
@ -1393,6 +1469,16 @@ struct ieee80211_hw *p54_init_common(size_t priv_data_len)
priv->tx_stats[4].limit = 5;
dev->queues = 1;
priv->noise = -94;
/*
* We support at most 8 tries no matter which rate they're at,
* we cannot support max_rates * max_rate_tries as we set it
* here, but setting it correctly to 4/2 or so would limit us
* artificially if the RC algorithm wants just two rates, so
* let's say 4/7, we'll redistribute it at TX time, see the
* comments there.
*/
dev->max_rates = 4;
dev->max_rate_tries = 7;
dev->extra_tx_headroom = sizeof(struct p54_control_hdr) + 4 +
sizeof(struct p54_tx_control_allocdata);