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@xxxxxxxxxxxxxxxx>
Cc: Christian Lamparter <chunkeey@xxxxxx>
---
drivers/net/wireless/p54/p54common.c | 130 +++++++++++++++++++++++++++++------
1 file changed, 108 insertions(+), 22 deletions(-)
--- everything.orig/drivers/net/wireless/p54/p54common.c 2008-10-14 16:52:43.000000000 +0200
+++ everything/drivers/net/wireless/p54/p54common.c 2008-10-14 16:53:37.000000000 +0200
@@ -1,9 +1,9 @@
-
/*
* Common code for mac80211 Prism54 drivers
*
* Copyright (c) 2006, Michael Wu <flamingice@xxxxxxxxxxxx>
* Copyright (c) 2007, Christian Lamparter <chunkeey@xxxxxx>
+ * Copyright 2008, Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
*
* Based on the islsm (softmac prism54) driver, which is:
* Copyright 2004-2006 Jean-Baptiste Note <jbnote@xxxxxxxxx>, et al.
@@ -552,6 +552,7 @@ static void p54_rx_frame_sent(struct iee
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) {
@@ -576,18 +577,39 @@ static void p54_rx_frame_sent(struct iee
__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));
@@ -810,9 +832,12 @@ static int p54_tx(struct ieee80211_hw *d
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))
@@ -835,23 +860,74 @@ static int p54_tx(struct ieee80211_hw *d
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;
+
+ /*
+ * 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++;
+ }
+
+ /* 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];
+ }
+
+ /* 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 */
- /* 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;
- }
- 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;
+ 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++;
+ }
}
- memset(txhdr->rateset, rate, 8);
+ hdr->retry2 = ridx;
+
txhdr->key_type = 0;
txhdr->key_len = 0;
txhdr->hw_queue = skb_get_queue_mapping(skb) + 4;
@@ -1401,6 +1477,16 @@ struct ieee80211_hw *p54_init_common(siz
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);
--
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