From c12abae333ac550acacf9d324ed54b7d17ead0c0 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 14 Oct 2008 16:56:51 +0200 Subject: [PATCH] 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 Cc: Christian Lamparter Signed-off-by: John W. Linville --- drivers/net/wireless/p54/p54common.c | 130 ++++++++++++++++++++++----- 1 file changed, 108 insertions(+), 22 deletions(-) diff --git a/drivers/net/wireless/p54/p54common.c b/drivers/net/wireless/p54/p54common.c index 65be5eca2340..237090140243 100644 --- a/drivers/net/wireless/p54/p54common.c +++ b/drivers/net/wireless/p54/p54common.c @@ -1,9 +1,9 @@ - /* * Common code for mac80211 Prism54 drivers * * Copyright (c) 2006, Michael Wu * Copyright (c) 2007, Christian Lamparter + * Copyright 2008, Johannes Berg * * Based on the islsm (softmac prism54) driver, which is: * Copyright 2004-2006 Jean-Baptiste Note , 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; - - /* 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; + 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 (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; + + /* 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; } - memset(txhdr->rateset, rate, 8); + + 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); -- GitLab