diff options
Diffstat (limited to 'drivers/net/wireless/iwlegacy/iwl-3945-rs.c')
| -rw-r--r-- | drivers/net/wireless/iwlegacy/iwl-3945-rs.c | 994 |
1 files changed, 994 insertions, 0 deletions
diff --git a/drivers/net/wireless/iwlegacy/iwl-3945-rs.c b/drivers/net/wireless/iwlegacy/iwl-3945-rs.c new file mode 100644 index 00000000000..977bd2477c6 --- /dev/null +++ b/drivers/net/wireless/iwlegacy/iwl-3945-rs.c @@ -0,0 +1,994 @@ +/****************************************************************************** + * + * Copyright(c) 2005 - 2011 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA + * + * The full GNU General Public License is included in this distribution in the + * file called LICENSE. + * + * Contact Information: + * Intel Linux Wireless <ilw@linux.intel.com> + * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497 + * + *****************************************************************************/ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/wireless.h> +#include <net/mac80211.h> + +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/delay.h> + +#include <linux/workqueue.h> + +#include "iwl-commands.h" +#include "iwl-3945.h" +#include "iwl-sta.h" + +#define RS_NAME "iwl-3945-rs" + +static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT_3945] = { + 7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202 +}; + +static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT_3945] = { + 7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125 +}; + +static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT_3945] = { + 0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186 +}; + +static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT_3945] = { + 7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0 +}; + +struct iwl3945_tpt_entry { + s8 min_rssi; + u8 index; +}; + +static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = { + {-60, IWL_RATE_54M_INDEX}, + {-64, IWL_RATE_48M_INDEX}, + {-72, IWL_RATE_36M_INDEX}, + {-80, IWL_RATE_24M_INDEX}, + {-84, IWL_RATE_18M_INDEX}, + {-85, IWL_RATE_12M_INDEX}, + {-87, IWL_RATE_9M_INDEX}, + {-89, IWL_RATE_6M_INDEX} +}; + +static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = { + {-60, IWL_RATE_54M_INDEX}, + {-64, IWL_RATE_48M_INDEX}, + {-68, IWL_RATE_36M_INDEX}, + {-80, IWL_RATE_24M_INDEX}, + {-84, IWL_RATE_18M_INDEX}, + {-85, IWL_RATE_12M_INDEX}, + {-86, IWL_RATE_11M_INDEX}, + {-88, IWL_RATE_5M_INDEX}, + {-90, IWL_RATE_2M_INDEX}, + {-92, IWL_RATE_1M_INDEX} +}; + +#define IWL_RATE_MAX_WINDOW 62 +#define IWL_RATE_FLUSH (3*HZ) +#define IWL_RATE_WIN_FLUSH (HZ/2) +#define IWL39_RATE_HIGH_TH 11520 +#define IWL_SUCCESS_UP_TH 8960 +#define IWL_SUCCESS_DOWN_TH 10880 +#define IWL_RATE_MIN_FAILURE_TH 6 +#define IWL_RATE_MIN_SUCCESS_TH 8 +#define IWL_RATE_DECREASE_TH 1920 +#define IWL_RATE_RETRY_TH 15 + +static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band) +{ + u32 index = 0; + u32 table_size = 0; + struct iwl3945_tpt_entry *tpt_table = NULL; + + if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL)) + rssi = IWL_MIN_RSSI_VAL; + + switch (band) { + case IEEE80211_BAND_2GHZ: + tpt_table = iwl3945_tpt_table_g; + table_size = ARRAY_SIZE(iwl3945_tpt_table_g); + break; + + case IEEE80211_BAND_5GHZ: + tpt_table = iwl3945_tpt_table_a; + table_size = ARRAY_SIZE(iwl3945_tpt_table_a); + break; + + default: + BUG(); + break; + } + + while ((index < table_size) && (rssi < tpt_table[index].min_rssi)) + index++; + + index = min(index, (table_size - 1)); + + return tpt_table[index].index; +} + +static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window) +{ + window->data = 0; + window->success_counter = 0; + window->success_ratio = -1; + window->counter = 0; + window->average_tpt = IWL_INVALID_VALUE; + window->stamp = 0; +} + +/** + * iwl3945_rate_scale_flush_windows - flush out the rate scale windows + * + * Returns the number of windows that have gathered data but were + * not flushed. If there were any that were not flushed, then + * reschedule the rate flushing routine. + */ +static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta) +{ + int unflushed = 0; + int i; + unsigned long flags; + struct iwl_priv *priv __maybe_unused = rs_sta->priv; + + /* + * For each rate, if we have collected data on that rate + * and it has been more than IWL_RATE_WIN_FLUSH + * since we flushed, clear out the gathered statistics + */ + for (i = 0; i < IWL_RATE_COUNT_3945; i++) { + if (!rs_sta->win[i].counter) + continue; + + spin_lock_irqsave(&rs_sta->lock, flags); + if (time_after(jiffies, rs_sta->win[i].stamp + + IWL_RATE_WIN_FLUSH)) { + IWL_DEBUG_RATE(priv, "flushing %d samples of rate " + "index %d\n", + rs_sta->win[i].counter, i); + iwl3945_clear_window(&rs_sta->win[i]); + } else + unflushed++; + spin_unlock_irqrestore(&rs_sta->lock, flags); + } + + return unflushed; +} + +#define IWL_RATE_FLUSH_MAX 5000 /* msec */ +#define IWL_RATE_FLUSH_MIN 50 /* msec */ +#define IWL_AVERAGE_PACKETS 1500 + +static void iwl3945_bg_rate_scale_flush(unsigned long data) +{ + struct iwl3945_rs_sta *rs_sta = (void *)data; + struct iwl_priv *priv __maybe_unused = rs_sta->priv; + int unflushed = 0; + unsigned long flags; + u32 packet_count, duration, pps; + + IWL_DEBUG_RATE(priv, "enter\n"); + + unflushed = iwl3945_rate_scale_flush_windows(rs_sta); + + spin_lock_irqsave(&rs_sta->lock, flags); + + /* Number of packets Rx'd since last time this timer ran */ + packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1; + + rs_sta->last_tx_packets = rs_sta->tx_packets + 1; + + if (unflushed) { + duration = + jiffies_to_msecs(jiffies - rs_sta->last_partial_flush); + + IWL_DEBUG_RATE(priv, "Tx'd %d packets in %dms\n", + packet_count, duration); + + /* Determine packets per second */ + if (duration) + pps = (packet_count * 1000) / duration; + else + pps = 0; + + if (pps) { + duration = (IWL_AVERAGE_PACKETS * 1000) / pps; + if (duration < IWL_RATE_FLUSH_MIN) + duration = IWL_RATE_FLUSH_MIN; + else if (duration > IWL_RATE_FLUSH_MAX) + duration = IWL_RATE_FLUSH_MAX; + } else + duration = IWL_RATE_FLUSH_MAX; + + rs_sta->flush_time = msecs_to_jiffies(duration); + + IWL_DEBUG_RATE(priv, "new flush period: %d msec ave %d\n", + duration, packet_count); + + mod_timer(&rs_sta->rate_scale_flush, jiffies + + rs_sta->flush_time); + + rs_sta->last_partial_flush = jiffies; + } else { + rs_sta->flush_time = IWL_RATE_FLUSH; + rs_sta->flush_pending = 0; + } + /* If there weren't any unflushed entries, we don't schedule the timer + * to run again */ + + rs_sta->last_flush = jiffies; + + spin_unlock_irqrestore(&rs_sta->lock, flags); + + IWL_DEBUG_RATE(priv, "leave\n"); +} + +/** + * iwl3945_collect_tx_data - Update the success/failure sliding window + * + * We keep a sliding window of the last 64 packets transmitted + * at this rate. window->data contains the bitmask of successful + * packets. + */ +static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta, + struct iwl3945_rate_scale_data *window, + int success, int retries, int index) +{ + unsigned long flags; + s32 fail_count; + struct iwl_priv *priv __maybe_unused = rs_sta->priv; + + if (!retries) { + IWL_DEBUG_RATE(priv, "leave: retries == 0 -- should be at least 1\n"); + return; + } + + spin_lock_irqsave(&rs_sta->lock, flags); + + /* + * Keep track of only the latest 62 tx frame attempts in this rate's + * history window; anything older isn't really relevant any more. + * If we have filled up the sliding window, drop the oldest attempt; + * if the oldest attempt (highest bit in bitmap) shows "success", + * subtract "1" from the success counter (this is the main reason + * we keep these bitmaps!). + * */ + while (retries > 0) { + if (window->counter >= IWL_RATE_MAX_WINDOW) { + + /* remove earliest */ + window->counter = IWL_RATE_MAX_WINDOW - 1; + + if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1))) { + window->data &= ~(1ULL << (IWL_RATE_MAX_WINDOW - 1)); + window->success_counter--; + } + } + + /* Increment frames-attempted counter */ + window->counter++; + + /* Shift bitmap by one frame (throw away oldest history), + * OR in "1", and increment "success" if this + * frame was successful. */ + window->data <<= 1; + if (success > 0) { + window->success_counter++; + window->data |= 0x1; + success--; + } + + retries--; + } + + /* Calculate current success ratio, avoid divide-by-0! */ + if (window->counter > 0) + window->success_ratio = 128 * (100 * window->success_counter) + / window->counter; + else + window->success_ratio = IWL_INVALID_VALUE; + + fail_count = window->counter - window->success_counter; + + /* Calculate average throughput, if we have enough history. */ + if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) || + (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH)) + window->average_tpt = ((window->success_ratio * + rs_sta->expected_tpt[index] + 64) / 128); + else + window->average_tpt = IWL_INVALID_VALUE; + + /* Tag this window as having been updated */ + window->stamp = jiffies; + + spin_unlock_irqrestore(&rs_sta->lock, flags); + +} + +/* + * Called after adding a new station to initialize rate scaling + */ +void iwl3945_rs_rate_init(struct iwl_priv *priv, struct ieee80211_sta *sta, u8 sta_id) +{ + struct ieee80211_hw *hw = priv->hw; + struct ieee80211_conf *conf = &priv->hw->conf; + struct iwl3945_sta_priv *psta; + struct iwl3945_rs_sta *rs_sta; + struct ieee80211_supported_band *sband; + int i; + + IWL_DEBUG_INFO(priv, "enter\n"); + if (sta_id == priv->contexts[IWL_RXON_CTX_BSS].bcast_sta_id) + goto out; + + psta = (struct iwl3945_sta_priv *) sta->drv_priv; + rs_sta = &psta->rs_sta; + sband = hw->wiphy->bands[conf->channel->band]; + + rs_sta->priv = priv; + + rs_sta->start_rate = IWL_RATE_INVALID; + + /* default to just 802.11b */ + rs_sta->expected_tpt = iwl3945_expected_tpt_b; + + rs_sta->last_partial_flush = jiffies; + rs_sta->last_flush = jiffies; + rs_sta->flush_time = IWL_RATE_FLUSH; + rs_sta->last_tx_packets = 0; + + rs_sta->rate_scale_flush.data = (unsigned long)rs_sta; + rs_sta->rate_scale_flush.function = iwl3945_bg_rate_scale_flush; + + for (i = 0; i < IWL_RATE_COUNT_3945; i++) + iwl3945_clear_window(&rs_sta->win[i]); + + /* TODO: what is a good starting rate for STA? About middle? Maybe not + * the lowest or the highest rate.. Could consider using RSSI from + * previous packets? Need to have IEEE 802.1X auth succeed immediately + * after assoc.. */ + + for (i = sband->n_bitrates - 1; i >= 0; i--) { + if (sta->supp_rates[sband->band] & (1 << i)) { + rs_sta->last_txrate_idx = i; + break; + } + } + + priv->_3945.sta_supp_rates = sta->supp_rates[sband->band]; + /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */ + if (sband->band == IEEE80211_BAND_5GHZ) { + rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE; + priv->_3945.sta_supp_rates = priv->_3945.sta_supp_rates << + IWL_FIRST_OFDM_RATE; + } + +out: + priv->stations[sta_id].used &= ~IWL_STA_UCODE_INPROGRESS; + + IWL_DEBUG_INFO(priv, "leave\n"); +} + +static void *iwl3945_rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) +{ + return hw->priv; +} + +/* rate scale requires free function to be implemented */ +static void iwl3945_rs_free(void *priv) +{ + return; +} + +static void *iwl3945_rs_alloc_sta(void *iwl_priv, struct ieee80211_sta *sta, gfp_t gfp) +{ + struct iwl3945_rs_sta *rs_sta; + struct iwl3945_sta_priv *psta = (void *) sta->drv_priv; + struct iwl_priv *priv __maybe_unused = iwl_priv; + + IWL_DEBUG_RATE(priv, "enter\n"); + + rs_sta = &psta->rs_sta; + + spin_lock_init(&rs_sta->lock); + init_timer(&rs_sta->rate_scale_flush); + + IWL_DEBUG_RATE(priv, "leave\n"); + + return rs_sta; +} + +static void iwl3945_rs_free_sta(void *iwl_priv, struct ieee80211_sta *sta, + void *priv_sta) +{ + struct iwl3945_rs_sta *rs_sta = priv_sta; + + /* + * Be careful not to use any members of iwl3945_rs_sta (like trying + * to use iwl_priv to print out debugging) since it may not be fully + * initialized at this point. + */ + del_timer_sync(&rs_sta->rate_scale_flush); +} + + +/** + * iwl3945_rs_tx_status - Update rate control values based on Tx results + * + * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by + * the hardware for each rate. + */ +static void iwl3945_rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband, + struct ieee80211_sta *sta, void *priv_sta, + struct sk_buff *skb) +{ + s8 retries = 0, current_count; + int scale_rate_index, first_index, last_index; + unsigned long flags; + struct iwl_priv *priv = (struct iwl_priv *)priv_rate; + struct iwl3945_rs_sta *rs_sta = priv_sta; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + + IWL_DEBUG_RATE(priv, "enter\n"); + + retries = info->status.rates[0].count; + /* Sanity Check for retries */ + if (retries > IWL_RATE_RETRY_TH) + retries = IWL_RATE_RETRY_TH; + + first_index = sband->bitrates[info->status.rates[0].idx].hw_value; + if ((first_index < 0) || (first_index >= IWL_RATE_COUNT_3945)) { + IWL_DEBUG_RATE(priv, "leave: Rate out of bounds: %d\n", first_index); + return; + } + + if (!priv_sta) { + IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n"); + return; + } + + /* Treat uninitialized rate scaling data same as non-existing. */ + if (!rs_sta->priv) { + IWL_DEBUG_RATE(priv, "leave: STA priv data uninitialized!\n"); + return; + } + + + rs_sta->tx_packets++; + + scale_rate_index = first_index; + last_index = first_index; + + /* + * Update the window for each rate. We determine which rates + * were Tx'd based on the total number of retries vs. the number + * of retries configured for each rate -- currently set to the + * priv value 'retry_rate' vs. rate specific + * + * On exit from this while loop last_index indicates the rate + * at which the frame was finally transmitted (or failed if no + * ACK) + */ + while (retries > 1) { + if ((retries - 1) < priv->retry_rate) { + current_count = (retries - 1); + last_index = scale_rate_index; + } else { + current_count = priv->retry_rate; + last_index = iwl3945_rs_next_rate(priv, + scale_rate_index); + } + + /* Update this rate accounting for as many retries + * as was used for it (per current_count) */ + iwl3945_collect_tx_data(rs_sta, + &rs_sta->win[scale_rate_index], + 0, current_count, scale_rate_index); + IWL_DEBUG_RATE(priv, "Update rate %d for %d retries.\n", + scale_rate_index, current_count); + + retries -= current_count; + + scale_rate_index = last_index; + } + + + /* Update the last index window with success/failure based on ACK */ + IWL_DEBUG_RATE(priv, "Update rate %d with %s.\n", + last_index, + (info->flags & IEEE80211_TX_STAT_ACK) ? + "success" : "failure"); + iwl3945_collect_tx_data(rs_sta, + &rs_sta->win[last_index], + info->flags & IEEE80211_TX_STAT_ACK, 1, last_index); + + /* We updated the rate scale window -- if its been more than + * flush_time since the last run, schedule the flush + * again */ + spin_lock_irqsave(&rs_sta->lock, flags); + + if (!rs_sta->flush_pending && + time_after(jiffies, rs_sta->last_flush + + rs_sta->flush_time)) { + + rs_sta->last_partial_flush = jiffies; + rs_sta->flush_pending = 1; + mod_timer(&rs_sta->rate_scale_flush, + jiffies + rs_sta->flush_time); + } + + spin_unlock_irqrestore(&rs_sta->lock, flags); + + IWL_DEBUG_RATE(priv, "leave\n"); +} + +static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta, + u8 index, u16 rate_mask, enum ieee80211_band band) +{ + u8 high = IWL_RATE_INVALID; + u8 low = IWL_RATE_INVALID; + struct iwl_priv *priv __maybe_unused = rs_sta->priv; + + /* 802.11A walks to the next literal adjacent rate in + * the rate table */ + if (unlikely(band == IEEE80211_BAND_5GHZ)) { + int i; + u32 mask; + + /* Find the previous rate that is in the rate mask */ + i = index - 1; + for (mask = (1 << i); i >= 0; i--, mask >>= 1) { + if (rate_mask & mask) { + low = i; + break; + } + } + + /* Find the next rate that is in the rate mask */ + i = index + 1; + for (mask = (1 << i); i < IWL_RATE_COUNT_3945; + i++, mask <<= 1) { + if (rate_mask & mask) { + high = i; + break; + } + } + + return (high << 8) | low; + } + + low = index; + while (low != IWL_RATE_INVALID) { + if (rs_sta->tgg) + low = iwl3945_rates[low].prev_rs_tgg; + else + low = iwl3945_rates[low].prev_rs; + if (low == IWL_RATE_INVALID) + break; + if (rate_mask & (1 << low)) + break; + IWL_DEBUG_RATE(priv, "Skipping masked lower rate: %d\n", low); + } + + high = index; + while (high != IWL_RATE_INVALID) { + if (rs_sta->tgg) + high = iwl3945_rates[high].next_rs_tgg; + else + high = iwl3945_rates[high].next_rs; + if (high == IWL_RATE_INVALID) + break; + if (rate_mask & (1 << high)) + break; + IWL_DEBUG_RATE(priv, "Skipping masked higher rate: %d\n", high); + } + + return (high << 8) | low; +} + +/** + * iwl3945_rs_get_rate - find the rate for the requested packet + * + * Returns the ieee80211_rate structure allocated by the driver. + * + * The rate control algorithm has no internal mapping between hw_mode's + * rate ordering and the rate ordering used by the rate control algorithm. + * + * The rate control algorithm uses a single table of rates that goes across + * the entire A/B/G spectrum vs. being limited to just one particular + * hw_mode. + * + * As such, we can't convert the index obtained below into the hw_mode's + * rate table and must reference the driver allocated rate table + * + */ +static void iwl3945_rs_get_rate(void *priv_r, struct ieee80211_sta *sta, + void *priv_sta, struct ieee80211_tx_rate_control *txrc) +{ + struct ieee80211_supported_band *sband = txrc->sband; + struct sk_buff *skb = txrc->skb; + u8 low = IWL_RATE_INVALID; + u8 high = IWL_RATE_INVALID; + u16 high_low; + int index; + struct iwl3945_rs_sta *rs_sta = priv_sta; + struct iwl3945_rate_scale_data *window = NULL; + int current_tpt = IWL_INVALID_VALUE; + int low_tpt = IWL_INVALID_VALUE; + int high_tpt = IWL_INVALID_VALUE; + u32 fail_count; + s8 scale_action = 0; + unsigned long flags; + u16 rate_mask; + s8 max_rate_idx = -1; + struct iwl_priv *priv __maybe_unused = (struct iwl_priv *)priv_r; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + + IWL_DEBUG_RATE(priv, "enter\n"); + + /* Treat uninitialized rate scaling data same as non-existing. */ + if (rs_sta && !rs_sta->priv) { + IWL_DEBUG_RATE(priv, "Rate scaling information not initialized yet.\n"); + priv_sta = NULL; + } + + if (rate_control_send_low(sta, priv_sta, txrc)) + return; + + rate_mask = sta->supp_rates[sband->band]; + + /* get user max rate if set */ + max_rate_idx = txrc->max_rate_idx; + if ((sband->band == IEEE80211_BAND_5GHZ) && (max_rate_idx != -1)) + max_rate_idx += IWL_FIRST_OFDM_RATE; + if ((max_rate_idx < 0) || (max_rate_idx >= IWL_RATE_COUNT)) + max_rate_idx = -1; + + index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT_3945 - 1); + + if (sband->band == IEEE80211_BAND_5GHZ) + rate_mask = rate_mask << IWL_FIRST_OFDM_RATE; + + spin_lock_irqsave(&rs_sta->lock, flags); + + /* for recent assoc, choose best rate regarding + * to rssi value + */ + if (rs_sta->start_rate != IWL_RATE_INVALID) { + if (rs_sta->start_rate < index && + (rate_mask & (1 << rs_sta->start_rate))) + index = rs_sta->start_rate; + rs_sta->start_rate = IWL_RATE_INVALID; + } + + /* force user max rate if set by user */ + if ((max_rate_idx != -1) && (max_rate_idx < index)) { + if (rate_mask & (1 << max_rate_idx)) + index = max_rate_idx; + } + + window = &(rs_sta->win[index]); + + fail_count = window->counter - window->success_counter; + + if (((fail_count < IWL_RATE_MIN_FAILURE_TH) && + (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) { + spin_unlock_irqrestore(&rs_sta->lock, flags); + + IWL_DEBUG_RATE(priv, "Invalid average_tpt on rate %d: " + "counter: %d, success_counter: %d, " + "expected_tpt is %sNULL\n", + index, + window->counter, + window->success_counter, + rs_sta->expected_tpt ? "not " : ""); + + /* Can't calculate this yet; not enough history */ + window->average_tpt = IWL_INVALID_VALUE; + goto out; + + } + + current_tpt = window->average_tpt; + + high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask, + sband->band); + low = high_low & 0xff; + high = (high_low >> 8) & 0xff; + + /* If user set max rate, dont allow higher than user constrain */ + if ((max_rate_idx != -1) && (max_rate_idx < high)) + high = IWL_RATE_INVALID; + + /* Collect Measured throughputs of adjacent rates */ + if (low != IWL_RATE_INVALID) + low_tpt = rs_sta->win[low].average_tpt; + + if (high != IWL_RATE_INVALID) + high_tpt = rs_sta->win[high].average_tpt; + + spin_unlock_irqrestore(&rs_sta->lock, flags); + + scale_action = 0; + + /* Low success ratio , need to drop the rate */ + if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) { + IWL_DEBUG_RATE(priv, "decrease rate because of low success_ratio\n"); + scale_action = -1; + /* No throughput measured yet for adjacent rates, + * try increase */ + } else if ((low_tpt == IWL_INVALID_VALUE) && + (high_tpt == IWL_INVALID_VALUE)) { + + if (high != IWL_RATE_INVALID && window->success_ratio >= IWL_RATE_INCREASE_TH) + scale_action = 1; + else if (low != IWL_RATE_INVALID) + scale_action = 0; + + /* Both adjacent throughputs are measured, but neither one has + * better throughput; we're using the best rate, don't change + * it! */ + } else if ((low_tpt != IWL_INVALID_VALUE) && + (high_tpt != IWL_INVALID_VALUE) && + (low_tpt < current_tpt) && (high_tpt < current_tpt)) { + + IWL_DEBUG_RATE(priv, "No action -- low [%d] & high [%d] < " + "current_tpt [%d]\n", + low_tpt, high_tpt, current_tpt); + scale_action = 0; + + /* At least one of the rates has better throughput */ + } else { + if (high_tpt != IWL_INVALID_VALUE) { + + /* High rate has better throughput, Increase + * rate */ + if (high_tpt > current_tpt && + window->success_ratio >= IWL_RATE_INCREASE_TH) + scale_action = 1; + else { + IWL_DEBUG_RATE(priv, + "decrease rate because of high tpt\n"); + scale_action = 0; + } + } else if (low_tpt != IWL_INVALID_VALUE) { + if (low_tpt > current_tpt) { + IWL_DEBUG_RATE(priv, + "decrease rate because of low tpt\n"); + scale_action = -1; + } else if (window->success_ratio >= IWL_RATE_INCREASE_TH) { + /* Lower rate has better + * throughput,decrease rate */ + scale_action = 1; + } + } + } + + /* Sanity check; asked for decrease, but success rate or throughput + * has been good at old rate. Don't change it. */ + if ((scale_action == -1) && (low != IWL_RATE_INVALID) && + ((window->success_ratio > IWL_RATE_HIGH_TH) || + (current_tpt > (100 * rs_sta->expected_tpt[low])))) + scale_action = 0; + + switch (scale_action) { + case -1: + + /* Decrese rate */ + if (low != IWL_RATE_INVALID) + index = low; + break; + + case 1: + /* Increase rate */ + if (high != IWL_RATE_INVALID) + index = high; + + break; + + case 0: + default: + /* No change */ + break; + } + + IWL_DEBUG_RATE(priv, "Selected %d (action %d) - low %d high %d\n", + index, scale_action, low, high); + + out: + + rs_sta->last_txrate_idx = index; + if (sband->band == IEEE80211_BAND_5GHZ) + info->control.rates[0].idx = rs_sta->last_txrate_idx - + IWL_FIRST_OFDM_RATE; + else + info->control.rates[0].idx = rs_sta->last_txrate_idx; + + IWL_DEBUG_RATE(priv, "leave: %d\n", index); +} + +#ifdef CONFIG_MAC80211_DEBUGFS +static int iwl3945_open_file_generic(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + return 0; +} + +static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file, + char __user *user_buf, + size_t count, loff_t *ppos) +{ + char *buff; + int desc = 0; + int j; + ssize_t ret; + struct iwl3945_rs_sta *lq_sta = file->private_data; + + buff = kmalloc(1024, GFP_KERNEL); + if (!buff) + return -ENOMEM; + + desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n" + "rate=0x%X flush time %d\n", + lq_sta->tx_packets, + lq_sta->last_txrate_idx, + lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time)); + for (j = 0; j < IWL_RATE_COUNT_3945; j++) { + desc += sprintf(buff+desc, + "counter=%d success=%d %%=%d\n", + lq_sta->win[j].counter, + lq_sta->win[j].success_counter, + lq_sta->win[j].success_ratio); + } + ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc); + kfree(buff); + return ret; +} + +static const struct file_operations rs_sta_dbgfs_stats_table_ops = { + .read = iwl3945_sta_dbgfs_stats_table_read, + .open = iwl3945_open_file_generic, + .llseek = default_llseek, +}; + +static void iwl3945_add_debugfs(void *priv, void *priv_sta, + struct dentry *dir) +{ + struct iwl3945_rs_sta *lq_sta = priv_sta; + + lq_sta->rs_sta_dbgfs_stats_table_file = + debugfs_create_file("rate_stats_table", 0600, dir, + lq_sta, &rs_sta_dbgfs_stats_table_ops); + +} + +static void iwl3945_remove_debugfs(void *priv, void *priv_sta) +{ + struct iwl3945_rs_sta *lq_sta = priv_sta; + debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file); +} +#endif + +/* + * Initialization of rate scaling information is done by driver after + * the station is added. Since mac80211 calls this function before a + * station is added we ignore it. + */ +static void iwl3945_rs_rate_init_stub(void *priv_r, + struct ieee80211_supported_band *sband, + struct ieee80211_sta *sta, void *priv_sta) +{ +} + +static struct rate_control_ops rs_ops = { + .module = NULL, + .name = RS_NAME, + .tx_status = iwl3945_rs_tx_status, + .get_rate = iwl3945_rs_get_rate, + .rate_init = iwl3945_rs_rate_init_stub, + .alloc = iwl3945_rs_alloc, + .free = iwl3945_rs_free, + .alloc_sta = iwl3945_rs_alloc_sta, + .free_sta = iwl3945_rs_free_sta, +#ifdef CONFIG_MAC80211_DEBUGFS + .add_sta_debugfs = iwl3945_add_debugfs, + .remove_sta_debugfs = iwl3945_remove_debugfs, +#endif + +}; +void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id) +{ + struct iwl_priv *priv = hw->priv; + s32 rssi = 0; + unsigned long flags; + struct iwl3945_rs_sta *rs_sta; + struct ieee80211_sta *sta; + struct iwl3945_sta_priv *psta; + + IWL_DEBUG_RATE(priv, "enter\n"); + + rcu_read_lock(); + + sta = ieee80211_find_sta(priv->contexts[IWL_RXON_CTX_BSS].vif, + priv->stations[sta_id].sta.sta.addr); + if (!sta) { + IWL_DEBUG_RATE(priv, "Unable to find station to initialize rate scaling.\n"); + rcu_read_unlock(); + return; + } + + psta = (void *) sta->drv_priv; + rs_sta = &psta->rs_sta; + + spin_lock_irqsave(&rs_sta->lock, flags); + + rs_sta->tgg = 0; + switch (priv->band) { + case IEEE80211_BAND_2GHZ: + /* TODO: this always does G, not a regression */ + if (priv->contexts[IWL_RXON_CTX_BSS].active.flags & + RXON_FLG_TGG_PROTECT_MSK) { + rs_sta->tgg = 1; + rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot; + } else + rs_sta->expected_tpt = iwl3945_expected_tpt_g; + break; + + case IEEE80211_BAND_5GHZ: + rs_sta->expected_tpt = iwl3945_expected_tpt_a; + break; + case IEEE80211_NUM_BANDS: + BUG(); + break; + } + + spin_unlock_irqrestore(&rs_sta->lock, flags); + + rssi = priv->_3945.last_rx_rssi; + if (rssi == 0) + rssi = IWL_MIN_RSSI_VAL; + + IWL_DEBUG_RATE(priv, "Network RSSI: %d\n", rssi); + + rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band); + + IWL_DEBUG_RATE(priv, "leave: rssi %d assign rate index: " + "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate, + iwl3945_rates[rs_sta->start_rate].plcp); + rcu_read_unlock(); +} + +int iwl3945_rate_control_register(void) +{ + return ieee80211_rate_control_register(&rs_ops); +} + +void iwl3945_rate_control_unregister(void) +{ + ieee80211_rate_control_unregister(&rs_ops); +} |