1 files changed, 979 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlegacy/3945-rs.c b/drivers/net/wireless/intel/iwlegacy/3945-rs.c
new file mode 100644
index 000000000000..76b0729ade17
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlegacy/3945-rs.c
@@ -0,0 +1,979 @@
+/******************************************************************************
+ *
+ * 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/skbuff.h>
+#include <linux/slab.h>
+#include <net/mac80211.h>
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/delay.h>
+
+#include <linux/workqueue.h>
+
+#include "commands.h"
+#include "3945.h"
+
+#define RS_NAME "iwl-3945-rs"
+
+static s32 il3945_expected_tpt_g[RATE_COUNT_3945] = {
+        7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
+};
+
+static s32 il3945_expected_tpt_g_prot[RATE_COUNT_3945] = {
+        7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
+};
+
+static s32 il3945_expected_tpt_a[RATE_COUNT_3945] = {
+        0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
+};
+
+static s32 il3945_expected_tpt_b[RATE_COUNT_3945] = {
+        7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+struct il3945_tpt_entry {
+        s8 min_rssi;
+        u8 idx;
+};
+
+static struct il3945_tpt_entry il3945_tpt_table_a[] = {
+        {-60, RATE_54M_IDX},
+        {-64, RATE_48M_IDX},
+        {-72, RATE_36M_IDX},
+        {-80, RATE_24M_IDX},
+        {-84, RATE_18M_IDX},
+        {-85, RATE_12M_IDX},
+        {-87, RATE_9M_IDX},
+        {-89, RATE_6M_IDX}
+};
+
+static struct il3945_tpt_entry il3945_tpt_table_g[] = {
+        {-60, RATE_54M_IDX},
+        {-64, RATE_48M_IDX},
+        {-68, RATE_36M_IDX},
+        {-80, RATE_24M_IDX},
+        {-84, RATE_18M_IDX},
+        {-85, RATE_12M_IDX},
+        {-86, RATE_11M_IDX},
+        {-88, RATE_5M_IDX},
+        {-90, RATE_2M_IDX},
+        {-92, RATE_1M_IDX}
+};
+
+#define RATE_MAX_WINDOW         62
+#define RATE_FLUSH              (3*HZ)
+#define RATE_WIN_FLUSH          (HZ/2)
+#define IL39_RATE_HIGH_TH       11520
+#define IL_SUCCESS_UP_TH        8960
+#define IL_SUCCESS_DOWN_TH      10880
+#define RATE_MIN_FAILURE_TH     6
+#define RATE_MIN_SUCCESS_TH     8
+#define RATE_DECREASE_TH        1920
+#define RATE_RETRY_TH           15
+
+static u8
+il3945_get_rate_idx_by_rssi(s32 rssi, enum ieee80211_band band)
+{
+        u32 idx = 0;
+        u32 table_size = 0;
+        struct il3945_tpt_entry *tpt_table = NULL;
+
+        if (rssi < IL_MIN_RSSI_VAL || rssi > IL_MAX_RSSI_VAL)
+                rssi = IL_MIN_RSSI_VAL;
+
+        switch (band) {
+        case IEEE80211_BAND_2GHZ:
+                tpt_table = il3945_tpt_table_g;
+                table_size = ARRAY_SIZE(il3945_tpt_table_g);
+                break;
+        case IEEE80211_BAND_5GHZ:
+                tpt_table = il3945_tpt_table_a;
+                table_size = ARRAY_SIZE(il3945_tpt_table_a);
+                break;
+        default:
+                BUG();
+                break;
+        }
+
+        while (idx < table_size && rssi < tpt_table[idx].min_rssi)
+                idx++;
+
+        idx = min(idx, table_size - 1);
+
+        return tpt_table[idx].idx;
+}
+
+static void
+il3945_clear_win(struct il3945_rate_scale_data *win)
+{
+        win->data = 0;
+        win->success_counter = 0;
+        win->success_ratio = -1;
+        win->counter = 0;
+        win->average_tpt = IL_INVALID_VALUE;
+        win->stamp = 0;
+}
+
+/**
+ * il3945_rate_scale_flush_wins - flush out the rate scale wins
+ *
+ * Returns the number of wins that have gathered data but were
+ * not flushed.  If there were any that were not flushed, then
+ * reschedule the rate flushing routine.
+ */
+static int
+il3945_rate_scale_flush_wins(struct il3945_rs_sta *rs_sta)
+{
+        int unflushed = 0;
+        int i;
+        unsigned long flags;
+        struct il_priv *il __maybe_unused = rs_sta->il;
+
+        /*
+         * For each rate, if we have collected data on that rate
+         * and it has been more than RATE_WIN_FLUSH
+         * since we flushed, clear out the gathered stats
+         */
+        for (i = 0; i < 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 + RATE_WIN_FLUSH)) {
+                        D_RATE("flushing %d samples of rate " "idx %d\n",
+                               rs_sta->win[i].counter, i);
+                        il3945_clear_win(&rs_sta->win[i]);
+                } else
+                        unflushed++;
+                spin_unlock_irqrestore(&rs_sta->lock, flags);
+        }
+
+        return unflushed;
+}
+
+#define RATE_FLUSH_MAX              5000        /* msec */
+#define RATE_FLUSH_MIN              50  /* msec */
+#define IL_AVERAGE_PACKETS             1500
+
+static void
+il3945_bg_rate_scale_flush(unsigned long data)
+{
+        struct il3945_rs_sta *rs_sta = (void *)data;
+        struct il_priv *il __maybe_unused = rs_sta->il;
+        int unflushed = 0;
+        unsigned long flags;
+        u32 packet_count, duration, pps;
+
+        D_RATE("enter\n");
+
+        unflushed = il3945_rate_scale_flush_wins(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);
+
+                D_RATE("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 = (IL_AVERAGE_PACKETS * 1000) / pps;
+                        if (duration < RATE_FLUSH_MIN)
+                                duration = RATE_FLUSH_MIN;
+                        else if (duration > RATE_FLUSH_MAX)
+                                duration = RATE_FLUSH_MAX;
+                } else
+                        duration = RATE_FLUSH_MAX;
+
+                rs_sta->flush_time = msecs_to_jiffies(duration);
+
+                D_RATE("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 = 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);
+
+        D_RATE("leave\n");
+}
+
+/**
+ * il3945_collect_tx_data - Update the success/failure sliding win
+ *
+ * We keep a sliding win of the last 64 packets transmitted
+ * at this rate.  win->data contains the bitmask of successful
+ * packets.
+ */
+static void
+il3945_collect_tx_data(struct il3945_rs_sta *rs_sta,
+                       struct il3945_rate_scale_data *win, int success,
+                       int retries, int idx)
+{
+        unsigned long flags;
+        s32 fail_count;
+        struct il_priv *il __maybe_unused = rs_sta->il;
+
+        if (!retries) {
+                D_RATE("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 win; anything older isn't really relevant any more.
+         * If we have filled up the sliding win, 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 (win->counter >= RATE_MAX_WINDOW) {
+
+                        /* remove earliest */
+                        win->counter = RATE_MAX_WINDOW - 1;
+
+                        if (win->data & (1ULL << (RATE_MAX_WINDOW - 1))) {
+                                win->data &= ~(1ULL << (RATE_MAX_WINDOW - 1));
+                                win->success_counter--;
+                        }
+                }
+
+                /* Increment frames-attempted counter */
+                win->counter++;
+
+                /* Shift bitmap by one frame (throw away oldest history),
+                 * OR in "1", and increment "success" if this
+                 * frame was successful. */
+                win->data <<= 1;
+                if (success > 0) {
+                        win->success_counter++;
+                        win->data |= 0x1;
+                        success--;
+                }
+
+                retries--;
+        }
+
+        /* Calculate current success ratio, avoid divide-by-0! */
+        if (win->counter > 0)
+                win->success_ratio =
+                    128 * (100 * win->success_counter) / win->counter;
+        else
+                win->success_ratio = IL_INVALID_VALUE;
+
+        fail_count = win->counter - win->success_counter;
+
+        /* Calculate average throughput, if we have enough history. */
+        if (fail_count >= RATE_MIN_FAILURE_TH ||
+            win->success_counter >= RATE_MIN_SUCCESS_TH)
+                win->average_tpt =
+                    ((win->success_ratio * rs_sta->expected_tpt[idx] +
+                      64) / 128);
+        else
+                win->average_tpt = IL_INVALID_VALUE;
+
+        /* Tag this win as having been updated */
+        win->stamp = jiffies;
+
+        spin_unlock_irqrestore(&rs_sta->lock, flags);
+}
+
+/*
+ * Called after adding a new station to initialize rate scaling
+ */
+void
+il3945_rs_rate_init(struct il_priv *il, struct ieee80211_sta *sta, u8 sta_id)
+{
+        struct ieee80211_hw *hw = il->hw;
+        struct ieee80211_conf *conf = &il->hw->conf;
+        struct il3945_sta_priv *psta;
+        struct il3945_rs_sta *rs_sta;
+        struct ieee80211_supported_band *sband;
+        int i;
+
+        D_INFO("enter\n");
+        if (sta_id == il->hw_params.bcast_id)
+                goto out;
+
+        psta = (struct il3945_sta_priv *)sta->drv_priv;
+        rs_sta = &psta->rs_sta;
+        sband = hw->wiphy->bands[conf->chandef.chan->band];
+
+        rs_sta->il = il;
+
+        rs_sta->start_rate = RATE_INVALID;
+
+        /* default to just 802.11b */
+        rs_sta->expected_tpt = il3945_expected_tpt_b;
+
+        rs_sta->last_partial_flush = jiffies;
+        rs_sta->last_flush = jiffies;
+        rs_sta->flush_time = RATE_FLUSH;
+        rs_sta->last_tx_packets = 0;
+
+        rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
+        rs_sta->rate_scale_flush.function = il3945_bg_rate_scale_flush;
+
+        for (i = 0; i < RATE_COUNT_3945; i++)
+                il3945_clear_win(&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;
+                }
+        }
+
+        il->_3945.sta_supp_rates = sta->supp_rates[sband->band];
+        /* For 5 GHz band it start at IL_FIRST_OFDM_RATE */
+        if (sband->band == IEEE80211_BAND_5GHZ) {
+                rs_sta->last_txrate_idx += IL_FIRST_OFDM_RATE;
+                il->_3945.sta_supp_rates <<= IL_FIRST_OFDM_RATE;
+        }
+
+out:
+        il->stations[sta_id].used &= ~IL_STA_UCODE_INPROGRESS;
+
+        D_INFO("leave\n");
+}
+
+static void *
+il3945_rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
+{
+        return hw->priv;
+}
+
+/* rate scale requires free function to be implemented */
+static void
+il3945_rs_free(void *il)
+{
+}
+
+static void *
+il3945_rs_alloc_sta(void *il_priv, struct ieee80211_sta *sta, gfp_t gfp)
+{
+        struct il3945_rs_sta *rs_sta;
+        struct il3945_sta_priv *psta = (void *)sta->drv_priv;
+        struct il_priv *il __maybe_unused = il_priv;
+
+        D_RATE("enter\n");
+
+        rs_sta = &psta->rs_sta;
+
+        spin_lock_init(&rs_sta->lock);
+        init_timer(&rs_sta->rate_scale_flush);
+
+        D_RATE("leave\n");
+
+        return rs_sta;
+}
+
+static void
+il3945_rs_free_sta(void *il_priv, struct ieee80211_sta *sta, void *il_sta)
+{
+        struct il3945_rs_sta *rs_sta = il_sta;
+
+        /*
+         * Be careful not to use any members of il3945_rs_sta (like trying
+         * to use il_priv to print out debugging) since it may not be fully
+         * initialized at this point.
+         */
+        del_timer_sync(&rs_sta->rate_scale_flush);
+}
+
+/**
+ * il3945_rs_tx_status - Update rate control values based on Tx results
+ *
+ * NOTE: Uses il_priv->retry_rate for the # of retries attempted by
+ * the hardware for each rate.
+ */
+static void
+il3945_rs_tx_status(void *il_rate, struct ieee80211_supported_band *sband,
+                    struct ieee80211_sta *sta, void *il_sta,
+                    struct sk_buff *skb)
+{
+        s8 retries = 0, current_count;
+        int scale_rate_idx, first_idx, last_idx;
+        unsigned long flags;
+        struct il_priv *il = (struct il_priv *)il_rate;
+        struct il3945_rs_sta *rs_sta = il_sta;
+        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+
+        D_RATE("enter\n");
+
+        retries = info->status.rates[0].count;
+        /* Sanity Check for retries */
+        if (retries > RATE_RETRY_TH)
+                retries = RATE_RETRY_TH;
+
+        first_idx = sband->bitrates[info->status.rates[0].idx].hw_value;
+        if (first_idx < 0 || first_idx >= RATE_COUNT_3945) {
+                D_RATE("leave: Rate out of bounds: %d\n", first_idx);
+                return;
+        }
+
+        if (!il_sta) {
+                D_RATE("leave: No STA il data to update!\n");
+                return;
+        }
+
+        /* Treat uninitialized rate scaling data same as non-existing. */
+        if (!rs_sta->il) {
+                D_RATE("leave: STA il data uninitialized!\n");
+                return;
+        }
+
+        rs_sta->tx_packets++;
+
+        scale_rate_idx = first_idx;
+        last_idx = first_idx;
+
+        /*
+         * Update the win 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
+         * il value 'retry_rate' vs. rate specific
+         *
+         * On exit from this while loop last_idx indicates the rate
+         * at which the frame was finally transmitted (or failed if no
+         * ACK)
+         */
+        while (retries > 1) {
+                if ((retries - 1) < il->retry_rate) {
+                        current_count = (retries - 1);
+                        last_idx = scale_rate_idx;
+                } else {
+                        current_count = il->retry_rate;
+                        last_idx = il3945_rs_next_rate(il, scale_rate_idx);
+                }
+
+                /* Update this rate accounting for as many retries
+                 * as was used for it (per current_count) */
+                il3945_collect_tx_data(rs_sta, &rs_sta->win[scale_rate_idx], 0,
+                                       current_count, scale_rate_idx);
+                D_RATE("Update rate %d for %d retries.\n", scale_rate_idx,
+                       current_count);
+
+                retries -= current_count;
+
+                scale_rate_idx = last_idx;
+        }
+
+        /* Update the last idx win with success/failure based on ACK */
+        D_RATE("Update rate %d with %s.\n", last_idx,
+               (info->flags & IEEE80211_TX_STAT_ACK) ? "success" : "failure");
+        il3945_collect_tx_data(rs_sta, &rs_sta->win[last_idx],
+                               info->flags & IEEE80211_TX_STAT_ACK, 1,
+                               last_idx);
+
+        /* We updated the rate scale win -- 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);
+
+        D_RATE("leave\n");
+}
+
+static u16
+il3945_get_adjacent_rate(struct il3945_rs_sta *rs_sta, u8 idx, u16 rate_mask,
+                         enum ieee80211_band band)
+{
+        u8 high = RATE_INVALID;
+        u8 low = RATE_INVALID;
+        struct il_priv *il __maybe_unused = rs_sta->il;
+
+        /* 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 = idx - 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 = idx + 1;
+                for (mask = (1 << i); i < RATE_COUNT_3945; i++, mask <<= 1) {
+                        if (rate_mask & mask) {
+                                high = i;
+                                break;
+                        }
+                }
+
+                return (high << 8) | low;
+        }
+
+        low = idx;
+        while (low != RATE_INVALID) {
+                if (rs_sta->tgg)
+                        low = il3945_rates[low].prev_rs_tgg;
+                else
+                        low = il3945_rates[low].prev_rs;
+                if (low == RATE_INVALID)
+                        break;
+                if (rate_mask & (1 << low))
+                        break;
+                D_RATE("Skipping masked lower rate: %d\n", low);
+        }
+
+        high = idx;
+        while (high != RATE_INVALID) {
+                if (rs_sta->tgg)
+                        high = il3945_rates[high].next_rs_tgg;
+                else
+                        high = il3945_rates[high].next_rs;
+                if (high == RATE_INVALID)
+                        break;
+                if (rate_mask & (1 << high))
+                        break;
+                D_RATE("Skipping masked higher rate: %d\n", high);
+        }
+
+        return (high << 8) | low;
+}
+
+/**
+ * il3945_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 idx obtained below into the hw_mode's
+ * rate table and must reference the driver allocated rate table
+ *
+ */
+static void
+il3945_rs_get_rate(void *il_r, struct ieee80211_sta *sta, void *il_sta,
+                   struct ieee80211_tx_rate_control *txrc)
+{
+        struct ieee80211_supported_band *sband = txrc->sband;
+        struct sk_buff *skb = txrc->skb;
+        u8 low = RATE_INVALID;
+        u8 high = RATE_INVALID;
+        u16 high_low;
+        int idx;
+        struct il3945_rs_sta *rs_sta = il_sta;
+        struct il3945_rate_scale_data *win = NULL;
+        int current_tpt = IL_INVALID_VALUE;
+        int low_tpt = IL_INVALID_VALUE;
+        int high_tpt = IL_INVALID_VALUE;
+        u32 fail_count;
+        s8 scale_action = 0;
+        unsigned long flags;
+        u16 rate_mask;
+        s8 max_rate_idx = -1;
+        struct il_priv *il __maybe_unused = (struct il_priv *)il_r;
+        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+
+        D_RATE("enter\n");
+
+        /* Treat uninitialized rate scaling data same as non-existing. */
+        if (rs_sta && !rs_sta->il) {
+                D_RATE("Rate scaling information not initialized yet.\n");
+                il_sta = NULL;
+        }
+
+        if (rate_control_send_low(sta, il_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 += IL_FIRST_OFDM_RATE;
+        if (max_rate_idx < 0 || max_rate_idx >= RATE_COUNT)
+                max_rate_idx = -1;
+
+        idx = min(rs_sta->last_txrate_idx & 0xffff, RATE_COUNT_3945 - 1);
+
+        if (sband->band == IEEE80211_BAND_5GHZ)
+                rate_mask = rate_mask << IL_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 != RATE_INVALID) {
+                if (rs_sta->start_rate < idx &&
+                    (rate_mask & (1 << rs_sta->start_rate)))
+                        idx = rs_sta->start_rate;
+                rs_sta->start_rate = RATE_INVALID;
+        }
+
+        /* force user max rate if set by user */
+        if (max_rate_idx != -1 && max_rate_idx < idx) {
+                if (rate_mask & (1 << max_rate_idx))
+                        idx = max_rate_idx;
+        }
+
+        win = &(rs_sta->win[idx]);
+
+        fail_count = win->counter - win->success_counter;
+
+        if (fail_count < RATE_MIN_FAILURE_TH &&
+            win->success_counter < RATE_MIN_SUCCESS_TH) {
+                spin_unlock_irqrestore(&rs_sta->lock, flags);
+
+                D_RATE("Invalid average_tpt on rate %d: "
+                       "counter: %d, success_counter: %d, "
+                       "expected_tpt is %sNULL\n", idx, win->counter,
+                       win->success_counter,
+                       rs_sta->expected_tpt ? "not " : "");
+
+                /* Can't calculate this yet; not enough history */
+                win->average_tpt = IL_INVALID_VALUE;
+                goto out;
+
+        }
+
+        current_tpt = win->average_tpt;
+
+        high_low =
+            il3945_get_adjacent_rate(rs_sta, idx, 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 = RATE_INVALID;
+
+        /* Collect Measured throughputs of adjacent rates */
+        if (low != RATE_INVALID)
+                low_tpt = rs_sta->win[low].average_tpt;
+
+        if (high != 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 (win->success_ratio < RATE_DECREASE_TH || !current_tpt) {
+                D_RATE("decrease rate because of low success_ratio\n");
+                scale_action = -1;
+                /* No throughput measured yet for adjacent rates,
+                 * try increase */
+        } else if (low_tpt == IL_INVALID_VALUE && high_tpt == IL_INVALID_VALUE) {
+
+                if (high != RATE_INVALID &&
+                    win->success_ratio >= RATE_INCREASE_TH)
+                        scale_action = 1;
+                else if (low != 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 != IL_INVALID_VALUE && high_tpt != IL_INVALID_VALUE
+                   && low_tpt < current_tpt && high_tpt < current_tpt) {
+
+                D_RATE("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 != IL_INVALID_VALUE) {
+
+                        /* High rate has better throughput, Increase
+                         * rate */
+                        if (high_tpt > current_tpt &&
+                            win->success_ratio >= RATE_INCREASE_TH)
+                                scale_action = 1;
+                        else {
+                                D_RATE("decrease rate because of high tpt\n");
+                                scale_action = 0;
+                        }
+                } else if (low_tpt != IL_INVALID_VALUE) {
+                        if (low_tpt > current_tpt) {
+                                D_RATE("decrease rate because of low tpt\n");
+                                scale_action = -1;
+                        } else if (win->success_ratio >= 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 != RATE_INVALID &&
+            (win->success_ratio > RATE_HIGH_TH ||
+             current_tpt > 100 * rs_sta->expected_tpt[low]))
+                scale_action = 0;
+
+        switch (scale_action) {
+        case -1:
+                /* Decrese rate */
+                if (low != RATE_INVALID)
+                        idx = low;
+                break;
+        case 1:
+                /* Increase rate */
+                if (high != RATE_INVALID)
+                        idx = high;
+
+                break;
+        case 0:
+        default:
+                /* No change */
+                break;
+        }
+
+        D_RATE("Selected %d (action %d) - low %d high %d\n", idx, scale_action,
+               low, high);
+
+out:
+
+        if (sband->band == IEEE80211_BAND_5GHZ) {
+                if (WARN_ON_ONCE(idx < IL_FIRST_OFDM_RATE))
+                        idx = IL_FIRST_OFDM_RATE;
+                rs_sta->last_txrate_idx = idx;
+                info->control.rates[0].idx = idx - IL_FIRST_OFDM_RATE;
+        } else {
+                rs_sta->last_txrate_idx = idx;
+                info->control.rates[0].idx = rs_sta->last_txrate_idx;
+        }
+        info->control.rates[0].count = 1;
+
+        D_RATE("leave: %d\n", idx);
+}
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+
+static ssize_t
+il3945_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 il3945_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 idx=%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 < 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 = il3945_sta_dbgfs_stats_table_read,
+        .open = simple_open,
+        .llseek = default_llseek,
+};
+
+static void
+il3945_add_debugfs(void *il, void *il_sta, struct dentry *dir)
+{
+        struct il3945_rs_sta *lq_sta = il_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
+il3945_remove_debugfs(void *il, void *il_sta)
+{
+        struct il3945_rs_sta *lq_sta = il_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
+il3945_rs_rate_init_stub(void *il_r, struct ieee80211_supported_band *sband,
+                         struct cfg80211_chan_def *chandef,
+                         struct ieee80211_sta *sta, void *il_sta)
+{
+}
+
+static const struct rate_control_ops rs_ops = {
+        .name = RS_NAME,
+        .tx_status = il3945_rs_tx_status,
+        .get_rate = il3945_rs_get_rate,
+        .rate_init = il3945_rs_rate_init_stub,
+        .alloc = il3945_rs_alloc,
+        .free = il3945_rs_free,
+        .alloc_sta = il3945_rs_alloc_sta,
+        .free_sta = il3945_rs_free_sta,
+#ifdef CONFIG_MAC80211_DEBUGFS
+        .add_sta_debugfs = il3945_add_debugfs,
+        .remove_sta_debugfs = il3945_remove_debugfs,
+#endif
+
+};
+
+void
+il3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
+{
+        struct il_priv *il = hw->priv;
+        s32 rssi = 0;
+        unsigned long flags;
+        struct il3945_rs_sta *rs_sta;
+        struct ieee80211_sta *sta;
+        struct il3945_sta_priv *psta;
+
+        D_RATE("enter\n");
+
+        rcu_read_lock();
+
+        sta = ieee80211_find_sta(il->vif, il->stations[sta_id].sta.sta.addr);
+        if (!sta) {
+                D_RATE("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 (il->band) {
+        case IEEE80211_BAND_2GHZ:
+                /* TODO: this always does G, not a regression */
+                if (il->active.flags & RXON_FLG_TGG_PROTECT_MSK) {
+                        rs_sta->tgg = 1;
+                        rs_sta->expected_tpt = il3945_expected_tpt_g_prot;
+                } else
+                        rs_sta->expected_tpt = il3945_expected_tpt_g;
+                break;
+        case IEEE80211_BAND_5GHZ:
+                rs_sta->expected_tpt = il3945_expected_tpt_a;
+                break;
+        default:
+                BUG();
+                break;
+        }
+
+        spin_unlock_irqrestore(&rs_sta->lock, flags);
+
+        rssi = il->_3945.last_rx_rssi;
+        if (rssi == 0)
+                rssi = IL_MIN_RSSI_VAL;
+
+        D_RATE("Network RSSI: %d\n", rssi);
+
+        rs_sta->start_rate = il3945_get_rate_idx_by_rssi(rssi, il->band);
+
+        D_RATE("leave: rssi %d assign rate idx: " "%d (plcp 0x%x)\n", rssi,
+               rs_sta->start_rate, il3945_rates[rs_sta->start_rate].plcp);
+        rcu_read_unlock();
+}
+
+int
+il3945_rate_control_register(void)
+{
+        return ieee80211_rate_control_register(&rs_ops);
+}
+
+void
+il3945_rate_control_unregister(void)
+{
+        ieee80211_rate_control_unregister(&rs_ops);
+}