text: /******************************************************************************
   *
   * 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 <net/mac80211.h>
  
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/delay.h>
  
  #include <linux/workqueue.h>
  
  #include "iwl-dev.h"
  #include "iwl-core.h"
  #include "iwl-agn.h"
  
  #define RS_NAME "iwl-agn-rs"
  
  #define NUM_TRY_BEFORE_ANT_TOGGLE 1
  #define IWL_NUMBER_TRY      1
  #define IWL_HT_NUMBER_TRY   3
  
  #define IWL_RATE_MAX_WINDOW		62	/* # tx in history window */
  #define IWL_RATE_MIN_FAILURE_TH		6	/* min failures to calc tpt */
  #define IWL_RATE_MIN_SUCCESS_TH		8	/* min successes to calc tpt */
  
  /* max allowed rate miss before sync LQ cmd */
  #define IWL_MISSED_RATE_MAX		15
  /* max time to accum history 2 seconds */
  #define IWL_RATE_SCALE_FLUSH_INTVL   (3*HZ)
  
  static u8 rs_ht_to_legacy[] = {
  	IWL_RATE_6M_INDEX, IWL_RATE_6M_INDEX,
  	IWL_RATE_6M_INDEX, IWL_RATE_6M_INDEX,
  	IWL_RATE_6M_INDEX,
  	IWL_RATE_6M_INDEX, IWL_RATE_9M_INDEX,
  	IWL_RATE_12M_INDEX, IWL_RATE_18M_INDEX,
  	IWL_RATE_24M_INDEX, IWL_RATE_36M_INDEX,
  	IWL_RATE_48M_INDEX, IWL_RATE_54M_INDEX
  };
  
  static const u8 ant_toggle_lookup[] = {
  	/*ANT_NONE -> */ ANT_NONE,
  	/*ANT_A    -> */ ANT_B,
  	/*ANT_B    -> */ ANT_C,
  	/*ANT_AB   -> */ ANT_BC,
  	/*ANT_C    -> */ ANT_A,
  	/*ANT_AC   -> */ ANT_AB,
  	/*ANT_BC   -> */ ANT_AC,
  	/*ANT_ABC  -> */ ANT_ABC,
  };
  
  #define IWL_DECLARE_RATE_INFO(r, s, ip, in, rp, rn, pp, np)    \
  	[IWL_RATE_##r##M_INDEX] = { IWL_RATE_##r##M_PLCP,      \
  				    IWL_RATE_SISO_##s##M_PLCP, \
  				    IWL_RATE_MIMO2_##s##M_PLCP,\
  				    IWL_RATE_MIMO3_##s##M_PLCP,\
  				    IWL_RATE_##r##M_IEEE,      \
  				    IWL_RATE_##ip##M_INDEX,    \
  				    IWL_RATE_##in##M_INDEX,    \
  				    IWL_RATE_##rp##M_INDEX,    \
  				    IWL_RATE_##rn##M_INDEX,    \
  				    IWL_RATE_##pp##M_INDEX,    \
  				    IWL_RATE_##np##M_INDEX }
  
  /*
   * Parameter order:
   *   rate, ht rate, prev rate, next rate, prev tgg rate, next tgg rate
   *
   * If there isn't a valid next or previous rate then INV is used which
   * maps to IWL_RATE_INVALID
   *
   */
  const struct iwl_rate_info iwl_rates[IWL_RATE_COUNT] = {
  	IWL_DECLARE_RATE_INFO(1, INV, INV, 2, INV, 2, INV, 2),    /*  1mbps */
  	IWL_DECLARE_RATE_INFO(2, INV, 1, 5, 1, 5, 1, 5),          /*  2mbps */
  	IWL_DECLARE_RATE_INFO(5, INV, 2, 6, 2, 11, 2, 11),        /*5.5mbps */
  	IWL_DECLARE_RATE_INFO(11, INV, 9, 12, 9, 12, 5, 18),      /* 11mbps */
  	IWL_DECLARE_RATE_INFO(6, 6, 5, 9, 5, 11, 5, 11),        /*  6mbps */
  	IWL_DECLARE_RATE_INFO(9, 6, 6, 11, 6, 11, 5, 11),       /*  9mbps */
  	IWL_DECLARE_RATE_INFO(12, 12, 11, 18, 11, 18, 11, 18),   /* 12mbps */
  	IWL_DECLARE_RATE_INFO(18, 18, 12, 24, 12, 24, 11, 24),   /* 18mbps */
  	IWL_DECLARE_RATE_INFO(24, 24, 18, 36, 18, 36, 18, 36),   /* 24mbps */
  	IWL_DECLARE_RATE_INFO(36, 36, 24, 48, 24, 48, 24, 48),   /* 36mbps */
  	IWL_DECLARE_RATE_INFO(48, 48, 36, 54, 36, 54, 36, 54),   /* 48mbps */
  	IWL_DECLARE_RATE_INFO(54, 54, 48, INV, 48, INV, 48, INV),/* 54mbps */
  	IWL_DECLARE_RATE_INFO(60, 60, 48, INV, 48, INV, 48, INV),/* 60mbps */
  	/* FIXME:RS:          ^^    should be INV (legacy) */
  };
  
  static inline u8 rs_extract_rate(u32 rate_n_flags)
  {
  	return (u8)(rate_n_flags & RATE_MCS_RATE_MSK);
  }
  
  static int iwl_hwrate_to_plcp_idx(u32 rate_n_flags)
  {
  	int idx = 0;
  
  	/* HT rate format */
  	if (rate_n_flags & RATE_MCS_HT_MSK) {
  		idx = rs_extract_rate(rate_n_flags);
  
  		if (idx >= IWL_RATE_MIMO3_6M_PLCP)
  			idx = idx - IWL_RATE_MIMO3_6M_PLCP;
  		else if (idx >= IWL_RATE_MIMO2_6M_PLCP)
  			idx = idx - IWL_RATE_MIMO2_6M_PLCP;
  
  		idx += IWL_FIRST_OFDM_RATE;
  		/* skip 9M not supported in ht*/
  		if (idx >= IWL_RATE_9M_INDEX)
  			idx += 1;
  		if ((idx >= IWL_FIRST_OFDM_RATE) && (idx <= IWL_LAST_OFDM_RATE))
  			return idx;
  
  	/* legacy rate format, search for match in table */
  	} else {
  		for (idx = 0; idx < ARRAY_SIZE(iwl_rates); idx++)
  			if (iwl_rates[idx].plcp ==
  					rs_extract_rate(rate_n_flags))
  				return idx;
  	}
  
  	return -1;
  }
  
  static void rs_rate_scale_perform(struct iwl_priv *priv,
  				   struct sk_buff *skb,
  				   struct ieee80211_sta *sta,
  				   struct iwl_lq_sta *lq_sta);
  static void rs_fill_link_cmd(struct iwl_priv *priv,
  			     struct iwl_lq_sta *lq_sta, u32 rate_n_flags);
  static void rs_stay_in_table(struct iwl_lq_sta *lq_sta, bool force_search);
  
  
  #ifdef CONFIG_MAC80211_DEBUGFS
  static void rs_dbgfs_set_mcs(struct iwl_lq_sta *lq_sta,
  			     u32 *rate_n_flags, int index);
  #else
  static void rs_dbgfs_set_mcs(struct iwl_lq_sta *lq_sta,
  			     u32 *rate_n_flags, int index)
  {}
  #endif
  
  /**
   * The following tables contain the expected throughput metrics for all rates
   *
   *	1, 2, 5.5, 11, 6, 9, 12, 18, 24, 36, 48, 54, 60 MBits
   *
   * where invalid entries are zeros.
   *
   * CCK rates are only valid in legacy table and will only be used in G
   * (2.4 GHz) band.
   */
  
  static s32 expected_tpt_legacy[IWL_RATE_COUNT] = {
  	7, 13, 35, 58, 40, 57, 72, 98, 121, 154, 177, 186, 0
  };
  
  static s32 expected_tpt_siso20MHz[4][IWL_RATE_COUNT] = {
  	{0, 0, 0, 0, 42, 0,  76, 102, 124, 159, 183, 193, 202}, /* Norm */
  	{0, 0, 0, 0, 46, 0,  82, 110, 132, 168, 192, 202, 210}, /* SGI */
  	{0, 0, 0, 0, 47, 0,  91, 133, 171, 242, 305, 334, 362}, /* AGG */
  	{0, 0, 0, 0, 52, 0, 101, 145, 187, 264, 330, 361, 390}, /* AGG+SGI */
  };
  
  static s32 expected_tpt_siso40MHz[4][IWL_RATE_COUNT] = {
  	{0, 0, 0, 0,  77, 0, 127, 160, 184, 220, 242, 250, 257}, /* Norm */
  	{0, 0, 0, 0,  83, 0, 135, 169, 193, 229, 250, 257, 264}, /* SGI */
  	{0, 0, 0, 0,  94, 0, 177, 249, 313, 423, 512, 550, 586}, /* AGG */
  	{0, 0, 0, 0, 104, 0, 193, 270, 338, 454, 545, 584, 620}, /* AGG+SGI */
  };
  
  static s32 expected_tpt_mimo2_20MHz[4][IWL_RATE_COUNT] = {
  	{0, 0, 0, 0,  74, 0, 123, 155, 179, 214, 236, 244, 251}, /* Norm */
  	{0, 0, 0, 0,  81, 0, 131, 164, 188, 223, 243, 251, 257}, /* SGI */
  	{0, 0, 0, 0,  89, 0, 167, 235, 296, 402, 488, 526, 560}, /* AGG */
  	{0, 0, 0, 0,  97, 0, 182, 255, 320, 431, 520, 558, 593}, /* AGG+SGI*/
  };
  
  static s32 expected_tpt_mimo2_40MHz[4][IWL_RATE_COUNT] = {
  	{0, 0, 0, 0, 123, 0, 182, 214, 235, 264, 279, 285, 289}, /* Norm */
  	{0, 0, 0, 0, 131, 0, 191, 222, 242, 270, 284, 289, 293}, /* SGI */
  	{0, 0, 0, 0, 171, 0, 305, 410, 496, 634, 731, 771, 805}, /* AGG */
  	{0, 0, 0, 0, 186, 0, 329, 439, 527, 667, 764, 803, 838}, /* AGG+SGI */
  };
  
  static s32 expected_tpt_mimo3_20MHz[4][IWL_RATE_COUNT] = {
  	{0, 0, 0, 0,  99, 0, 153, 186, 208, 239, 256, 263, 268}, /* Norm */
  	{0, 0, 0, 0, 106, 0, 162, 194, 215, 246, 262, 268, 273}, /* SGI */
  	{0, 0, 0, 0, 134, 0, 249, 346, 431, 574, 685, 732, 775}, /* AGG */
  	{0, 0, 0, 0, 148, 0, 272, 376, 465, 614, 727, 775, 818}, /* AGG+SGI */
  };
  
  static s32 expected_tpt_mimo3_40MHz[4][IWL_RATE_COUNT] = {
  	{0, 0, 0, 0, 152, 0, 211, 239, 255, 279,  290,  294,  297}, /* Norm */
  	{0, 0, 0, 0, 160, 0, 219, 245, 261, 284,  294,  297,  300}, /* SGI */
  	{0, 0, 0, 0, 254, 0, 443, 584, 695, 868,  984, 1030, 1070}, /* AGG */
  	{0, 0, 0, 0, 277, 0, 478, 624, 737, 911, 1026, 1070, 1109}, /* AGG+SGI */
  };
  
  /* mbps, mcs */
  static const struct iwl_rate_mcs_info iwl_rate_mcs[IWL_RATE_COUNT] = {
  	{  "1", "BPSK DSSS"},
  	{  "2", "QPSK DSSS"},
  	{"5.5", "BPSK CCK"},
  	{ "11", "QPSK CCK"},
  	{  "6", "BPSK 1/2"},
  	{  "9", "BPSK 1/2"},
  	{ "12", "QPSK 1/2"},
  	{ "18", "QPSK 3/4"},
  	{ "24", "16QAM 1/2"},
  	{ "36", "16QAM 3/4"},
  	{ "48", "64QAM 2/3"},
  	{ "54", "64QAM 3/4"},
  	{ "60", "64QAM 5/6"},
  };
  
  #define MCS_INDEX_PER_STREAM	(8)
  
  static void rs_rate_scale_clear_window(struct iwl_rate_scale_data *window)
  {
  	window->data = 0;
  	window->success_counter = 0;
  	window->success_ratio = IWL_INVALID_VALUE;
  	window->counter = 0;
  	window->average_tpt = IWL_INVALID_VALUE;
  	window->stamp = 0;
  }
  
  static inline u8 rs_is_valid_ant(u8 valid_antenna, u8 ant_type)
  {
  	return (ant_type & valid_antenna) == ant_type;
  }
  
  /*
   *	removes the old data from the statistics. All data that is older than
   *	TID_MAX_TIME_DIFF, will be deleted.
   */
  static void rs_tl_rm_old_stats(struct iwl_traffic_load *tl, u32 curr_time)
  {
  	/* The oldest age we want to keep */
  	u32 oldest_time = curr_time - TID_MAX_TIME_DIFF;
  
  	while (tl->queue_count &&
  	       (tl->time_stamp < oldest_time)) {
  		tl->total -= tl->packet_count[tl->head];
  		tl->packet_count[tl->head] = 0;
  		tl->time_stamp += TID_QUEUE_CELL_SPACING;
  		tl->queue_count--;
  		tl->head++;
  		if (tl->head >= TID_QUEUE_MAX_SIZE)
  			tl->head = 0;
  	}
  }
  
  /*
   *	increment traffic load value for tid and also remove
   *	any old values if passed the certain time period
   */
  static u8 rs_tl_add_packet(struct iwl_lq_sta *lq_data,
  			   struct ieee80211_hdr *hdr)
  {
  	u32 curr_time = jiffies_to_msecs(jiffies);
  	u32 time_diff;
  	s32 index;
  	struct iwl_traffic_load *tl = NULL;
  	u8 tid;
  
  	if (ieee80211_is_data_qos(hdr->frame_control)) {
  		u8 *qc = ieee80211_get_qos_ctl(hdr);
  		tid = qc[0] & 0xf;
  	} else
  		return IWL_MAX_TID_COUNT;
  
  	if (unlikely(tid >= TID_MAX_LOAD_COUNT))
  		return IWL_MAX_TID_COUNT;
  
  	tl = &lq_data->load[tid];
  
  	curr_time -= curr_time % TID_ROUND_VALUE;
  
  	/* Happens only for the first packet. Initialize the data */
  	if (!(tl->queue_count)) {
  		tl->total = 1;
  		tl->time_stamp = curr_time;
  		tl->queue_count = 1;
  		tl->head = 0;
  		tl->packet_count[0] = 1;
  		return IWL_MAX_TID_COUNT;
  	}
  
  	time_diff = TIME_WRAP_AROUND(tl->time_stamp, curr_time);
  	index = time_diff / TID_QUEUE_CELL_SPACING;
  
  	/* The history is too long: remove data that is older than */
  	/* TID_MAX_TIME_DIFF */
  	if (index >= TID_QUEUE_MAX_SIZE)
  		rs_tl_rm_old_stats(tl, curr_time);
  
  	index = (tl->head + index) % TID_QUEUE_MAX_SIZE;
  	tl->packet_count[index] = tl->packet_count[index] + 1;
  	tl->total = tl->total + 1;
  
  	if ((index + 1) > tl->queue_count)
  		tl->queue_count = index + 1;
  
  	return tid;
  }
  
  #ifdef CONFIG_MAC80211_DEBUGFS
  /**
   * Program the device to use fixed rate for frame transmit
   * This is for debugging/testing only
   * once the device start use fixed rate, we need to reload the module
   * to being back the normal operation.
   */
  static void rs_program_fix_rate(struct iwl_priv *priv,
  				struct iwl_lq_sta *lq_sta)
  {
  	struct iwl_station_priv *sta_priv =
  		container_of(lq_sta, struct iwl_station_priv, lq_sta);
  	struct iwl_rxon_context *ctx = sta_priv->ctx;
  
  	lq_sta->active_legacy_rate = 0x0FFF;	/* 1 - 54 MBits, includes CCK */
  	lq_sta->active_siso_rate   = 0x1FD0;	/* 6 - 60 MBits, no 9, no CCK */
  	lq_sta->active_mimo2_rate  = 0x1FD0;	/* 6 - 60 MBits, no 9, no CCK */
  	lq_sta->active_mimo3_rate  = 0x1FD0;	/* 6 - 60 MBits, no 9, no CCK */
  
  #ifdef CONFIG_IWLWIFI_DEVICE_SVTOOL
  	/* testmode has higher priority to overwirte the fixed rate */
  	if (priv->tm_fixed_rate)
  		lq_sta->dbg_fixed_rate = priv->tm_fixed_rate;
  #endif
  
  	IWL_DEBUG_RATE(priv, "sta_id %d rate 0x%X\n",
  		lq_sta->lq.sta_id, lq_sta->dbg_fixed_rate);
  
  	if (lq_sta->dbg_fixed_rate) {
  		rs_fill_link_cmd(NULL, lq_sta, lq_sta->dbg_fixed_rate);
  		iwl_send_lq_cmd(lq_sta->drv, ctx, &lq_sta->lq, CMD_ASYNC,
  				false);
  	}
  }
  #endif
  
  /*
  	get the traffic load value for tid
  */
  static u32 rs_tl_get_load(struct iwl_lq_sta *lq_data, u8 tid)
  {
  	u32 curr_time = jiffies_to_msecs(jiffies);
  	u32 time_diff;
  	s32 index;
  	struct iwl_traffic_load *tl = NULL;
  
  	if (tid >= TID_MAX_LOAD_COUNT)
  		return 0;
  
  	tl = &(lq_data->load[tid]);
  
  	curr_time -= curr_time % TID_ROUND_VALUE;
  
  	if (!(tl->queue_count))
  		return 0;
  
  	time_diff = TIME_WRAP_AROUND(tl->time_stamp, curr_time);
  	index = time_diff / TID_QUEUE_CELL_SPACING;
  
  	/* The history is too long: remove data that is older than */
  	/* TID_MAX_TIME_DIFF */
  	if (index >= TID_QUEUE_MAX_SIZE)
  		rs_tl_rm_old_stats(tl, curr_time);
  
  	return tl->total;
  }
  
  static int rs_tl_turn_on_agg_for_tid(struct iwl_priv *priv,
  				      struct iwl_lq_sta *lq_data, u8 tid,
  				      struct ieee80211_sta *sta)
  {
  	int ret = -EAGAIN;
  	u32 load;
  
  	/*
  	 * Don't create TX aggregation sessions when in high
  	 * BT traffic, as they would just be disrupted by BT.
  	 */
  	if (priv->bt_traffic_load >= IWL_BT_COEX_TRAFFIC_LOAD_HIGH) {
  		IWL_ERR(priv, "BT traffic (%d), no aggregation allowed\n",
  			priv->bt_traffic_load);
  		return ret;
  	}
  
  	load = rs_tl_get_load(lq_data, tid);
  
  	if ((iwlagn_mod_params.auto_agg) || (load > IWL_AGG_LOAD_THRESHOLD)) {
  		IWL_DEBUG_HT(priv, "Starting Tx agg: STA: %pM tid: %d\n",
  				sta->addr, tid);
  		ret = ieee80211_start_tx_ba_session(sta, tid, 5000);
  		if (ret == -EAGAIN) {
  			/*
  			 * driver and mac80211 is out of sync
  			 * this might be cause by reloading firmware
  			 * stop the tx ba session here
  			 */
  			IWL_ERR(priv, "Fail start Tx agg on tid: %d\n",
  				tid);
  			ieee80211_stop_tx_ba_session(sta, tid);
  		}
  	} else {
  		IWL_DEBUG_HT(priv, "Aggregation not enabled for tid %d "
  			"because load = %u\n", tid, load);
  	}
  	return ret;
  }
  
  static void rs_tl_turn_on_agg(struct iwl_priv *priv, u8 tid,
  			      struct iwl_lq_sta *lq_data,
  			      struct ieee80211_sta *sta)
  {
  	if (tid < TID_MAX_LOAD_COUNT)
  		rs_tl_turn_on_agg_for_tid(priv, lq_data, tid, sta);
  	else
  		IWL_ERR(priv, "tid exceeds max load count: %d/%d\n",
  			tid, TID_MAX_LOAD_COUNT);
  }
  
  static inline int get_num_of_ant_from_rate(u32 rate_n_flags)
  {
  	return !!(rate_n_flags & RATE_MCS_ANT_A_MSK) +
  	       !!(rate_n_flags & RATE_MCS_ANT_B_MSK) +
  	       !!(rate_n_flags & RATE_MCS_ANT_C_MSK);
  }
  
  /*
   * Static function to get the expected throughput from an iwl_scale_tbl_info
   * that wraps a NULL pointer check
   */
  static s32 get_expected_tpt(struct iwl_scale_tbl_info *tbl, int rs_index)
  {
  	if (tbl->expected_tpt)
  		return tbl->expected_tpt[rs_index];
  	return 0;
  }
  
  /**
   * rs_collect_tx_data - Update the success/failure sliding window
   *
   * We keep a sliding window of the last 62 packets transmitted
   * at this rate.  window->data contains the bitmask of successful
   * packets.
   */
  static int rs_collect_tx_data(struct iwl_scale_tbl_info *tbl,
  			      int scale_index, int attempts, int successes)
  {
  	struct iwl_rate_scale_data *window = NULL;
  	static const u64 mask = (((u64)1) << (IWL_RATE_MAX_WINDOW - 1));
  	s32 fail_count, tpt;
  
  	if (scale_index < 0 || scale_index >= IWL_RATE_COUNT)
  		return -EINVAL;
  
  	/* Select window for current tx bit rate */
  	window = &(tbl->win[scale_index]);
  
  	/* Get expected throughput */
  	tpt = get_expected_tpt(tbl, scale_index);
  
  	/*
  	 * 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 (attempts > 0) {
  		if (window->counter >= IWL_RATE_MAX_WINDOW) {
  
  			/* remove earliest */
  			window->counter = IWL_RATE_MAX_WINDOW - 1;
  
  			if (window->data & mask) {
  				window->data &= ~mask;
  				window->success_counter--;
  			}
  		}
  
  		/* Increment frames-attempted counter */
  		window->counter++;
  
  		/* Shift bitmap by one frame to throw away oldest history */
  		window->data <<= 1;
  
  		/* Mark the most recent #successes attempts as successful */
  		if (successes > 0) {
  			window->success_counter++;
  			window->data |= 0x1;
  			successes--;
  		}
  
  		attempts--;
  	}
  
  	/* 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 * tpt + 64) / 128;
  	else
  		window->average_tpt = IWL_INVALID_VALUE;
  
  	/* Tag this window as having been updated */
  	window->stamp = jiffies;
  
  	return 0;
  }
  
  /*
   * Fill uCode API rate_n_flags field, based on "search" or "active" table.
   */
  /* FIXME:RS:remove this function and put the flags statically in the table */
  static u32 rate_n_flags_from_tbl(struct iwl_priv *priv,
  				 struct iwl_scale_tbl_info *tbl,
  				 int index, u8 use_green)
  {
  	u32 rate_n_flags = 0;
  
  	if (is_legacy(tbl->lq_type)) {
  		rate_n_flags = iwl_rates[index].plcp;
  		if (index >= IWL_FIRST_CCK_RATE && index <= IWL_LAST_CCK_RATE)
  			rate_n_flags |= RATE_MCS_CCK_MSK;
  
  	} else if (is_Ht(tbl->lq_type)) {
  		if (index > IWL_LAST_OFDM_RATE) {
  			IWL_ERR(priv, "Invalid HT rate index %d\n", index);
  			index = IWL_LAST_OFDM_RATE;
  		}
  		rate_n_flags = RATE_MCS_HT_MSK;
  
  		if (is_siso(tbl->lq_type))
  			rate_n_flags |=	iwl_rates[index].plcp_siso;
  		else if (is_mimo2(tbl->lq_type))
  			rate_n_flags |=	iwl_rates[index].plcp_mimo2;
  		else
  			rate_n_flags |=	iwl_rates[index].plcp_mimo3;
  	} else {
  		IWL_ERR(priv, "Invalid tbl->lq_type %d\n", tbl->lq_type);
  	}
  
  	rate_n_flags |= ((tbl->ant_type << RATE_MCS_ANT_POS) &
  						     RATE_MCS_ANT_ABC_MSK);
  
  	if (is_Ht(tbl->lq_type)) {
  		if (tbl->is_ht40) {
  			if (tbl->is_dup)
  				rate_n_flags |= RATE_MCS_DUP_MSK;
  			else
  				rate_n_flags |= RATE_MCS_HT40_MSK;
  		}
  		if (tbl->is_SGI)
  			rate_n_flags |= RATE_MCS_SGI_MSK;
  
  		if (use_green) {
  			rate_n_flags |= RATE_MCS_GF_MSK;
  			if (is_siso(tbl->lq_type) && tbl->is_SGI) {
  				rate_n_flags &= ~RATE_MCS_SGI_MSK;
  				IWL_ERR(priv, "GF was set with SGI:SISO\n");
  			}
  		}
  	}
  	return rate_n_flags;
  }
  
  /*
   * Interpret uCode API's rate_n_flags format,
   * fill "search" or "active" tx mode table.
   */
  static int rs_get_tbl_info_from_mcs(const u32 rate_n_flags,
  				    enum ieee80211_band band,
  				    struct iwl_scale_tbl_info *tbl,
  				    int *rate_idx)
  {
  	u32 ant_msk = (rate_n_flags & RATE_MCS_ANT_ABC_MSK);
  	u8 num_of_ant = get_num_of_ant_from_rate(rate_n_flags);
  	u8 mcs;
  
  	memset(tbl, 0, sizeof(struct iwl_scale_tbl_info));
  	*rate_idx = iwl_hwrate_to_plcp_idx(rate_n_flags);
  
  	if (*rate_idx  == IWL_RATE_INVALID) {
  		*rate_idx = -1;
  		return -EINVAL;
  	}
  	tbl->is_SGI = 0;	/* default legacy setup */
  	tbl->is_ht40 = 0;
  	tbl->is_dup = 0;
  	tbl->ant_type = (ant_msk >> RATE_MCS_ANT_POS);
  	tbl->lq_type = LQ_NONE;
  	tbl->max_search = IWL_MAX_SEARCH;
  
  	/* legacy rate format */
  	if (!(rate_n_flags & RATE_MCS_HT_MSK)) {
  		if (num_of_ant == 1) {
  			if (band == IEEE80211_BAND_5GHZ)
  				tbl->lq_type = LQ_A;
  			else
  				tbl->lq_type = LQ_G;
  		}
  	/* HT rate format */
  	} else {
  		if (rate_n_flags & RATE_MCS_SGI_MSK)
  			tbl->is_SGI = 1;
  
  		if ((rate_n_flags & RATE_MCS_HT40_MSK) ||
  		    (rate_n_flags & RATE_MCS_DUP_MSK))
  			tbl->is_ht40 = 1;
  
  		if (rate_n_flags & RATE_MCS_DUP_MSK)
  			tbl->is_dup = 1;
  
  		mcs = rs_extract_rate(rate_n_flags);
  
  		/* SISO */
  		if (mcs <= IWL_RATE_SISO_60M_PLCP) {
  			if (num_of_ant == 1)
  				tbl->lq_type = LQ_SISO; /*else NONE*/
  		/* MIMO2 */
  		} else if (mcs <= IWL_RATE_MIMO2_60M_PLCP) {
  			if (num_of_ant == 2)
  				tbl->lq_type = LQ_MIMO2;
  		/* MIMO3 */
  		} else {
  			if (num_of_ant == 3) {
  				tbl->max_search = IWL_MAX_11N_MIMO3_SEARCH;
  				tbl->lq_type = LQ_MIMO3;
  			}
  		}
  	}
  	return 0;
  }
  
  /* switch to another antenna/antennas and return 1 */
  /* if no other valid antenna found, return 0 */
  static int rs_toggle_antenna(u32 valid_ant, u32 *rate_n_flags,
  			     struct iwl_scale_tbl_info *tbl)
  {
  	u8 new_ant_type;
  
  	if (!tbl->ant_type || tbl->ant_type > ANT_ABC)
  		return 0;
  
  	if (!rs_is_valid_ant(valid_ant, tbl->ant_type))
  		return 0;
  
  	new_ant_type = ant_toggle_lookup[tbl->ant_type];
  
  	while ((new_ant_type != tbl->ant_type) &&
  	       !rs_is_valid_ant(valid_ant, new_ant_type))
  		new_ant_type = ant_toggle_lookup[new_ant_type];
  
  	if (new_ant_type == tbl->ant_type)
  		return 0;
  
  	tbl->ant_type = new_ant_type;
  	*rate_n_flags &= ~RATE_MCS_ANT_ABC_MSK;
  	*rate_n_flags |= new_ant_type << RATE_MCS_ANT_POS;
  	return 1;
  }
  
  /**
   * Green-field mode is valid if the station supports it and
   * there are no non-GF stations present in the BSS.
   */
  static bool rs_use_green(struct ieee80211_sta *sta)
  {
  	struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
  	struct iwl_rxon_context *ctx = sta_priv->ctx;
  
  	return (sta->ht_cap.cap & IEEE80211_HT_CAP_GRN_FLD) &&
  		!(ctx->ht.non_gf_sta_present);
  }
  
  /**
   * rs_get_supported_rates - get the available rates
   *
   * if management frame or broadcast frame only return
   * basic available rates.
   *
   */
  static u16 rs_get_supported_rates(struct iwl_lq_sta *lq_sta,
  				  struct ieee80211_hdr *hdr,
  				  enum iwl_table_type rate_type)
  {
  	if (is_legacy(rate_type)) {
  		return lq_sta->active_legacy_rate;
  	} else {
  		if (is_siso(rate_type))
  			return lq_sta->active_siso_rate;
  		else if (is_mimo2(rate_type))
  			return lq_sta->active_mimo2_rate;
  		else
  			return lq_sta->active_mimo3_rate;
  	}
  }
  
  static u16 rs_get_adjacent_rate(struct iwl_priv *priv, u8 index, u16 rate_mask,
  				int rate_type)
  {
  	u8 high = IWL_RATE_INVALID;
  	u8 low = IWL_RATE_INVALID;
  
  	/* 802.11A or ht walks to the next literal adjacent rate in
  	 * the rate table */
  	if (is_a_band(rate_type) || !is_legacy(rate_type)) {
  		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; i++, mask <<= 1) {
  			if (rate_mask & mask) {
  				high = i;
  				break;
  			}
  		}
  
  		return (high << 8) | low;
  	}
  
  	low = index;
  	while (low != IWL_RATE_INVALID) {
  		low = iwl_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) {
  		high = iwl_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;
  }
  
  static u32 rs_get_lower_rate(struct iwl_lq_sta *lq_sta,
  			     struct iwl_scale_tbl_info *tbl,
  			     u8 scale_index, u8 ht_possible)
  {
  	s32 low;
  	u16 rate_mask;
  	u16 high_low;
  	u8 switch_to_legacy = 0;
  	u8 is_green = lq_sta->is_green;
  	struct iwl_priv *priv = lq_sta->drv;
  
  	/* check if we need to switch from HT to legacy rates.
  	 * assumption is that mandatory rates (1Mbps or 6Mbps)
  	 * are always supported (spec demand) */
  	if (!is_legacy(tbl->lq_type) && (!ht_possible || !scale_index)) {
  		switch_to_legacy = 1;
  		scale_index = rs_ht_to_legacy[scale_index];
  		if (lq_sta->band == IEEE80211_BAND_5GHZ)
  			tbl->lq_type = LQ_A;
  		else
  			tbl->lq_type = LQ_G;
  
  		if (num_of_ant(tbl->ant_type) > 1)
  			tbl->ant_type =
  			    first_antenna(hw_params(priv).valid_tx_ant);
  
  		tbl->is_ht40 = 0;
  		tbl->is_SGI = 0;
  		tbl->max_search = IWL_MAX_SEARCH;
  	}
  
  	rate_mask = rs_get_supported_rates(lq_sta, NULL, tbl->lq_type);
  
  	/* Mask with station rate restriction */
  	if (is_legacy(tbl->lq_type)) {
  		/* supp_rates has no CCK bits in A mode */
  		if (lq_sta->band == IEEE80211_BAND_5GHZ)
  			rate_mask  = (u16)(rate_mask &
  			   (lq_sta->supp_rates << IWL_FIRST_OFDM_RATE));
  		else
  			rate_mask = (u16)(rate_mask & lq_sta->supp_rates);
  	}
  
  	/* If we switched from HT to legacy, check current rate */
  	if (switch_to_legacy && (rate_mask & (1 << scale_index))) {
  		low = scale_index;
  		goto out;
  	}
  
  	high_low = rs_get_adjacent_rate(lq_sta->drv, scale_index, rate_mask,
  					tbl->lq_type);
  	low = high_low & 0xff;
  
  	if (low == IWL_RATE_INVALID)
  		low = scale_index;
  
  out:
  	return rate_n_flags_from_tbl(lq_sta->drv, tbl, low, is_green);
  }
  
  /*
   * Simple function to compare two rate scale table types
   */
  static bool table_type_matches(struct iwl_scale_tbl_info *a,
  			       struct iwl_scale_tbl_info *b)
  {
  	return (a->lq_type == b->lq_type) && (a->ant_type == b->ant_type) &&
  		(a->is_SGI == b->is_SGI);
  }
  
  static void rs_bt_update_lq(struct iwl_priv *priv, struct iwl_rxon_context *ctx,
  			    struct iwl_lq_sta *lq_sta)
  {
  	struct iwl_scale_tbl_info *tbl;
  	bool full_concurrent = priv->bt_full_concurrent;
  	unsigned long flags;
  
  	if (priv->bt_ant_couple_ok) {
  		/*
  		 * Is there a need to switch between
  		 * full concurrency and 3-wire?
  		 */
  		spin_lock_irqsave(&priv->shrd->lock, flags);
  		if (priv->bt_ci_compliance && priv->bt_ant_couple_ok)
  			full_concurrent = true;
  		else
  			full_concurrent = false;
  		spin_unlock_irqrestore(&priv->shrd->lock, flags);
  	}
  	if ((priv->bt_traffic_load != priv->last_bt_traffic_load) ||
  	    (priv->bt_full_concurrent != full_concurrent)) {
  		priv->bt_full_concurrent = full_concurrent;
  
  		/* Update uCode's rate table. */
  		tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
  		rs_fill_link_cmd(priv, lq_sta, tbl->current_rate);
  		iwl_send_lq_cmd(priv, ctx, &lq_sta->lq, CMD_ASYNC, false);
  
  		queue_work(priv->shrd->workqueue, &priv->bt_full_concurrency);
  	}
  }
  
  /*
   * mac80211 sends us Tx status
   */
  static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband,
  			 struct ieee80211_sta *sta, void *priv_sta,
  			 struct sk_buff *skb)
  {
  	int legacy_success;
  	int retries;
  	int rs_index, mac_index, i;
  	struct iwl_lq_sta *lq_sta = priv_sta;
  	struct iwl_link_quality_cmd *table;
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  	struct iwl_priv *priv = (struct iwl_priv *)priv_r;
  	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  	enum mac80211_rate_control_flags mac_flags;
  	u32 tx_rate;
  	struct iwl_scale_tbl_info tbl_type;
  	struct iwl_scale_tbl_info *curr_tbl, *other_tbl, *tmp_tbl;
  	struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
  	struct iwl_rxon_context *ctx = sta_priv->ctx;
  
  	IWL_DEBUG_RATE_LIMIT(priv, "get frame ack response, update rate scale window\n");
  
  	/* Treat uninitialized rate scaling data same as non-existing. */
  	if (!lq_sta) {
  		IWL_DEBUG_RATE(priv, "Station rate scaling not created yet.\n");
  		return;
  	} else if (!lq_sta->drv) {
  		IWL_DEBUG_RATE(priv, "Rate scaling not initialized yet.\n");
  		return;
  	}
  
  	if (!ieee80211_is_data(hdr->frame_control) ||
  	    info->flags & IEEE80211_TX_CTL_NO_ACK)
  		return;
  
  	/* This packet was aggregated but doesn't carry status info */
  	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
  	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
  		return;
  
  	/*
  	 * Ignore this Tx frame response if its initial rate doesn't match
  	 * that of latest Link Quality command.  There may be stragglers
  	 * from a previous Link Quality command, but we're no longer interested
  	 * in those; they're either from the "active" mode while we're trying
  	 * to check "search" mode, or a prior "search" mode after we've moved
  	 * to a new "search" mode (which might become the new "active" mode).
  	 */
  	table = &lq_sta->lq;
  	tx_rate = le32_to_cpu(table->rs_table[0].rate_n_flags);
  	rs_get_tbl_info_from_mcs(tx_rate, priv->band, &tbl_type, &rs_index);
  	if (priv->band == IEEE80211_BAND_5GHZ)
  		rs_index -= IWL_FIRST_OFDM_RATE;
  	mac_flags = info->status.rates[0].flags;
  	mac_index = info->status.rates[0].idx;
  	/* For HT packets, map MCS to PLCP */
  	if (mac_flags & IEEE80211_TX_RC_MCS) {
  		mac_index &= RATE_MCS_CODE_MSK;	/* Remove # of streams */
  		if (mac_index >= (IWL_RATE_9M_INDEX - IWL_FIRST_OFDM_RATE))
  			mac_index++;
  		/*
  		 * mac80211 HT index is always zero-indexed; we need to move
  		 * HT OFDM rates after CCK rates in 2.4 GHz band
  		 */
  		if (priv->band == IEEE80211_BAND_2GHZ)
  			mac_index += IWL_FIRST_OFDM_RATE;
  	}
  	/* Here we actually compare this rate to the latest LQ command */
  	if ((mac_index < 0) ||
  	    (tbl_type.is_SGI != !!(mac_flags & IEEE80211_TX_RC_SHORT_GI)) ||
  	    (tbl_type.is_ht40 != !!(mac_flags & IEEE80211_TX_RC_40_MHZ_WIDTH)) ||
  	    (tbl_type.is_dup != !!(mac_flags & IEEE80211_TX_RC_DUP_DATA)) ||
  	    (tbl_type.ant_type != info->antenna_sel_tx) ||
  	    (!!(tx_rate & RATE_MCS_HT_MSK) != !!(mac_flags & IEEE80211_TX_RC_MCS)) ||
  	    (!!(tx_rate & RATE_MCS_GF_MSK) != !!(mac_flags & IEEE80211_TX_RC_GREEN_FIELD)) ||
  	    (rs_index != mac_index)) {
  		IWL_DEBUG_RATE(priv, "initial rate %d does not match %d (0x%x)\n", mac_index, rs_index, tx_rate);
  		/*
  		 * Since rates mis-match, the last LQ command may have failed.
  		 * After IWL_MISSED_RATE_MAX mis-matches, resync the uCode with
  		 * ... driver.
  		 */
  		lq_sta->missed_rate_counter++;
  		if (lq_sta->missed_rate_counter > IWL_MISSED_RATE_MAX) {
  			lq_sta->missed_rate_counter = 0;
  			iwl_send_lq_cmd(priv, ctx, &lq_sta->lq, CMD_ASYNC, false);
  		}
  		/* Regardless, ignore this status info for outdated rate */
  		return;
  	} else
  		/* Rate did match, so reset the missed_rate_counter */
  		lq_sta->missed_rate_counter = 0;
  
  	/* Figure out if rate scale algorithm is in active or search table */
  	if (table_type_matches(&tbl_type,
  				&(lq_sta->lq_info[lq_sta->active_tbl]))) {
  		curr_tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
  		other_tbl = &(lq_sta->lq_info[1 - lq_sta->active_tbl]);
  	} else if (table_type_matches(&tbl_type,
  				&lq_sta->lq_info[1 - lq_sta->active_tbl])) {
  		curr_tbl = &(lq_sta->lq_info[1 - lq_sta->active_tbl]);
  		other_tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
  	} else {
  		IWL_DEBUG_RATE(priv, "Neither active nor search matches tx rate\n");
  		tmp_tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
  		IWL_DEBUG_RATE(priv, "active- lq:%x, ant:%x, SGI:%d\n",
  			tmp_tbl->lq_type, tmp_tbl->ant_type, tmp_tbl->is_SGI);
  		tmp_tbl = &(lq_sta->lq_info[1 - lq_sta->active_tbl]);
  		IWL_DEBUG_RATE(priv, "search- lq:%x, ant:%x, SGI:%d\n",
  			tmp_tbl->lq_type, tmp_tbl->ant_type, tmp_tbl->is_SGI);
  		IWL_DEBUG_RATE(priv, "actual- lq:%x, ant:%x, SGI:%d\n",
  			tbl_type.lq_type, tbl_type.ant_type, tbl_type.is_SGI);
  		/*
  		 * no matching table found, let's by-pass the data collection
  		 * and continue to perform rate scale to find the rate table
  		 */
  		rs_stay_in_table(lq_sta, true);
  		goto done;
  	}
  
  	/*
  	 * Updating the frame history depends on whether packets were
  	 * aggregated.
  	 *
  	 * For aggregation, all packets were transmitted at the same rate, the
  	 * first index into rate scale table.
  	 */
  	if (info->flags & IEEE80211_TX_STAT_AMPDU) {
  		tx_rate = le32_to_cpu(table->rs_table[0].rate_n_flags);
  		rs_get_tbl_info_from_mcs(tx_rate, priv->band, &tbl_type,
  				&rs_index);
  		rs_collect_tx_data(curr_tbl, rs_index,
  				   info->status.ampdu_len,
  				   info->status.ampdu_ack_len);
  
  		/* Update success/fail counts if not searching for new mode */
  		if (lq_sta->stay_in_tbl) {
  			lq_sta->total_success += info->status.ampdu_ack_len;
  			lq_sta->total_failed += (info->status.ampdu_len -
  					info->status.ampdu_ack_len);
  		}
  	} else {
  	/*
  	 * For legacy, update frame history with for each Tx retry.
  	 */
  		retries = info->status.rates[0].count - 1;
  		/* HW doesn't send more than 15 retries */
  		retries = min(retries, 15);
  
  		/* The last transmission may have been successful */
  		legacy_success = !!(info->flags & IEEE80211_TX_STAT_ACK);
  		/* Collect data for each rate used during failed TX attempts */
  		for (i = 0; i <= retries; ++i) {
  			tx_rate = le32_to_cpu(table->rs_table[i].rate_n_flags);
  			rs_get_tbl_info_from_mcs(tx_rate, priv->band,
  					&tbl_type, &rs_index);
  			/*
  			 * Only collect stats if retried rate is in the same RS
  			 * table as active/search.
  			 */
  			if (table_type_matches(&tbl_type, curr_tbl))
  				tmp_tbl = curr_tbl;
  			else if (table_type_matches(&tbl_type, other_tbl))
  				tmp_tbl = other_tbl;
  			else
  				continue;
  			rs_collect_tx_data(tmp_tbl, rs_index, 1,
  					   i < retries ? 0 : legacy_success);
  		}
  
  		/* Update success/fail counts if not searching for new mode */
  		if (lq_sta->stay_in_tbl) {
  			lq_sta->total_success += legacy_success;
  			lq_sta->total_failed += retries + (1 - legacy_success);
  		}
  	}
  	/* The last TX rate is cached in lq_sta; it's set in if/else above */
  	lq_sta->last_rate_n_flags = tx_rate;
  done:
  	/* See if there's a better rate or modulation mode to try. */
  	if (sta && sta->supp_rates[sband->band])
  		rs_rate_scale_perform(priv, skb, sta, lq_sta);
  
  #if defined(CONFIG_MAC80211_DEBUGFS) && defined(CONFIG_IWLWIFI_DEVICE_SVTOOL)
  	if ((priv->tm_fixed_rate) &&
  	    (priv->tm_fixed_rate != lq_sta->dbg_fixed_rate))
  		rs_program_fix_rate(priv, lq_sta);
  #endif
  	if (priv->cfg->bt_params && priv->cfg->bt_params->advanced_bt_coexist)
  		rs_bt_update_lq(priv, ctx, lq_sta);
  }
  
  /*
   * Begin a period of staying with a selected modulation mode.
   * Set "stay_in_tbl" flag to prevent any mode switches.
   * Set frame tx success limits according to legacy vs. high-throughput,
   * and reset overall (spanning all rates) tx success history statistics.
   * These control how long we stay using same modulation mode before
   * searching for a new mode.
   */
  static void rs_set_stay_in_table(struct iwl_priv *priv, u8 is_legacy,
  				 struct iwl_lq_sta *lq_sta)
  {
  	IWL_DEBUG_RATE(priv, "we are staying in the same table\n");
  	lq_sta->stay_in_tbl = 1;	/* only place this gets set */
  	if (is_legacy) {
  		lq_sta->table_count_limit = IWL_LEGACY_TABLE_COUNT;
  		lq_sta->max_failure_limit = IWL_LEGACY_FAILURE_LIMIT;
  		lq_sta->max_success_limit = IWL_LEGACY_SUCCESS_LIMIT;
  	} else {
  		lq_sta->table_count_limit = IWL_NONE_LEGACY_TABLE_COUNT;
  		lq_sta->max_failure_limit = IWL_NONE_LEGACY_FAILURE_LIMIT;
  		lq_sta->max_success_limit = IWL_NONE_LEGACY_SUCCESS_LIMIT;
  	}
  	lq_sta->table_count = 0;
  	lq_sta->total_failed = 0;
  	lq_sta->total_success = 0;
  	lq_sta->flush_timer = jiffies;
  	lq_sta->action_counter = 0;
  }
  
  /*
   * Find correct throughput table for given mode of modulation
   */
  static void rs_set_expected_tpt_table(struct iwl_lq_sta *lq_sta,
  				      struct iwl_scale_tbl_info *tbl)
  {
  	/* Used to choose among HT tables */
  	s32 (*ht_tbl_pointer)[IWL_RATE_COUNT];
  
  	/* Check for invalid LQ type */
  	if (WARN_ON_ONCE(!is_legacy(tbl->lq_type) && !is_Ht(tbl->lq_type))) {
  		tbl->expected_tpt = expected_tpt_legacy;
  		return;
  	}
  
  	/* Legacy rates have only one table */
  	if (is_legacy(tbl->lq_type)) {
  		tbl->expected_tpt = expected_tpt_legacy;
  		return;
  	}
  
  	/* Choose among many HT tables depending on number of streams
  	 * (SISO/MIMO2/MIMO3), channel width (20/40), SGI, and aggregation
  	 * status */
  	if (is_siso(tbl->lq_type) && (!tbl->is_ht40 || lq_sta->is_dup))
  		ht_tbl_pointer = expected_tpt_siso20MHz;
  	else if (is_siso(tbl->lq_type))
  		ht_tbl_pointer = expected_tpt_siso40MHz;
  	else if (is_mimo2(tbl->lq_type) && (!tbl->is_ht40 || lq_sta->is_dup))
  		ht_tbl_pointer = expected_tpt_mimo2_20MHz;
  	else if (is_mimo2(tbl->lq_type))
  		ht_tbl_pointer = expected_tpt_mimo2_40MHz;
  	else if (is_mimo3(tbl->lq_type) && (!tbl->is_ht40 || lq_sta->is_dup))
  		ht_tbl_pointer = expected_tpt_mimo3_20MHz;
  	else /* if (is_mimo3(tbl->lq_type)) <-- must be true */
  		ht_tbl_pointer = expected_tpt_mimo3_40MHz;
  
  	if (!tbl->is_SGI && !lq_sta->is_agg)		/* Normal */
  		tbl->expected_tpt = ht_tbl_pointer[0];
  	else if (tbl->is_SGI && !lq_sta->is_agg)	/* SGI */
  		tbl->expected_tpt = ht_tbl_pointer[1];
  	else if (!tbl->is_SGI && lq_sta->is_agg)	/* AGG */
  		tbl->expected_tpt = ht_tbl_pointer[2];
  	else						/* AGG+SGI */
  		tbl->expected_tpt = ht_tbl_pointer[3];
  }
  
  /*
   * Find starting rate for new "search" high-throughput mode of modulation.
   * Goal is to find lowest expected rate (under perfect conditions) that is
   * above the current measured throughput of "active" mode, to give new mode
   * a fair chance to prove itself without too many challenges.
   *
   * This gets called when transitioning to more aggressive modulation
   * (i.e. legacy to SISO or MIMO, or SISO to MIMO), as well as less aggressive
   * (i.e. MIMO to SISO).  When moving to MIMO, bit rate will typically need
   * to decrease to match "active" throughput.  When moving from MIMO to SISO,
   * bit rate will typically need to increase, but not if performance was bad.
   */
  static s32 rs_get_best_rate(struct iwl_priv *priv,
  			    struct iwl_lq_sta *lq_sta,
  			    struct iwl_scale_tbl_info *tbl,	/* "search" */
  			    u16 rate_mask, s8 index)
  {
  	/* "active" values */
  	struct iwl_scale_tbl_info *active_tbl =
  	    &(lq_sta->lq_info[lq_sta->active_tbl]);
  	s32 active_sr = active_tbl->win[index].success_ratio;
  	s32 active_tpt = active_tbl->expected_tpt[index];
  
  	/* expected "search" throughput */
  	s32 *tpt_tbl = tbl->expected_tpt;
  
  	s32 new_rate, high, low, start_hi;
  	u16 high_low;
  	s8 rate = index;
  
  	new_rate = high = low = start_hi = IWL_RATE_INVALID;
  
  	for (; ;) {
  		high_low = rs_get_adjacent_rate(priv, rate, rate_mask,
  						tbl->lq_type);
  
  		low = high_low & 0xff;
  		high = (high_low >> 8) & 0xff;
  
  		/*
  		 * Lower the "search" bit rate, to give new "search" mode
  		 * approximately the same throughput as "active" if:
  		 *
  		 * 1) "Active" mode has been working modestly well (but not
  		 *    great), and expected "search" throughput (under perfect
  		 *    conditions) at candidate rate is above the actual
  		 *    measured "active" throughput (but less than expected
  		 *    "active" throughput under perfect conditions).
  		 * OR
  		 * 2) "Active" mode has been working perfectly or very well
  		 *    and expected "search" throughput (under perfect
  		 *    conditions) at candidate rate is above expected
  		 *    "active" throughput (under perfect conditions).
  		 */
  		if ((((100 * tpt_tbl[rate]) > lq_sta->last_tpt) &&
  		     ((active_sr > IWL_RATE_DECREASE_TH) &&
  		      (active_sr <= IWL_RATE_HIGH_TH) &&
  		      (tpt_tbl[rate] <= active_tpt))) ||
  		    ((active_sr >= IWL_RATE_SCALE_SWITCH) &&
  		     (tpt_tbl[rate] > active_tpt))) {
  
  			/* (2nd or later pass)
  			 * If we've already tried to raise the rate, and are
  			 * now trying to lower it, use the higher rate. */
  			if (start_hi != IWL_RATE_INVALID) {
  				new_rate = start_hi;
  				break;
  			}
  
  			new_rate = rate;
  
  			/* Loop again with lower rate */
  			if (low != IWL_RATE_INVALID)
  				rate = low;
  
  			/* Lower rate not available, use the original */
  			else
  				break;
  
  		/* Else try to raise the "search" rate to match "active" */
  		} else {
  			/* (2nd or later pass)
  			 * If we've already tried to lower the rate, and are
  			 * now trying to raise it, use the lower rate. */
  			if (new_rate != IWL_RATE_INVALID)
  				break;
  
  			/* Loop again with higher rate */
  			else if (high != IWL_RATE_INVALID) {
  				start_hi = high;
  				rate = high;
  
  			/* Higher rate not available, use the original */
  			} else {
  				new_rate = rate;
  				break;
  			}
  		}
  	}
  
  	return new_rate;
  }
  
  /*
   * Set up search table for MIMO2
   */
  static int rs_switch_to_mimo2(struct iwl_priv *priv,
  			     struct iwl_lq_sta *lq_sta,
  			     struct ieee80211_conf *conf,
  			     struct ieee80211_sta *sta,
  			     struct iwl_scale_tbl_info *tbl, int index)
  {
  	u16 rate_mask;
  	s32 rate;
  	s8 is_green = lq_sta->is_green;
  	struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
  	struct iwl_rxon_context *ctx = sta_priv->ctx;
  
  	if (!conf_is_ht(conf) || !sta->ht_cap.ht_supported)
  		return -1;
  
  	if (((sta->ht_cap.cap & IEEE80211_HT_CAP_SM_PS) >> 2)
  						== WLAN_HT_CAP_SM_PS_STATIC)
  		return -1;
  
  	/* Need both Tx chains/antennas to support MIMO */
  	if (hw_params(priv).tx_chains_num < 2)
  		return -1;
  
  	IWL_DEBUG_RATE(priv, "LQ: try to switch to MIMO2\n");
  
  	tbl->lq_type = LQ_MIMO2;
  	tbl->is_dup = lq_sta->is_dup;
  	tbl->action = 0;
  	tbl->max_search = IWL_MAX_SEARCH;
  	rate_mask = lq_sta->active_mimo2_rate;
  
  	if (iwl_is_ht40_tx_allowed(priv, ctx, &sta->ht_cap))
  		tbl->is_ht40 = 1;
  	else
  		tbl->is_ht40 = 0;
  
  	rs_set_expected_tpt_table(lq_sta, tbl);
  
  	rate = rs_get_best_rate(priv, lq_sta, tbl, rate_mask, index);
  
  	IWL_DEBUG_RATE(priv, "LQ: MIMO2 best rate %d mask %X\n", rate, rate_mask);
  	if ((rate == IWL_RATE_INVALID) || !((1 << rate) & rate_mask)) {
  		IWL_DEBUG_RATE(priv, "Can't switch with index %d rate mask %x\n",
  						rate, rate_mask);
  		return -1;
  	}
  	tbl->current_rate = rate_n_flags_from_tbl(priv, tbl, rate, is_green);
  
  	IWL_DEBUG_RATE(priv, "LQ: Switch to new mcs %X index is green %X\n",
  		     tbl->current_rate, is_green);
  	return 0;
  }
  
  /*
   * Set up search table for MIMO3
   */
  static int rs_switch_to_mimo3(struct iwl_priv *priv,
  			     struct iwl_lq_sta *lq_sta,
  			     struct ieee80211_conf *conf,
  			     struct ieee80211_sta *sta,
  			     struct iwl_scale_tbl_info *tbl, int index)
  {
  	u16 rate_mask;
  	s32 rate;
  	s8 is_green = lq_sta->is_green;
  	struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
  	struct iwl_rxon_context *ctx = sta_priv->ctx;
  
  	if (!conf_is_ht(conf) || !sta->ht_cap.ht_supported)
  		return -1;
  
  	if (((sta->ht_cap.cap & IEEE80211_HT_CAP_SM_PS) >> 2)
  						== WLAN_HT_CAP_SM_PS_STATIC)
  		return -1;
  
  	/* Need both Tx chains/antennas to support MIMO */
  	if (hw_params(priv).tx_chains_num < 3)
  		return -1;
  
  	IWL_DEBUG_RATE(priv, "LQ: try to switch to MIMO3\n");
  
  	tbl->lq_type = LQ_MIMO3;
  	tbl->is_dup = lq_sta->is_dup;
  	tbl->action = 0;
  	tbl->max_search = IWL_MAX_11N_MIMO3_SEARCH;
  	rate_mask = lq_sta->active_mimo3_rate;
  
  	if (iwl_is_ht40_tx_allowed(priv, ctx, &sta->ht_cap))
  		tbl->is_ht40 = 1;
  	else
  		tbl->is_ht40 = 0;
  
  	rs_set_expected_tpt_table(lq_sta, tbl);
  
  	rate = rs_get_best_rate(priv, lq_sta, tbl, rate_mask, index);
  
  	IWL_DEBUG_RATE(priv, "LQ: MIMO3 best rate %d mask %X\n",
  		rate, rate_mask);
  	if ((rate == IWL_RATE_INVALID) || !((1 << rate) & rate_mask)) {
  		IWL_DEBUG_RATE(priv, "Can't switch with index %d rate mask %x\n",
  						rate, rate_mask);
  		return -1;
  	}
  	tbl->current_rate = rate_n_flags_from_tbl(priv, tbl, rate, is_green);
  
  	IWL_DEBUG_RATE(priv, "LQ: Switch to new mcs %X index is green %X\n",
  		     tbl->current_rate, is_green);
  	return 0;
  }
  
  /*
   * Set up search table for SISO
   */
  static int rs_switch_to_siso(struct iwl_priv *priv,
  			     struct iwl_lq_sta *lq_sta,
  			     struct ieee80211_conf *conf,
  			     struct ieee80211_sta *sta,
  			     struct iwl_scale_tbl_info *tbl, int index)
  {
  	u16 rate_mask;
  	u8 is_green = lq_sta->is_green;
  	s32 rate;
  	struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
  	struct iwl_rxon_context *ctx = sta_priv->ctx;
  
  	if (!conf_is_ht(conf) || !sta->ht_cap.ht_supported)
  		return -1;
  
  	IWL_DEBUG_RATE(priv, "LQ: try to switch to SISO\n");
  
  	tbl->is_dup = lq_sta->is_dup;
  	tbl->lq_type = LQ_SISO;
  	tbl->action = 0;
  	tbl->max_search = IWL_MAX_SEARCH;
  	rate_mask = lq_sta->active_siso_rate;
  
  	if (iwl_is_ht40_tx_allowed(priv, ctx, &sta->ht_cap))
  		tbl->is_ht40 = 1;
  	else
  		tbl->is_ht40 = 0;
  
  	if (is_green)
  		tbl->is_SGI = 0; /*11n spec: no SGI in SISO+Greenfield*/
  
  	rs_set_expected_tpt_table(lq_sta, tbl);
  	rate = rs_get_best_rate(priv, lq_sta, tbl, rate_mask, index);
  
  	IWL_DEBUG_RATE(priv, "LQ: get best rate %d mask %X\n", rate, rate_mask);
  	if ((rate == IWL_RATE_INVALID) || !((1 << rate) & rate_mask)) {
  		IWL_DEBUG_RATE(priv, "can not switch with index %d rate mask %x\n",
  			     rate, rate_mask);
  		return -1;
  	}
  	tbl->current_rate = rate_n_flags_from_tbl(priv, tbl, rate, is_green);
  	IWL_DEBUG_RATE(priv, "LQ: Switch to new mcs %X index is green %X\n",
  		     tbl->current_rate, is_green);
  	return 0;
  }
  
  /*
   * Try to switch to new modulation mode from legacy
   */
  static int rs_move_legacy_other(struct iwl_priv *priv,
  				struct iwl_lq_sta *lq_sta,
  				struct ieee80211_conf *conf,
  				struct ieee80211_sta *sta,
  				int index)
  {
  	struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
  	struct iwl_scale_tbl_info *search_tbl =
  				&(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
  	struct iwl_rate_scale_data *window = &(tbl->win[index]);
  	u32 sz = (sizeof(struct iwl_scale_tbl_info) -
  		  (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
  	u8 start_action;
  	u8 valid_tx_ant = hw_params(priv).valid_tx_ant;
  	u8 tx_chains_num = hw_params(priv).tx_chains_num;
  	int ret = 0;
  	u8 update_search_tbl_counter = 0;
  
  	switch (priv->bt_traffic_load) {
  	case IWL_BT_COEX_TRAFFIC_LOAD_NONE:
  		/* nothing */
  		break;
  	case IWL_BT_COEX_TRAFFIC_LOAD_LOW:
  		/* avoid antenna B unless MIMO */
  		if (tbl->action == IWL_LEGACY_SWITCH_ANTENNA2)
  			tbl->action = IWL_LEGACY_SWITCH_SISO;
  		break;
  	case IWL_BT_COEX_TRAFFIC_LOAD_HIGH:
  	case IWL_BT_COEX_TRAFFIC_LOAD_CONTINUOUS:
  		/* avoid antenna B and MIMO */
  		valid_tx_ant =
  			first_antenna(hw_params(priv).valid_tx_ant);
  		if (tbl->action >= IWL_LEGACY_SWITCH_ANTENNA2 &&
  		    tbl->action != IWL_LEGACY_SWITCH_SISO)
  			tbl->action = IWL_LEGACY_SWITCH_SISO;
  		break;
  	default:
  		IWL_ERR(priv, "Invalid BT load %d", priv->bt_traffic_load);
  		break;
  	}
  
  	if (!iwl_ht_enabled(priv))
  		/* stay in Legacy */
  		tbl->action = IWL_LEGACY_SWITCH_ANTENNA1;
  	else if (iwl_tx_ant_restriction(priv) == IWL_ANT_OK_SINGLE &&
  		   tbl->action > IWL_LEGACY_SWITCH_SISO)
  		tbl->action = IWL_LEGACY_SWITCH_SISO;
  
  	/* configure as 1x1 if bt full concurrency */
  	if (priv->bt_full_concurrent) {
  		if (!iwl_ht_enabled(priv))
  			tbl->action = IWL_LEGACY_SWITCH_ANTENNA1;
  		else if (tbl->action >= IWL_LEGACY_SWITCH_ANTENNA2)
  			tbl->action = IWL_LEGACY_SWITCH_SISO;
  		valid_tx_ant =
  			first_antenna(hw_params(priv).valid_tx_ant);
  	}
  
  	start_action = tbl->action;
  	for (; ;) {
  		lq_sta->action_counter++;
  		switch (tbl->action) {
  		case IWL_LEGACY_SWITCH_ANTENNA1:
  		case IWL_LEGACY_SWITCH_ANTENNA2:
  			IWL_DEBUG_RATE(priv, "LQ: Legacy toggle Antenna\n");
  
  			if ((tbl->action == IWL_LEGACY_SWITCH_ANTENNA1 &&
  							tx_chains_num <= 1) ||
  			    (tbl->action == IWL_LEGACY_SWITCH_ANTENNA2 &&
  							tx_chains_num <= 2))
  				break;
  
  			/* Don't change antenna if success has been great */
  			if (window->success_ratio >= IWL_RS_GOOD_RATIO &&
  			    !priv->bt_full_concurrent &&
  			    priv->bt_traffic_load ==
  					IWL_BT_COEX_TRAFFIC_LOAD_NONE)
  				break;
  
  			/* Set up search table to try other antenna */
  			memcpy(search_tbl, tbl, sz);
  
  			if (rs_toggle_antenna(valid_tx_ant,
  				&search_tbl->current_rate, search_tbl)) {
  				update_search_tbl_counter = 1;
  				rs_set_expected_tpt_table(lq_sta, search_tbl);
  				goto out;
  			}
  			break;
  		case IWL_LEGACY_SWITCH_SISO:
  			IWL_DEBUG_RATE(priv, "LQ: Legacy switch to SISO\n");
  
  			/* Set up search table to try SISO */
  			memcpy(search_tbl, tbl, sz);
  			search_tbl->is_SGI = 0;
  			ret = rs_switch_to_siso(priv, lq_sta, conf, sta,
  						 search_tbl, index);
  			if (!ret) {
  				lq_sta->action_counter = 0;
  				goto out;
  			}
  
  			break;
  		case IWL_LEGACY_SWITCH_MIMO2_AB:
  		case IWL_LEGACY_SWITCH_MIMO2_AC:
  		case IWL_LEGACY_SWITCH_MIMO2_BC:
  			IWL_DEBUG_RATE(priv, "LQ: Legacy switch to MIMO2\n");
  
  			/* Set up search table to try MIMO */
  			memcpy(search_tbl, tbl, sz);
  			search_tbl->is_SGI = 0;
  
  			if (tbl->action == IWL_LEGACY_SWITCH_MIMO2_AB)
  				search_tbl->ant_type = ANT_AB;
  			else if (tbl->action == IWL_LEGACY_SWITCH_MIMO2_AC)
  				search_tbl->ant_type = ANT_AC;
  			else
  				search_tbl->ant_type = ANT_BC;
  
  			if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
  				break;
  
  			ret = rs_switch_to_mimo2(priv, lq_sta, conf, sta,
  						 search_tbl, index);
  			if (!ret) {
  				lq_sta->action_counter = 0;
  				goto out;
  			}
  			break;
  
  		case IWL_LEGACY_SWITCH_MIMO3_ABC:
  			IWL_DEBUG_RATE(priv, "LQ: Legacy switch to MIMO3\n");
  
  			/* Set up search table to try MIMO3 */
  			memcpy(search_tbl, tbl, sz);
  			search_tbl->is_SGI = 0;
  
  			search_tbl->ant_type = ANT_ABC;
  
  			if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
  				break;
  
  			ret = rs_switch_to_mimo3(priv, lq_sta, conf, sta,
  						 search_tbl, index);
  			if (!ret) {
  				lq_sta->action_counter = 0;
  				goto out;
  			}
  			break;
  		}
  		tbl->action++;
  		if (tbl->action > IWL_LEGACY_SWITCH_MIMO3_ABC)
  			tbl->action = IWL_LEGACY_SWITCH_ANTENNA1;
  
  		if (tbl->action == start_action)
  			break;
  
  	}
  	search_tbl->lq_type = LQ_NONE;
  	return 0;
  
  out:
  	lq_sta->search_better_tbl = 1;
  	tbl->action++;
  	if (tbl->action > IWL_LEGACY_SWITCH_MIMO3_ABC)
  		tbl->action = IWL_LEGACY_SWITCH_ANTENNA1;
  	if (update_search_tbl_counter)
  		search_tbl->action = tbl->action;
  	return 0;
  
  }
  
  /*
   * Try to switch to new modulation mode from SISO
   */
  static int rs_move_siso_to_other(struct iwl_priv *priv,
  				 struct iwl_lq_sta *lq_sta,
  				 struct ieee80211_conf *conf,
  				 struct ieee80211_sta *sta, int index)
  {
  	u8 is_green = lq_sta->is_green;
  	struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
  	struct iwl_scale_tbl_info *search_tbl =
  				&(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
  	struct iwl_rate_scale_data *window = &(tbl->win[index]);
  	struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
  	u32 sz = (sizeof(struct iwl_scale_tbl_info) -
  		  (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
  	u8 start_action;
  	u8 valid_tx_ant = hw_params(priv).valid_tx_ant;
  	u8 tx_chains_num = hw_params(priv).tx_chains_num;
  	u8 update_search_tbl_counter = 0;
  	int ret;
  
  	switch (priv->bt_traffic_load) {
  	case IWL_BT_COEX_TRAFFIC_LOAD_NONE:
  		/* nothing */
  		break;
  	case IWL_BT_COEX_TRAFFIC_LOAD_LOW:
  		/* avoid antenna B unless MIMO */
  		if (tbl->action == IWL_SISO_SWITCH_ANTENNA2)
  			tbl->action = IWL_SISO_SWITCH_MIMO2_AB;
  		break;
  	case IWL_BT_COEX_TRAFFIC_LOAD_HIGH:
  	case IWL_BT_COEX_TRAFFIC_LOAD_CONTINUOUS:
  		/* avoid antenna B and MIMO */
  		valid_tx_ant =
  			first_antenna(hw_params(priv).valid_tx_ant);
  		if (tbl->action != IWL_SISO_SWITCH_ANTENNA1)
  			tbl->action = IWL_SISO_SWITCH_ANTENNA1;
  		break;
  	default:
  		IWL_ERR(priv, "Invalid BT load %d", priv->bt_traffic_load);
  		break;
  	}
  
  	if (iwl_tx_ant_restriction(priv) == IWL_ANT_OK_SINGLE &&
  	    tbl->action > IWL_SISO_SWITCH_ANTENNA2) {
  		/* stay in SISO */
  		tbl->action = IWL_SISO_SWITCH_ANTENNA1;
  	}
  
  	/* configure as 1x1 if bt full concurrency */
  	if (priv->bt_full_concurrent) {
  		valid_tx_ant =
  			first_antenna(hw_params(priv).valid_tx_ant);
  		if (tbl->action >= IWL_LEGACY_SWITCH_ANTENNA2)
  			tbl->action = IWL_SISO_SWITCH_ANTENNA1;
  	}
  
  	start_action = tbl->action;
  	for (;;) {
  		lq_sta->action_counter++;
  		switch (tbl->action) {
  		case IWL_SISO_SWITCH_ANTENNA1:
  		case IWL_SISO_SWITCH_ANTENNA2:
  			IWL_DEBUG_RATE(priv, "LQ: SISO toggle Antenna\n");
  			if ((tbl->action == IWL_SISO_SWITCH_ANTENNA1 &&
  						tx_chains_num <= 1) ||
  			    (tbl->action == IWL_SISO_SWITCH_ANTENNA2 &&
  						tx_chains_num <= 2))
  				break;
  
  			if (window->success_ratio >= IWL_RS_GOOD_RATIO &&
  			    !priv->bt_full_concurrent &&
  			    priv->bt_traffic_load ==
  					IWL_BT_COEX_TRAFFIC_LOAD_NONE)
  				break;
  
  			memcpy(search_tbl, tbl, sz);
  			if (rs_toggle_antenna(valid_tx_ant,
  				       &search_tbl->current_rate, search_tbl)) {
  				update_search_tbl_counter = 1;
  				goto out;
  			}
  			break;
  		case IWL_SISO_SWITCH_MIMO2_AB:
  		case IWL_SISO_SWITCH_MIMO2_AC:
  		case IWL_SISO_SWITCH_MIMO2_BC:
  			IWL_DEBUG_RATE(priv, "LQ: SISO switch to MIMO2\n");
  			memcpy(search_tbl, tbl, sz);
  			search_tbl->is_SGI = 0;
  
  			if (tbl->action == IWL_SISO_SWITCH_MIMO2_AB)
  				search_tbl->ant_type = ANT_AB;
  			else if (tbl->action == IWL_SISO_SWITCH_MIMO2_AC)
  				search_tbl->ant_type = ANT_AC;
  			else
  				search_tbl->ant_type = ANT_BC;
  
  			if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
  				break;
  
  			ret = rs_switch_to_mimo2(priv, lq_sta, conf, sta,
  						 search_tbl, index);
  			if (!ret)
  				goto out;
  			break;
  		case IWL_SISO_SWITCH_GI:
  			if (!tbl->is_ht40 && !(ht_cap->cap &
  						IEEE80211_HT_CAP_SGI_20))
  				break;
  			if (tbl->is_ht40 && !(ht_cap->cap &
  						IEEE80211_HT_CAP_SGI_40))
  				break;
  
  			IWL_DEBUG_RATE(priv, "LQ: SISO toggle SGI/NGI\n");
  
  			memcpy(search_tbl, tbl, sz);
  			if (is_green) {
  				if (!tbl->is_SGI)
  					break;
  				else
  					IWL_ERR(priv,
  						"SGI was set in GF+SISO\n");
  			}
  			search_tbl->is_SGI = !tbl->is_SGI;
  			rs_set_expected_tpt_table(lq_sta, search_tbl);
  			if (tbl->is_SGI) {
  				s32 tpt = lq_sta->last_tpt / 100;
  				if (tpt >= search_tbl->expected_tpt[index])
  					break;
  			}
  			search_tbl->current_rate =
  				rate_n_flags_from_tbl(priv, search_tbl,
  						      index, is_green);
  			update_search_tbl_counter = 1;
  			goto out;
  		case IWL_SISO_SWITCH_MIMO3_ABC:
  			IWL_DEBUG_RATE(priv, "LQ: SISO switch to MIMO3\n");
  			memcpy(search_tbl, tbl, sz);
  			search_tbl->is_SGI = 0;
  			search_tbl->ant_type = ANT_ABC;
  
  			if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
  				break;
  
  			ret = rs_switch_to_mimo3(priv, lq_sta, conf, sta,
  						 search_tbl, index);
  			if (!ret)
  				goto out;
  			break;
  		}
  		tbl->action++;
  		if (tbl->action > IWL_LEGACY_SWITCH_MIMO3_ABC)
  			tbl->action = IWL_SISO_SWITCH_ANTENNA1;
  
  		if (tbl->action == start_action)
  			break;
  	}
  	search_tbl->lq_type = LQ_NONE;
  	return 0;
  
   out:
  	lq_sta->search_better_tbl = 1;
  	tbl->action++;
  	if (tbl->action > IWL_SISO_SWITCH_MIMO3_ABC)
  		tbl->action = IWL_SISO_SWITCH_ANTENNA1;
  	if (update_search_tbl_counter)
  		search_tbl->action = tbl->action;
  
  	return 0;
  }
  
  /*
   * Try to switch to new modulation mode from MIMO2
   */
  static int rs_move_mimo2_to_other(struct iwl_priv *priv,
  				 struct iwl_lq_sta *lq_sta,
  				 struct ieee80211_conf *conf,
  				 struct ieee80211_sta *sta, int index)
  {
  	s8 is_green = lq_sta->is_green;
  	struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
  	struct iwl_scale_tbl_info *search_tbl =
  				&(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
  	struct iwl_rate_scale_data *window = &(tbl->win[index]);
  	struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
  	u32 sz = (sizeof(struct iwl_scale_tbl_info) -
  		  (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
  	u8 start_action;
  	u8 valid_tx_ant = hw_params(priv).valid_tx_ant;
  	u8 tx_chains_num = hw_params(priv).tx_chains_num;
  	u8 update_search_tbl_counter = 0;
  	int ret;
  
  	switch (priv->bt_traffic_load) {
  	case IWL_BT_COEX_TRAFFIC_LOAD_NONE:
  		/* nothing */
  		break;
  	case IWL_BT_COEX_TRAFFIC_LOAD_HIGH:
  	case IWL_BT_COEX_TRAFFIC_LOAD_CONTINUOUS:
  		/* avoid antenna B and MIMO */
  		if (tbl->action != IWL_MIMO2_SWITCH_SISO_A)
  			tbl->action = IWL_MIMO2_SWITCH_SISO_A;
  		break;
  	case IWL_BT_COEX_TRAFFIC_LOAD_LOW:
  		/* avoid antenna B unless MIMO */
  		if (tbl->action == IWL_MIMO2_SWITCH_SISO_B ||
  		    tbl->action == IWL_MIMO2_SWITCH_SISO_C)
  			tbl->action = IWL_MIMO2_SWITCH_SISO_A;
  		break;
  	default:
  		IWL_ERR(priv, "Invalid BT load %d", priv->bt_traffic_load);
  		break;
  	}
  
  	if ((iwl_tx_ant_restriction(priv) == IWL_ANT_OK_SINGLE) &&
  	    (tbl->action < IWL_MIMO2_SWITCH_SISO_A ||
  	     tbl->action > IWL_MIMO2_SWITCH_SISO_C)) {
  		/* switch in SISO */
  		tbl->action = IWL_MIMO2_SWITCH_SISO_A;
  	}
  
  	/* configure as 1x1 if bt full concurrency */
  	if (priv->bt_full_concurrent &&
  	    (tbl->action < IWL_MIMO2_SWITCH_SISO_A ||
  	     tbl->action > IWL_MIMO2_SWITCH_SISO_C))
  		tbl->action = IWL_MIMO2_SWITCH_SISO_A;
  
  	start_action = tbl->action;
  	for (;;) {
  		lq_sta->action_counter++;
  		switch (tbl->action) {
  		case IWL_MIMO2_SWITCH_ANTENNA1:
  		case IWL_MIMO2_SWITCH_ANTENNA2:
  			IWL_DEBUG_RATE(priv, "LQ: MIMO2 toggle Antennas\n");
  
  			if (tx_chains_num <= 2)
  				break;
  
  			if (window->success_ratio >= IWL_RS_GOOD_RATIO)
  				break;
  
  			memcpy(search_tbl, tbl, sz);
  			if (rs_toggle_antenna(valid_tx_ant,
  				       &search_tbl->current_rate, search_tbl)) {
  				update_search_tbl_counter = 1;
  				goto out;
  			}
  			break;
  		case IWL_MIMO2_SWITCH_SISO_A:
  		case IWL_MIMO2_SWITCH_SISO_B:
  		case IWL_MIMO2_SWITCH_SISO_C:
  			IWL_DEBUG_RATE(priv, "LQ: MIMO2 switch to SISO\n");
  
  			/* Set up new search table for SISO */
  			memcpy(search_tbl, tbl, sz);
  
  			if (tbl->action == IWL_MIMO2_SWITCH_SISO_A)
  				search_tbl->ant_type = ANT_A;
  			else if (tbl->action == IWL_MIMO2_SWITCH_SISO_B)
  				search_tbl->ant_type = ANT_B;
  			else
  				search_tbl->ant_type = ANT_C;
  
  			if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
  				break;
  
  			ret = rs_switch_to_siso(priv, lq_sta, conf, sta,
  						 search_tbl, index);
  			if (!ret)
  				goto out;
  
  			break;
  
  		case IWL_MIMO2_SWITCH_GI:
  			if (!tbl->is_ht40 && !(ht_cap->cap &
  						IEEE80211_HT_CAP_SGI_20))
  				break;
  			if (tbl->is_ht40 && !(ht_cap->cap &
  						IEEE80211_HT_CAP_SGI_40))
  				break;
  
  			IWL_DEBUG_RATE(priv, "LQ: MIMO2 toggle SGI/NGI\n");
  
  			/* Set up new search table for MIMO2 */
  			memcpy(search_tbl, tbl, sz);
  			search_tbl->is_SGI = !tbl->is_SGI;
  			rs_set_expected_tpt_table(lq_sta, search_tbl);
  			/*
  			 * If active table already uses the fastest possible
  			 * modulation (dual stream with short guard interval),
  			 * and it's working well, there's no need to look
  			 * for a better type of modulation!
  			 */
  			if (tbl->is_SGI) {
  				s32 tpt = lq_sta->last_tpt / 100;
  				if (tpt >= search_tbl->expected_tpt[index])
  					break;
  			}
  			search_tbl->current_rate =
  				rate_n_flags_from_tbl(priv, search_tbl,
  						      index, is_green);
  			update_search_tbl_counter = 1;
  			goto out;
  
  		case IWL_MIMO2_SWITCH_MIMO3_ABC:
  			IWL_DEBUG_RATE(priv, "LQ: MIMO2 switch to MIMO3\n");
  			memcpy(search_tbl, tbl, sz);
  			search_tbl->is_SGI = 0;
  			search_tbl->ant_type = ANT_ABC;
  
  			if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
  				break;
  
  			ret = rs_switch_to_mimo3(priv, lq_sta, conf, sta,
  						 search_tbl, index);
  			if (!ret)
  				goto out;
  
  			break;
  		}
  		tbl->action++;
  		if (tbl->action > IWL_MIMO2_SWITCH_MIMO3_ABC)
  			tbl->action = IWL_MIMO2_SWITCH_ANTENNA1;
  
  		if (tbl->action == start_action)
  			break;
  	}
  	search_tbl->lq_type = LQ_NONE;
  	return 0;
   out:
  	lq_sta->search_better_tbl = 1;
  	tbl->action++;
  	if (tbl->action > IWL_MIMO2_SWITCH_MIMO3_ABC)
  		tbl->action = IWL_MIMO2_SWITCH_ANTENNA1;
  	if (update_search_tbl_counter)
  		search_tbl->action = tbl->action;
  
  	return 0;
  
  }
  
  /*
   * Try to switch to new modulation mode from MIMO3
   */
  static int rs_move_mimo3_to_other(struct iwl_priv *priv,
  				 struct iwl_lq_sta *lq_sta,
  				 struct ieee80211_conf *conf,
  				 struct ieee80211_sta *sta, int index)
  {
  	s8 is_green = lq_sta->is_green;
  	struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
  	struct iwl_scale_tbl_info *search_tbl =
  				&(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
  	struct iwl_rate_scale_data *window = &(tbl->win[index]);
  	struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
  	u32 sz = (sizeof(struct iwl_scale_tbl_info) -
  		  (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
  	u8 start_action;
  	u8 valid_tx_ant = hw_params(priv).valid_tx_ant;
  	u8 tx_chains_num = hw_params(priv).tx_chains_num;
  	int ret;
  	u8 update_search_tbl_counter = 0;
  
  	switch (priv->bt_traffic_load) {
  	case IWL_BT_COEX_TRAFFIC_LOAD_NONE:
  		/* nothing */
  		break;
  	case IWL_BT_COEX_TRAFFIC_LOAD_HIGH:
  	case IWL_BT_COEX_TRAFFIC_LOAD_CONTINUOUS:
  		/* avoid antenna B and MIMO */
  		if (tbl->action != IWL_MIMO3_SWITCH_SISO_A)
  			tbl->action = IWL_MIMO3_SWITCH_SISO_A;
  		break;
  	case IWL_BT_COEX_TRAFFIC_LOAD_LOW:
  		/* avoid antenna B unless MIMO */
  		if (tbl->action == IWL_MIMO3_SWITCH_SISO_B ||
  		    tbl->action == IWL_MIMO3_SWITCH_SISO_C)
  			tbl->action = IWL_MIMO3_SWITCH_SISO_A;
  		break;
  	default:
  		IWL_ERR(priv, "Invalid BT load %d", priv->bt_traffic_load);
  		break;
  	}
  
  	if ((iwl_tx_ant_restriction(priv) == IWL_ANT_OK_SINGLE) &&
  	    (tbl->action < IWL_MIMO3_SWITCH_SISO_A ||
  	     tbl->action > IWL_MIMO3_SWITCH_SISO_C)) {
  		/* switch in SISO */
  		tbl->action = IWL_MIMO3_SWITCH_SISO_A;
  	}
  
  	/* configure as 1x1 if bt full concurrency */
  	if (priv->bt_full_concurrent &&
  	    (tbl->action < IWL_MIMO3_SWITCH_SISO_A ||
  	     tbl->action > IWL_MIMO3_SWITCH_SISO_C))
  		tbl->action = IWL_MIMO3_SWITCH_SISO_A;
  
  	start_action = tbl->action;
  	for (;;) {
  		lq_sta->action_counter++;
  		switch (tbl->action) {
  		case IWL_MIMO3_SWITCH_ANTENNA1:
  		case IWL_MIMO3_SWITCH_ANTENNA2:
  			IWL_DEBUG_RATE(priv, "LQ: MIMO3 toggle Antennas\n");
  
  			if (tx_chains_num <= 3)
  				break;
  
  			if (window->success_ratio >= IWL_RS_GOOD_RATIO)
  				break;
  
  			memcpy(search_tbl, tbl, sz);
  			if (rs_toggle_antenna(valid_tx_ant,
  				       &search_tbl->current_rate, search_tbl))
  				goto out;
  			break;
  		case IWL_MIMO3_SWITCH_SISO_A:
  		case IWL_MIMO3_SWITCH_SISO_B:
  		case IWL_MIMO3_SWITCH_SISO_C:
  			IWL_DEBUG_RATE(priv, "LQ: MIMO3 switch to SISO\n");
  
  			/* Set up new search table for SISO */
  			memcpy(search_tbl, tbl, sz);
  
  			if (tbl->action == IWL_MIMO3_SWITCH_SISO_A)
  				search_tbl->ant_type = ANT_A;
  			else if (tbl->action == IWL_MIMO3_SWITCH_SISO_B)
  				search_tbl->ant_type = ANT_B;
  			else
  				search_tbl->ant_type = ANT_C;
  
  			if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
  				break;
  
  			ret = rs_switch_to_siso(priv, lq_sta, conf, sta,
  						 search_tbl, index);
  			if (!ret)
  				goto out;
  
  			break;
  
  		case IWL_MIMO3_SWITCH_MIMO2_AB:
  		case IWL_MIMO3_SWITCH_MIMO2_AC:
  		case IWL_MIMO3_SWITCH_MIMO2_BC:
  			IWL_DEBUG_RATE(priv, "LQ: MIMO3 switch to MIMO2\n");
  
  			memcpy(search_tbl, tbl, sz);
  			search_tbl->is_SGI = 0;
  			if (tbl->action == IWL_MIMO3_SWITCH_MIMO2_AB)
  				search_tbl->ant_type = ANT_AB;
  			else if (tbl->action == IWL_MIMO3_SWITCH_MIMO2_AC)
  				search_tbl->ant_type = ANT_AC;
  			else
  				search_tbl->ant_type = ANT_BC;
  
  			if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
  				break;
  
  			ret = rs_switch_to_mimo2(priv, lq_sta, conf, sta,
  						 search_tbl, index);
  			if (!ret)
  				goto out;
  
  			break;
  
  		case IWL_MIMO3_SWITCH_GI:
  			if (!tbl->is_ht40 && !(ht_cap->cap &
  						IEEE80211_HT_CAP_SGI_20))
  				break;
  			if (tbl->is_ht40 && !(ht_cap->cap &
  						IEEE80211_HT_CAP_SGI_40))
  				break;
  
  			IWL_DEBUG_RATE(priv, "LQ: MIMO3 toggle SGI/NGI\n");
  
  			/* Set up new search table for MIMO */
  			memcpy(search_tbl, tbl, sz);
  			search_tbl->is_SGI = !tbl->is_SGI;
  			rs_set_expected_tpt_table(lq_sta, search_tbl);
  			/*
  			 * If active table already uses the fastest possible
  			 * modulation (dual stream with short guard interval),
  			 * and it's working well, there's no need to look
  			 * for a better type of modulation!
  			 */
  			if (tbl->is_SGI) {
  				s32 tpt = lq_sta->last_tpt / 100;
  				if (tpt >= search_tbl->expected_tpt[index])
  					break;
  			}
  			search_tbl->current_rate =
  				rate_n_flags_from_tbl(priv, search_tbl,
  						      index, is_green);
  			update_search_tbl_counter = 1;
  			goto out;
  		}
  		tbl->action++;
  		if (tbl->action > IWL_MIMO3_SWITCH_GI)
  			tbl->action = IWL_MIMO3_SWITCH_ANTENNA1;
  
  		if (tbl->action == start_action)
  			break;
  	}
  	search_tbl->lq_type = LQ_NONE;
  	return 0;
   out:
  	lq_sta->search_better_tbl = 1;
  	tbl->action++;
  	if (tbl->action > IWL_MIMO3_SWITCH_GI)
  		tbl->action = IWL_MIMO3_SWITCH_ANTENNA1;
  	if (update_search_tbl_counter)
  		search_tbl->action = tbl->action;
  
  	return 0;
  
  }
  
  /*
   * Check whether we should continue using same modulation mode, or
   * begin search for a new mode, based on:
   * 1) # tx successes or failures while using this mode
   * 2) # times calling this function
   * 3) elapsed time in this mode (not used, for now)
   */
  static void rs_stay_in_table(struct iwl_lq_sta *lq_sta, bool force_search)
  {
  	struct iwl_scale_tbl_info *tbl;
  	int i;
  	int active_tbl;
  	int flush_interval_passed = 0;
  	struct iwl_priv *priv;
  
  	priv = lq_sta->drv;
  	active_tbl = lq_sta->active_tbl;
  
  	tbl = &(lq_sta->lq_info[active_tbl]);
  
  	/* If we've been disallowing search, see if we should now allow it */
  	if (lq_sta->stay_in_tbl) {
  
  		/* Elapsed time using current modulation mode */
  		if (lq_sta->flush_timer)
  			flush_interval_passed =
  			time_after(jiffies,
  					(unsigned long)(lq_sta->flush_timer +
  					IWL_RATE_SCALE_FLUSH_INTVL));
  
  		/*
  		 * Check if we should allow search for new modulation mode.
  		 * If many frames have failed or succeeded, or we've used
  		 * this same modulation for a long time, allow search, and
  		 * reset history stats that keep track of whether we should
  		 * allow a new search.  Also (below) reset all bitmaps and
  		 * stats in active history.
  		 */
  		if (force_search ||
  		    (lq_sta->total_failed > lq_sta->max_failure_limit) ||
  		    (lq_sta->total_success > lq_sta->max_success_limit) ||
  		    ((!lq_sta->search_better_tbl) && (lq_sta->flush_timer)
  		     && (flush_interval_passed))) {
  			IWL_DEBUG_RATE(priv, "LQ: stay is expired %d %d %d\n:",
  				     lq_sta->total_failed,
  				     lq_sta->total_success,
  				     flush_interval_passed);
  
  			/* Allow search for new mode */
  			lq_sta->stay_in_tbl = 0;	/* only place reset */
  			lq_sta->total_failed = 0;
  			lq_sta->total_success = 0;
  			lq_sta->flush_timer = 0;
  
  		/*
  		 * Else if we've used this modulation mode enough repetitions
  		 * (regardless of elapsed time or success/failure), reset
  		 * history bitmaps and rate-specific stats for all rates in
  		 * active table.
  		 */
  		} else {
  			lq_sta->table_count++;
  			if (lq_sta->table_count >=
  			    lq_sta->table_count_limit) {
  				lq_sta->table_count = 0;
  
  				IWL_DEBUG_RATE(priv, "LQ: stay in table clear win\n");
  				for (i = 0; i < IWL_RATE_COUNT; i++)
  					rs_rate_scale_clear_window(
  						&(tbl->win[i]));
  			}
  		}
  
  		/* If transitioning to allow "search", reset all history
  		 * bitmaps and stats in active table (this will become the new
  		 * "search" table). */
  		if (!lq_sta->stay_in_tbl) {
  			for (i = 0; i < IWL_RATE_COUNT; i++)
  				rs_rate_scale_clear_window(&(tbl->win[i]));
  		}
  	}
  }
  
  /*
   * setup rate table in uCode
   */
  static void rs_update_rate_tbl(struct iwl_priv *priv,
  			       struct iwl_rxon_context *ctx,
  			       struct iwl_lq_sta *lq_sta,
  			       struct iwl_scale_tbl_info *tbl,
  			       int index, u8 is_green)
  {
  	u32 rate;
  
  	/* Update uCode's rate table. */
  	rate = rate_n_flags_from_tbl(priv, tbl, index, is_green);
  	rs_fill_link_cmd(priv, lq_sta, rate);
  	iwl_send_lq_cmd(priv, ctx, &lq_sta->lq, CMD_ASYNC, false);
  }
  
  /*
   * Do rate scaling and search for new modulation mode.
   */
  static void rs_rate_scale_perform(struct iwl_priv *priv,
  				  struct sk_buff *skb,
  				  struct ieee80211_sta *sta,
  				  struct iwl_lq_sta *lq_sta)
  {
  	struct ieee80211_hw *hw = priv->hw;
  	struct ieee80211_conf *conf = &hw->conf;
  	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
  	int low = IWL_RATE_INVALID;
  	int high = IWL_RATE_INVALID;
  	int index;
  	int i;
  	struct iwl_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;
  	u16 rate_mask;
  	u8 update_lq = 0;
  	struct iwl_scale_tbl_info *tbl, *tbl1;
  	u16 rate_scale_index_msk = 0;
  	u8 is_green = 0;
  	u8 active_tbl = 0;
  	u8 done_search = 0;
  	u16 high_low;
  	s32 sr;
  	u8 tid = IWL_MAX_TID_COUNT;
  	struct iwl_tid_data *tid_data;
  	struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
  	struct iwl_rxon_context *ctx = sta_priv->ctx;
  
  	IWL_DEBUG_RATE(priv, "rate scale calculate new rate for skb\n");
  
  	/* Send management frames and NO_ACK data using lowest rate. */
  	/* TODO: this could probably be improved.. */
  	if (!ieee80211_is_data(hdr->frame_control) ||
  	    info->flags & IEEE80211_TX_CTL_NO_ACK)
  		return;
  
  	lq_sta->supp_rates = sta->supp_rates[lq_sta->band];
  
  	tid = rs_tl_add_packet(lq_sta, hdr);
  	if ((tid != IWL_MAX_TID_COUNT) &&
  	    (lq_sta->tx_agg_tid_en & (1 << tid))) {
  		tid_data = &priv->shrd->tid_data[lq_sta->lq.sta_id][tid];
  		if (tid_data->agg.state == IWL_AGG_OFF)
  			lq_sta->is_agg = 0;
  		else
  			lq_sta->is_agg = 1;
  	} else
  		lq_sta->is_agg = 0;
  
  	/*
  	 * Select rate-scale / modulation-mode table to work with in
  	 * the rest of this function:  "search" if searching for better
  	 * modulation mode, or "active" if doing rate scaling within a mode.
  	 */
  	if (!lq_sta->search_better_tbl)
  		active_tbl = lq_sta->active_tbl;
  	else
  		active_tbl = 1 - lq_sta->active_tbl;
  
  	tbl = &(lq_sta->lq_info[active_tbl]);
  	if (is_legacy(tbl->lq_type))
  		lq_sta->is_green = 0;
  	else
  		lq_sta->is_green = rs_use_green(sta);
  	is_green = lq_sta->is_green;
  
  	/* current tx rate */
  	index = lq_sta->last_txrate_idx;
  
  	IWL_DEBUG_RATE(priv, "Rate scale index %d for type %d\n", index,
  		       tbl->lq_type);
  
  	/* rates available for this association, and for modulation mode */
  	rate_mask = rs_get_supported_rates(lq_sta, hdr, tbl->lq_type);
  
  	IWL_DEBUG_RATE(priv, "mask 0x%04X\n", rate_mask);
  
  	/* mask with station rate restriction */
  	if (is_legacy(tbl->lq_type)) {
  		if (lq_sta->band == IEEE80211_BAND_5GHZ)
  			/* supp_rates has no CCK bits in A mode */
  			rate_scale_index_msk = (u16) (rate_mask &
  				(lq_sta->supp_rates << IWL_FIRST_OFDM_RATE));
  		else
  			rate_scale_index_msk = (u16) (rate_mask &
  						      lq_sta->supp_rates);
  
  	} else
  		rate_scale_index_msk = rate_mask;
  
  	if (!rate_scale_index_msk)
  		rate_scale_index_msk = rate_mask;
  
  	if (!((1 << index) & rate_scale_index_msk)) {
  		IWL_ERR(priv, "Current Rate is not valid\n");
  		if (lq_sta->search_better_tbl) {
  			/* revert to active table if search table is not valid*/
  			tbl->lq_type = LQ_NONE;
  			lq_sta->search_better_tbl = 0;
  			tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
  			/* get "active" rate info */
  			index = iwl_hwrate_to_plcp_idx(tbl->current_rate);
  			rs_update_rate_tbl(priv, ctx, lq_sta, tbl,
  					   index, is_green);
  		}
  		return;
  	}
  
  	/* Get expected throughput table and history window for current rate */
  	if (!tbl->expected_tpt) {
  		IWL_ERR(priv, "tbl->expected_tpt is NULL\n");
  		return;
  	}
  
  	/* force user max rate if set by user */
  	if ((lq_sta->max_rate_idx != -1) &&
  	    (lq_sta->max_rate_idx < index)) {
  		index = lq_sta->max_rate_idx;
  		update_lq = 1;
  		window = &(tbl->win[index]);
  		goto lq_update;
  	}
  
  	window = &(tbl->win[index]);
  
  	/*
  	 * If there is not enough history to calculate actual average
  	 * throughput, keep analyzing results of more tx frames, without
  	 * changing rate or mode (bypass most of the rest of this function).
  	 * Set up new rate table in uCode only if old rate is not supported
  	 * in current association (use new rate found above).
  	 */
  	fail_count = window->counter - window->success_counter;
  	if ((fail_count < IWL_RATE_MIN_FAILURE_TH) &&
  			(window->success_counter < IWL_RATE_MIN_SUCCESS_TH)) {
  		IWL_DEBUG_RATE(priv, "LQ: still below TH. succ=%d total=%d "
  			       "for index %d\n",
  			       window->success_counter, window->counter, index);
  
  		/* Can't calculate this yet; not enough history */
  		window->average_tpt = IWL_INVALID_VALUE;
  
  		/* Should we stay with this modulation mode,
  		 * or search for a new one? */
  		rs_stay_in_table(lq_sta, false);
  
  		goto out;
  	}
  	/* Else we have enough samples; calculate estimate of
  	 * actual average throughput */
  	if (window->average_tpt != ((window->success_ratio *
  			tbl->expected_tpt[index] + 64) / 128)) {
  		IWL_ERR(priv, "expected_tpt should have been calculated by now\n");
  		window->average_tpt = ((window->success_ratio *
  					tbl->expected_tpt[index] + 64) / 128);
  	}
  
  	/* If we are searching for better modulation mode, check success. */
  	if (lq_sta->search_better_tbl &&
  	    (iwl_tx_ant_restriction(priv) == IWL_ANT_OK_MULTI)) {
  		/* If good success, continue using the "search" mode;
  		 * no need to send new link quality command, since we're
  		 * continuing to use the setup that we've been trying. */
  		if (window->average_tpt > lq_sta->last_tpt) {
  
  			IWL_DEBUG_RATE(priv, "LQ: SWITCHING TO NEW TABLE "
  					"suc=%d cur-tpt=%d old-tpt=%d\n",
  					window->success_ratio,
  					window->average_tpt,
  					lq_sta->last_tpt);
  
  			if (!is_legacy(tbl->lq_type))
  				lq_sta->enable_counter = 1;
  
  			/* Swap tables; "search" becomes "active" */
  			lq_sta->active_tbl = active_tbl;
  			current_tpt = window->average_tpt;
  
  		/* Else poor success; go back to mode in "active" table */
  		} else {
  
  			IWL_DEBUG_RATE(priv, "LQ: GOING BACK TO THE OLD TABLE "
  					"suc=%d cur-tpt=%d old-tpt=%d\n",
  					window->success_ratio,
  					window->average_tpt,
  					lq_sta->last_tpt);
  
  			/* Nullify "search" table */
  			tbl->lq_type = LQ_NONE;
  
  			/* Revert to "active" table */
  			active_tbl = lq_sta->active_tbl;
  			tbl = &(lq_sta->lq_info[active_tbl]);
  
  			/* Revert to "active" rate and throughput info */
  			index = iwl_hwrate_to_plcp_idx(tbl->current_rate);
  			current_tpt = lq_sta->last_tpt;
  
  			/* Need to set up a new rate table in uCode */
  			update_lq = 1;
  		}
  
  		/* Either way, we've made a decision; modulation mode
  		 * search is done, allow rate adjustment next time. */
  		lq_sta->search_better_tbl = 0;
  		done_search = 1;	/* Don't switch modes below! */
  		goto lq_update;
  	}
  
  	/* (Else) not in search of better modulation mode, try for better
  	 * starting rate, while staying in this mode. */
  	high_low = rs_get_adjacent_rate(priv, index, rate_scale_index_msk,
  					tbl->lq_type);
  	low = high_low & 0xff;
  	high = (high_low >> 8) & 0xff;
  
  	/* If user set max rate, dont allow higher than user constrain */
  	if ((lq_sta->max_rate_idx != -1) &&
  	    (lq_sta->max_rate_idx < high))
  		high = IWL_RATE_INVALID;
  
  	sr = window->success_ratio;
  
  	/* Collect measured throughputs for current and adjacent rates */
  	current_tpt = window->average_tpt;
  	if (low != IWL_RATE_INVALID)
  		low_tpt = tbl->win[low].average_tpt;
  	if (high != IWL_RATE_INVALID)
  		high_tpt = tbl->win[high].average_tpt;
  
  	scale_action = 0;
  
  	/* Too many failures, decrease rate */
  	if ((sr <= IWL_RATE_DECREASE_TH) || (current_tpt == 0)) {
  		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 && sr >= 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))
  		scale_action = 0;
  
  	/* At least one adjacent rate's throughput is measured,
  	 * and may have better performance. */
  	else {
  		/* Higher adjacent rate's throughput is measured */
  		if (high_tpt != IWL_INVALID_VALUE) {
  			/* Higher rate has better throughput */
  			if (high_tpt > current_tpt &&
  					sr >= IWL_RATE_INCREASE_TH) {
  				scale_action = 1;
  			} else {
  				scale_action = 0;
  			}
  
  		/* Lower adjacent rate's throughput is measured */
  		} else if (low_tpt != IWL_INVALID_VALUE) {
  			/* Lower rate has better throughput */
  			if (low_tpt > current_tpt) {
  				IWL_DEBUG_RATE(priv,
  				    "decrease rate because of low tpt\n");
  				scale_action = -1;
  			} else if (sr >= IWL_RATE_INCREASE_TH) {
  				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) &&
  		    ((sr > IWL_RATE_HIGH_TH) ||
  		     (current_tpt > (100 * tbl->expected_tpt[low]))))
  		scale_action = 0;
  	if (!iwl_ht_enabled(priv) && !is_legacy(tbl->lq_type))
  		scale_action = -1;
  	if (iwl_tx_ant_restriction(priv) != IWL_ANT_OK_MULTI &&
  		(is_mimo2(tbl->lq_type) || is_mimo3(tbl->lq_type)))
  		scale_action = -1;
  
  	if ((priv->bt_traffic_load >= IWL_BT_COEX_TRAFFIC_LOAD_HIGH) &&
  	     (is_mimo2(tbl->lq_type) || is_mimo3(tbl->lq_type))) {
  		if (lq_sta->last_bt_traffic > priv->bt_traffic_load) {
  			/*
  			 * don't set scale_action, don't want to scale up if
  			 * the rate scale doesn't otherwise think that is a
  			 * good idea.
  			 */
  		} else if (lq_sta->last_bt_traffic <= priv->bt_traffic_load) {
  			scale_action = -1;
  		}
  	}
  	lq_sta->last_bt_traffic = priv->bt_traffic_load;
  
  	if ((priv->bt_traffic_load >= IWL_BT_COEX_TRAFFIC_LOAD_HIGH) &&
  	     (is_mimo2(tbl->lq_type) || is_mimo3(tbl->lq_type))) {
  		/* search for a new modulation */
  		rs_stay_in_table(lq_sta, true);
  		goto lq_update;
  	}
  
  	switch (scale_action) {
  	case -1:
  		/* Decrease starting rate, update uCode's rate table */
  		if (low != IWL_RATE_INVALID) {
  			update_lq = 1;
  			index = low;
  		}
  
  		break;
  	case 1:
  		/* Increase starting rate, update uCode's rate table */
  		if (high != IWL_RATE_INVALID) {
  			update_lq = 1;
  			index = high;
  		}
  
  		break;
  	case 0:
  		/* No change */
  	default:
  		break;
  	}
  
  	IWL_DEBUG_RATE(priv, "choose rate scale index %d action %d low %d "
  		    "high %d type %d\n",
  		     index, scale_action, low, high, tbl->lq_type);
  
  lq_update:
  	/* Replace uCode's rate table for the destination station. */
  	if (update_lq)
  		rs_update_rate_tbl(priv, ctx, lq_sta, tbl, index, is_green);
  
  	if (iwl_tx_ant_restriction(priv) == IWL_ANT_OK_MULTI) {
  		/* Should we stay with this modulation mode,
  		 * or search for a new one? */
  	  rs_stay_in_table(lq_sta, false);
  	}
  	/*
  	 * Search for new modulation mode if we're:
  	 * 1)  Not changing rates right now
  	 * 2)  Not just finishing up a search
  	 * 3)  Allowing a new search
  	 */
  	if (!update_lq && !done_search && !lq_sta->stay_in_tbl && window->counter) {
  		/* Save current throughput to compare with "search" throughput*/
  		lq_sta->last_tpt = current_tpt;
  
  		/* Select a new "search" modulation mode to try.
  		 * If one is found, set up the new "search" table. */
  		if (is_legacy(tbl->lq_type))
  			rs_move_legacy_other(priv, lq_sta, conf, sta, index);
  		else if (is_siso(tbl->lq_type))
  			rs_move_siso_to_other(priv, lq_sta, conf, sta, index);
  		else if (is_mimo2(tbl->lq_type))
  			rs_move_mimo2_to_other(priv, lq_sta, conf, sta, index);
  		else
  			rs_move_mimo3_to_other(priv, lq_sta, conf, sta, index);
  
  		/* If new "search" mode was selected, set up in uCode table */
  		if (lq_sta->search_better_tbl) {
  			/* Access the "search" table, clear its history. */
  			tbl = &(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
  			for (i = 0; i < IWL_RATE_COUNT; i++)
  				rs_rate_scale_clear_window(&(tbl->win[i]));
  
  			/* Use new "search" start rate */
  			index = iwl_hwrate_to_plcp_idx(tbl->current_rate);
  
  			IWL_DEBUG_RATE(priv, "Switch current  mcs: %X index: %d\n",
  				     tbl->current_rate, index);
  			rs_fill_link_cmd(priv, lq_sta, tbl->current_rate);
  			iwl_send_lq_cmd(priv, ctx, &lq_sta->lq, CMD_ASYNC, false);
  		} else
  			done_search = 1;
  	}
  
  	if (done_search && !lq_sta->stay_in_tbl) {
  		/* If the "active" (non-search) mode was legacy,
  		 * and we've tried switching antennas,
  		 * but we haven't been able to try HT modes (not available),
  		 * stay with best antenna legacy modulation for a while
  		 * before next round of mode comparisons. */
  		tbl1 = &(lq_sta->lq_info[lq_sta->active_tbl]);
  		if (is_legacy(tbl1->lq_type) && !conf_is_ht(conf) &&
  		    lq_sta->action_counter > tbl1->max_search) {
  			IWL_DEBUG_RATE(priv, "LQ: STAY in legacy table\n");
  			rs_set_stay_in_table(priv, 1, lq_sta);
  		}
  
  		/* If we're in an HT mode, and all 3 mode switch actions
  		 * have been tried and compared, stay in this best modulation
  		 * mode for a while before next round of mode comparisons. */
  		if (lq_sta->enable_counter &&
  		    (lq_sta->action_counter >= tbl1->max_search) &&
  		    iwl_ht_enabled(priv)) {
  			if ((lq_sta->last_tpt > IWL_AGG_TPT_THREHOLD) &&
  			    (lq_sta->tx_agg_tid_en & (1 << tid)) &&
  			    (tid != IWL_MAX_TID_COUNT)) {
  				u8 sta_id = lq_sta->lq.sta_id;
  				tid_data =
  				   &priv->shrd->tid_data[sta_id][tid];
  				if (tid_data->agg.state == IWL_AGG_OFF) {
  					IWL_DEBUG_RATE(priv,
  						       "try to aggregate tid %d\n",
  						       tid);
  					rs_tl_turn_on_agg(priv, tid,
  							  lq_sta, sta);
  				}
  			}
  			rs_set_stay_in_table(priv, 0, lq_sta);
  		}
  	}
  
  out:
  	tbl->current_rate = rate_n_flags_from_tbl(priv, tbl, index, is_green);
  	lq_sta->last_txrate_idx = index;
  }
  
  /**
   * rs_initialize_lq - Initialize a station's hardware rate table
   *
   * The uCode's station table contains a table of fallback rates
   * for automatic fallback during transmission.
   *
   * NOTE: This sets up a default set of values.  These will be replaced later
   *       if the driver's iwl-agn-rs rate scaling algorithm is used, instead of
   *       rc80211_simple.
   *
   * NOTE: Run REPLY_ADD_STA command to set up station table entry, before
   *       calling this function (which runs REPLY_TX_LINK_QUALITY_CMD,
   *       which requires station table entry to exist).
   */
  static void rs_initialize_lq(struct iwl_priv *priv,
  			     struct ieee80211_conf *conf,
  			     struct ieee80211_sta *sta,
  			     struct iwl_lq_sta *lq_sta)
  {
  	struct iwl_scale_tbl_info *tbl;
  	int rate_idx;
  	int i;
  	u32 rate;
  	u8 use_green = rs_use_green(sta);
  	u8 active_tbl = 0;
  	u8 valid_tx_ant;
  	struct iwl_station_priv *sta_priv;
  	struct iwl_rxon_context *ctx;
  
  	if (!sta || !lq_sta)
  		return;
  
  	sta_priv = (void *)sta->drv_priv;
  	ctx = sta_priv->ctx;
  
  	i = lq_sta->last_txrate_idx;
  
  	valid_tx_ant = hw_params(priv).valid_tx_ant;
  
  	if (!lq_sta->search_better_tbl)
  		active_tbl = lq_sta->active_tbl;
  	else
  		active_tbl = 1 - lq_sta->active_tbl;
  
  	tbl = &(lq_sta->lq_info[active_tbl]);
  
  	if ((i < 0) || (i >= IWL_RATE_COUNT))
  		i = 0;
  
  	rate = iwl_rates[i].plcp;
  	tbl->ant_type = first_antenna(valid_tx_ant);
  	rate |= tbl->ant_type << RATE_MCS_ANT_POS;
  
  	if (i >= IWL_FIRST_CCK_RATE && i <= IWL_LAST_CCK_RATE)
  		rate |= RATE_MCS_CCK_MSK;
  
  	rs_get_tbl_info_from_mcs(rate, priv->band, tbl, &rate_idx);
  	if (!rs_is_valid_ant(valid_tx_ant, tbl->ant_type))
  	    rs_toggle_antenna(valid_tx_ant, &rate, tbl);
  
  	rate = rate_n_flags_from_tbl(priv, tbl, rate_idx, use_green);
  	tbl->current_rate = rate;
  	rs_set_expected_tpt_table(lq_sta, tbl);
  	rs_fill_link_cmd(NULL, lq_sta, rate);
  	priv->stations[lq_sta->lq.sta_id].lq = &lq_sta->lq;
  	iwl_send_lq_cmd(priv, ctx, &lq_sta->lq, CMD_SYNC, true);
  }
  
  static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta, void *priv_sta,
  			struct ieee80211_tx_rate_control *txrc)
  {
  
  	struct sk_buff *skb = txrc->skb;
  	struct ieee80211_supported_band *sband = txrc->sband;
  	struct iwl_priv *priv __maybe_unused = (struct iwl_priv *)priv_r;
  	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  	struct iwl_lq_sta *lq_sta = priv_sta;
  	int rate_idx;
  
  	IWL_DEBUG_RATE_LIMIT(priv, "rate scale calculate new rate for skb\n");
  
  	/* Get max rate if user set max rate */
  	if (lq_sta) {
  		lq_sta->max_rate_idx = txrc->max_rate_idx;
  		if ((sband->band == IEEE80211_BAND_5GHZ) &&
  		    (lq_sta->max_rate_idx != -1))
  			lq_sta->max_rate_idx += IWL_FIRST_OFDM_RATE;
  		if ((lq_sta->max_rate_idx < 0) ||
  		    (lq_sta->max_rate_idx >= IWL_RATE_COUNT))
  			lq_sta->max_rate_idx = -1;
  	}
  
  	/* Treat uninitialized rate scaling data same as non-existing. */
  	if (lq_sta && !lq_sta->drv) {
  		IWL_DEBUG_RATE(priv, "Rate scaling not initialized yet.\n");
  		priv_sta = NULL;
  	}
  
  	/* Send management frames and NO_ACK data using lowest rate. */
  	if (rate_control_send_low(sta, priv_sta, txrc))
  		return;
  
  	rate_idx  = lq_sta->last_txrate_idx;
  
  	if (lq_sta->last_rate_n_flags & RATE_MCS_HT_MSK) {
  		rate_idx -= IWL_FIRST_OFDM_RATE;
  		/* 6M and 9M shared same MCS index */
  		rate_idx = (rate_idx > 0) ? (rate_idx - 1) : 0;
  		if (rs_extract_rate(lq_sta->last_rate_n_flags) >=
  		    IWL_RATE_MIMO3_6M_PLCP)
  			rate_idx = rate_idx + (2 * MCS_INDEX_PER_STREAM);
  		else if (rs_extract_rate(lq_sta->last_rate_n_flags) >=
  			 IWL_RATE_MIMO2_6M_PLCP)
  			rate_idx = rate_idx + MCS_INDEX_PER_STREAM;
  		info->control.rates[0].flags = IEEE80211_TX_RC_MCS;
  		if (lq_sta->last_rate_n_flags & RATE_MCS_SGI_MSK)
  			info->control.rates[0].flags |= IEEE80211_TX_RC_SHORT_GI;
  		if (lq_sta->last_rate_n_flags & RATE_MCS_DUP_MSK)
  			info->control.rates[0].flags |= IEEE80211_TX_RC_DUP_DATA;
  		if (lq_sta->last_rate_n_flags & RATE_MCS_HT40_MSK)
  			info->control.rates[0].flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
  		if (lq_sta->last_rate_n_flags & RATE_MCS_GF_MSK)
  			info->control.rates[0].flags |= IEEE80211_TX_RC_GREEN_FIELD;
  	} else {
  		/* Check for invalid rates */
  		if ((rate_idx < 0) || (rate_idx >= IWL_RATE_COUNT_LEGACY) ||
  				((sband->band == IEEE80211_BAND_5GHZ) &&
  				 (rate_idx < IWL_FIRST_OFDM_RATE)))
  			rate_idx = rate_lowest_index(sband, sta);
  		/* On valid 5 GHz rate, adjust index */
  		else if (sband->band == IEEE80211_BAND_5GHZ)
  			rate_idx -= IWL_FIRST_OFDM_RATE;
  		info->control.rates[0].flags = 0;
  	}
  	info->control.rates[0].idx = rate_idx;
  
  }
  
  static void *rs_alloc_sta(void *priv_rate, struct ieee80211_sta *sta,
  			  gfp_t gfp)
  {
  	struct iwl_station_priv *sta_priv = (struct iwl_station_priv *) sta->drv_priv;
  	struct iwl_priv *priv;
  
  	priv = (struct iwl_priv *)priv_rate;
  	IWL_DEBUG_RATE(priv, "create station rate scale window\n");
  
  	return &sta_priv->lq_sta;
  }
  
  /*
   * Called after adding a new station to initialize rate scaling
   */
  void iwl_rs_rate_init(struct iwl_priv *priv, struct ieee80211_sta *sta, u8 sta_id)
  {
  	int i, j;
  	struct ieee80211_hw *hw = priv->hw;
  	struct ieee80211_conf *conf = &priv->hw->conf;
  	struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
  	struct iwl_station_priv *sta_priv;
  	struct iwl_lq_sta *lq_sta;
  	struct ieee80211_supported_band *sband;
  
  	sta_priv = (struct iwl_station_priv *) sta->drv_priv;
  	lq_sta = &sta_priv->lq_sta;
  	sband = hw->wiphy->bands[conf->channel->band];
  
  
  	lq_sta->lq.sta_id = sta_id;
  
  	for (j = 0; j < LQ_SIZE; j++)
  		for (i = 0; i < IWL_RATE_COUNT; i++)
  			rs_rate_scale_clear_window(&lq_sta->lq_info[j].win[i]);
  
  	lq_sta->flush_timer = 0;
  	lq_sta->supp_rates = sta->supp_rates[sband->band];
  	for (j = 0; j < LQ_SIZE; j++)
  		for (i = 0; i < IWL_RATE_COUNT; i++)
  			rs_rate_scale_clear_window(&lq_sta->lq_info[j].win[i]);
  
  	IWL_DEBUG_RATE(priv, "LQ: *** rate scale station global init for station %d ***\n",
  		       sta_id);
  	/* 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.. */
  
  	lq_sta->is_dup = 0;
  	lq_sta->max_rate_idx = -1;
  	lq_sta->missed_rate_counter = IWL_MISSED_RATE_MAX;
  	lq_sta->is_green = rs_use_green(sta);
  	lq_sta->active_legacy_rate = priv->active_rate & ~(0x1000);
  	lq_sta->band = priv->band;
  	/*
  	 * active_siso_rate mask includes 9 MBits (bit 5), and CCK (bits 0-3),
  	 * supp_rates[] does not; shift to convert format, force 9 MBits off.
  	 */
  	lq_sta->active_siso_rate = ht_cap->mcs.rx_mask[0] << 1;
  	lq_sta->active_siso_rate |= ht_cap->mcs.rx_mask[0] & 0x1;
  	lq_sta->active_siso_rate &= ~((u16)0x2);
  	lq_sta->active_siso_rate <<= IWL_FIRST_OFDM_RATE;
  
  	/* Same here */
  	lq_sta->active_mimo2_rate = ht_cap->mcs.rx_mask[1] << 1;
  	lq_sta->active_mimo2_rate |= ht_cap->mcs.rx_mask[1] & 0x1;
  	lq_sta->active_mimo2_rate &= ~((u16)0x2);
  	lq_sta->active_mimo2_rate <<= IWL_FIRST_OFDM_RATE;
  
  	lq_sta->active_mimo3_rate = ht_cap->mcs.rx_mask[2] << 1;
  	lq_sta->active_mimo3_rate |= ht_cap->mcs.rx_mask[2] & 0x1;
  	lq_sta->active_mimo3_rate &= ~((u16)0x2);
  	lq_sta->active_mimo3_rate <<= IWL_FIRST_OFDM_RATE;
  
  	IWL_DEBUG_RATE(priv, "SISO-RATE=%X MIMO2-RATE=%X MIMO3-RATE=%X\n",
  		     lq_sta->active_siso_rate,
  		     lq_sta->active_mimo2_rate,
  		     lq_sta->active_mimo3_rate);
  
  	/* These values will be overridden later */
  	lq_sta->lq.general_params.single_stream_ant_msk =
  		first_antenna(hw_params(priv).valid_tx_ant);
  	lq_sta->lq.general_params.dual_stream_ant_msk =
  		hw_params(priv).valid_tx_ant &
  		~first_antenna(hw_params(priv).valid_tx_ant);
  	if (!lq_sta->lq.general_params.dual_stream_ant_msk) {
  		lq_sta->lq.general_params.dual_stream_ant_msk = ANT_AB;
  	} else if (num_of_ant(hw_params(priv).valid_tx_ant) == 2) {
  		lq_sta->lq.general_params.dual_stream_ant_msk =
  			hw_params(priv).valid_tx_ant;
  	}
  
  	/* as default allow aggregation for all tids */
  	lq_sta->tx_agg_tid_en = IWL_AGG_ALL_TID;
  	lq_sta->drv = priv;
  
  	/* Set last_txrate_idx to lowest rate */
  	lq_sta->last_txrate_idx = rate_lowest_index(sband, sta);
  	if (sband->band == IEEE80211_BAND_5GHZ)
  		lq_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
  	lq_sta->is_agg = 0;
  #ifdef CONFIG_IWLWIFI_DEVICE_SVTOOL
  	priv->tm_fixed_rate = 0;
  #endif
  #ifdef CONFIG_MAC80211_DEBUGFS
  	lq_sta->dbg_fixed_rate = 0;
  #endif
  
  	rs_initialize_lq(priv, conf, sta, lq_sta);
  }
  
  static void rs_fill_link_cmd(struct iwl_priv *priv,
  			     struct iwl_lq_sta *lq_sta, u32 new_rate)
  {
  	struct iwl_scale_tbl_info tbl_type;
  	int index = 0;
  	int rate_idx;
  	int repeat_rate = 0;
  	u8 ant_toggle_cnt = 0;
  	u8 use_ht_possible = 1;
  	u8 valid_tx_ant = 0;
  	struct iwl_station_priv *sta_priv =
  		container_of(lq_sta, struct iwl_station_priv, lq_sta);
  	struct iwl_link_quality_cmd *lq_cmd = &lq_sta->lq;
  
  	/* Override starting rate (index 0) if needed for debug purposes */
  	rs_dbgfs_set_mcs(lq_sta, &new_rate, index);
  
  	/* Interpret new_rate (rate_n_flags) */
  	rs_get_tbl_info_from_mcs(new_rate, lq_sta->band,
  				  &tbl_type, &rate_idx);
  
  	if (priv && priv->bt_full_concurrent) {
  		/* 1x1 only */
  		tbl_type.ant_type =
  			first_antenna(hw_params(priv).valid_tx_ant);
  	}
  
  	/* How many times should we repeat the initial rate? */
  	if (is_legacy(tbl_type.lq_type)) {
  		ant_toggle_cnt = 1;
  		repeat_rate = IWL_NUMBER_TRY;
  	} else {
  		repeat_rate = min(IWL_HT_NUMBER_TRY,
  				  LINK_QUAL_AGG_DISABLE_START_DEF - 1);
  	}
  
  	lq_cmd->general_params.mimo_delimiter =
  			is_mimo(tbl_type.lq_type) ? 1 : 0;
  
  	/* Fill 1st table entry (index 0) */
  	lq_cmd->rs_table[index].rate_n_flags = cpu_to_le32(new_rate);
  
  	if (num_of_ant(tbl_type.ant_type) == 1) {
  		lq_cmd->general_params.single_stream_ant_msk =
  						tbl_type.ant_type;
  	} else if (num_of_ant(tbl_type.ant_type) == 2) {
  		lq_cmd->general_params.dual_stream_ant_msk =
  						tbl_type.ant_type;
  	} /* otherwise we don't modify the existing value */
  
  	index++;
  	repeat_rate--;
  	if (priv) {
  		if (priv->bt_full_concurrent)
  			valid_tx_ant = ANT_A;
  		else
  			valid_tx_ant = hw_params(priv).valid_tx_ant;
  	}
  
  	/* Fill rest of rate table */
  	while (index < LINK_QUAL_MAX_RETRY_NUM) {
  		/* Repeat initial/next rate.
  		 * For legacy IWL_NUMBER_TRY == 1, this loop will not execute.
  		 * For HT IWL_HT_NUMBER_TRY == 3, this executes twice. */
  		while (repeat_rate > 0 && (index < LINK_QUAL_MAX_RETRY_NUM)) {
  			if (is_legacy(tbl_type.lq_type)) {
  				if (ant_toggle_cnt < NUM_TRY_BEFORE_ANT_TOGGLE)
  					ant_toggle_cnt++;
  				else if (priv &&
  					 rs_toggle_antenna(valid_tx_ant,
  							&new_rate, &tbl_type))
  					ant_toggle_cnt = 1;
  			}
  
  			/* Override next rate if needed for debug purposes */
  			rs_dbgfs_set_mcs(lq_sta, &new_rate, index);
  
  			/* Fill next table entry */
  			lq_cmd->rs_table[index].rate_n_flags =
  					cpu_to_le32(new_rate);
  			repeat_rate--;
  			index++;
  		}
  
  		rs_get_tbl_info_from_mcs(new_rate, lq_sta->band, &tbl_type,
  						&rate_idx);
  
  		if (priv && priv->bt_full_concurrent) {
  			/* 1x1 only */
  			tbl_type.ant_type =
  			    first_antenna(hw_params(priv).valid_tx_ant);
  		}
  
  		/* Indicate to uCode which entries might be MIMO.
  		 * If initial rate was MIMO, this will finally end up
  		 * as (IWL_HT_NUMBER_TRY * 2), after 2nd pass, otherwise 0. */
  		if (is_mimo(tbl_type.lq_type))
  			lq_cmd->general_params.mimo_delimiter = index;
  
  		/* Get next rate */
  		new_rate = rs_get_lower_rate(lq_sta, &tbl_type, rate_idx,
  					     use_ht_possible);
  
  		/* How many times should we repeat the next rate? */
  		if (is_legacy(tbl_type.lq_type)) {
  			if (ant_toggle_cnt < NUM_TRY_BEFORE_ANT_TOGGLE)
  				ant_toggle_cnt++;
  			else if (priv &&
  				 rs_toggle_antenna(valid_tx_ant,
  						   &new_rate, &tbl_type))
  				ant_toggle_cnt = 1;
  
  			repeat_rate = IWL_NUMBER_TRY;
  		} else {
  			repeat_rate = IWL_HT_NUMBER_TRY;
  		}
  
  		/* Don't allow HT rates after next pass.
  		 * rs_get_lower_rate() will change type to LQ_A or LQ_G. */
  		use_ht_possible = 0;
  
  		/* Override next rate if needed for debug purposes */
  		rs_dbgfs_set_mcs(lq_sta, &new_rate, index);
  
  		/* Fill next table entry */
  		lq_cmd->rs_table[index].rate_n_flags = cpu_to_le32(new_rate);
  
  		index++;
  		repeat_rate--;
  	}
  
  	lq_cmd->agg_params.agg_frame_cnt_limit =
  		sta_priv->max_agg_bufsize ?: LINK_QUAL_AGG_FRAME_LIMIT_DEF;
  	lq_cmd->agg_params.agg_dis_start_th = LINK_QUAL_AGG_DISABLE_START_DEF;
  
  	lq_cmd->agg_params.agg_time_limit =
  		cpu_to_le16(LINK_QUAL_AGG_TIME_LIMIT_DEF);
  	/*
  	 * overwrite if needed, pass aggregation time limit
  	 * to uCode in uSec
  	 */
  	if (priv && priv->cfg->bt_params &&
  	    priv->cfg->bt_params->agg_time_limit &&
  	    priv->bt_traffic_load >= IWL_BT_COEX_TRAFFIC_LOAD_HIGH)
  		lq_cmd->agg_params.agg_time_limit =
  			cpu_to_le16(priv->cfg->bt_params->agg_time_limit);
  }
  
  static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
  {
  	return hw->priv;
  }
  /* rate scale requires free function to be implemented */
  static void rs_free(void *priv_rate)
  {
  	return;
  }
  
  static void rs_free_sta(void *priv_r, struct ieee80211_sta *sta,
  			void *priv_sta)
  {
  	struct iwl_priv *priv __maybe_unused = priv_r;
  
  	IWL_DEBUG_RATE(priv, "enter\n");
  	IWL_DEBUG_RATE(priv, "leave\n");
  }
  
  #ifdef CONFIG_MAC80211_DEBUGFS
  static int open_file_generic(struct inode *inode, struct file *file)
  {
  	file->private_data = inode->i_private;
  	return 0;
  }
  static void rs_dbgfs_set_mcs(struct iwl_lq_sta *lq_sta,
  			     u32 *rate_n_flags, int index)
  {
  	struct iwl_priv *priv;
  	u8 valid_tx_ant;
  	u8 ant_sel_tx;
  
  	priv = lq_sta->drv;
  	valid_tx_ant = hw_params(priv).valid_tx_ant;
  	if (lq_sta->dbg_fixed_rate) {
  		ant_sel_tx =
  		  ((lq_sta->dbg_fixed_rate & RATE_MCS_ANT_ABC_MSK)
  		  >> RATE_MCS_ANT_POS);
  		if ((valid_tx_ant & ant_sel_tx) == ant_sel_tx) {
  			*rate_n_flags = lq_sta->dbg_fixed_rate;
  			IWL_DEBUG_RATE(priv, "Fixed rate ON\n");
  		} else {
  			lq_sta->dbg_fixed_rate = 0;
  			IWL_ERR(priv,
  			    "Invalid antenna selection 0x%X, Valid is 0x%X\n",
  			    ant_sel_tx, valid_tx_ant);
  			IWL_DEBUG_RATE(priv, "Fixed rate OFF\n");
  		}
  	} else {
  		IWL_DEBUG_RATE(priv, "Fixed rate OFF\n");
  	}
  }
  
  static ssize_t rs_sta_dbgfs_scale_table_write(struct file *file,
  			const char __user *user_buf, size_t count, loff_t *ppos)
  {
  	struct iwl_lq_sta *lq_sta = file->private_data;
  	struct iwl_priv *priv;
  	char buf[64];
  	size_t buf_size;
  	u32 parsed_rate;
  
  
  	priv = lq_sta->drv;
  	memset(buf, 0, sizeof(buf));
  	buf_size = min(count, sizeof(buf) -  1);
  	if (copy_from_user(buf, user_buf, buf_size))
  		return -EFAULT;
  
  	if (sscanf(buf, "%x", &parsed_rate) == 1)
  		lq_sta->dbg_fixed_rate = parsed_rate;
  	else
  		lq_sta->dbg_fixed_rate = 0;
  
  	rs_program_fix_rate(priv, lq_sta);
  
  	return count;
  }
  
  static ssize_t rs_sta_dbgfs_scale_table_read(struct file *file,
  			char __user *user_buf, size_t count, loff_t *ppos)
  {
  	char *buff;
  	int desc = 0;
  	int i = 0;
  	int index = 0;
  	ssize_t ret;
  
  	struct iwl_lq_sta *lq_sta = file->private_data;
  	struct iwl_priv *priv;
  	struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
  
  	priv = lq_sta->drv;
  	buff = kmalloc(1024, GFP_KERNEL);
  	if (!buff)
  		return -ENOMEM;
  
  	desc += sprintf(buff+desc, "sta_id %d\n", lq_sta->lq.sta_id);
  	desc += sprintf(buff+desc, "failed=%d success=%d rate=0%X\n",
  			lq_sta->total_failed, lq_sta->total_success,
  			lq_sta->active_legacy_rate);
  	desc += sprintf(buff+desc, "fixed rate 0x%X\n",
  			lq_sta->dbg_fixed_rate);
  	desc += sprintf(buff+desc, "valid_tx_ant %s%s%s\n",
  	    (hw_params(priv).valid_tx_ant & ANT_A) ? "ANT_A," : "",
  	    (hw_params(priv).valid_tx_ant & ANT_B) ? "ANT_B," : "",
  	    (hw_params(priv).valid_tx_ant & ANT_C) ? "ANT_C" : "");
  	desc += sprintf(buff+desc, "lq type %s\n",
  	   (is_legacy(tbl->lq_type)) ? "legacy" : "HT");
  	if (is_Ht(tbl->lq_type)) {
  		desc += sprintf(buff+desc, " %s",
  		   (is_siso(tbl->lq_type)) ? "SISO" :
  		   ((is_mimo2(tbl->lq_type)) ? "MIMO2" : "MIMO3"));
  		   desc += sprintf(buff+desc, " %s",
  		   (tbl->is_ht40) ? "40MHz" : "20MHz");
  		   desc += sprintf(buff+desc, " %s %s %s\n", (tbl->is_SGI) ? "SGI" : "",
  		   (lq_sta->is_green) ? "GF enabled" : "",
  		   (lq_sta->is_agg) ? "AGG on" : "");
  	}
  	desc += sprintf(buff+desc, "last tx rate=0x%X\n",
  		lq_sta->last_rate_n_flags);
  	desc += sprintf(buff+desc, "general:"
  		"flags=0x%X mimo-d=%d s-ant0x%x d-ant=0x%x\n",
  		lq_sta->lq.general_params.flags,
  		lq_sta->lq.general_params.mimo_delimiter,
  		lq_sta->lq.general_params.single_stream_ant_msk,
  		lq_sta->lq.general_params.dual_stream_ant_msk);
  
  	desc += sprintf(buff+desc, "agg:"
  			"time_limit=%d dist_start_th=%d frame_cnt_limit=%d\n",
  			le16_to_cpu(lq_sta->lq.agg_params.agg_time_limit),
  			lq_sta->lq.agg_params.agg_dis_start_th,
  			lq_sta->lq.agg_params.agg_frame_cnt_limit);
  
  	desc += sprintf(buff+desc,
  			"Start idx [0]=0x%x [1]=0x%x [2]=0x%x [3]=0x%x\n",
  			lq_sta->lq.general_params.start_rate_index[0],
  			lq_sta->lq.general_params.start_rate_index[1],
  			lq_sta->lq.general_params.start_rate_index[2],
  			lq_sta->lq.general_params.start_rate_index[3]);
  
  	for (i = 0; i < LINK_QUAL_MAX_RETRY_NUM; i++) {
  		index = iwl_hwrate_to_plcp_idx(
  			le32_to_cpu(lq_sta->lq.rs_table[i].rate_n_flags));
  		if (is_legacy(tbl->lq_type)) {
  			desc += sprintf(buff+desc, " rate[%d] 0x%X %smbps\n",
  				i, le32_to_cpu(lq_sta->lq.rs_table[i].rate_n_flags),
  				iwl_rate_mcs[index].mbps);
  		} else {
  			desc += sprintf(buff+desc, " rate[%d] 0x%X %smbps (%s)\n",
  				i, le32_to_cpu(lq_sta->lq.rs_table[i].rate_n_flags),
  				iwl_rate_mcs[index].mbps, iwl_rate_mcs[index].mcs);
  		}
  	}
  
  	ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
  	kfree(buff);
  	return ret;
  }
  
  static const struct file_operations rs_sta_dbgfs_scale_table_ops = {
  	.write = rs_sta_dbgfs_scale_table_write,
  	.read = rs_sta_dbgfs_scale_table_read,
  	.open = open_file_generic,
  	.llseek = default_llseek,
  };
  static ssize_t rs_sta_dbgfs_stats_table_read(struct file *file,
  			char __user *user_buf, size_t count, loff_t *ppos)
  {
  	char *buff;
  	int desc = 0;
  	int i, j;
  	ssize_t ret;
  
  	struct iwl_lq_sta *lq_sta = file->private_data;
  
  	buff = kmalloc(1024, GFP_KERNEL);
  	if (!buff)
  		return -ENOMEM;
  
  	for (i = 0; i < LQ_SIZE; i++) {
  		desc += sprintf(buff+desc,
  				"%s type=%d SGI=%d HT40=%d DUP=%d GF=%d\n"
  				"rate=0x%X\n",
  				lq_sta->active_tbl == i ? "*" : "x",
  				lq_sta->lq_info[i].lq_type,
  				lq_sta->lq_info[i].is_SGI,
  				lq_sta->lq_info[i].is_ht40,
  				lq_sta->lq_info[i].is_dup,
  				lq_sta->is_green,
  				lq_sta->lq_info[i].current_rate);
  		for (j = 0; j < IWL_RATE_COUNT; j++) {
  			desc += sprintf(buff+desc,
  				"counter=%d success=%d %%=%d\n",
  				lq_sta->lq_info[i].win[j].counter,
  				lq_sta->lq_info[i].win[j].success_counter,
  				lq_sta->lq_info[i].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 = rs_sta_dbgfs_stats_table_read,
  	.open = open_file_generic,
  	.llseek = default_llseek,
  };
  
  static ssize_t rs_sta_dbgfs_rate_scale_data_read(struct file *file,
  			char __user *user_buf, size_t count, loff_t *ppos)
  {
  	struct iwl_lq_sta *lq_sta = file->private_data;
  	struct iwl_scale_tbl_info *tbl = &lq_sta->lq_info[lq_sta->active_tbl];
  	char buff[120];
  	int desc = 0;
  
  	if (is_Ht(tbl->lq_type))
  		desc += sprintf(buff+desc,
  				"Bit Rate= %d Mb/s\n",
  				tbl->expected_tpt[lq_sta->last_txrate_idx]);
  	else
  		desc += sprintf(buff+desc,
  				"Bit Rate= %d Mb/s\n",
  				iwl_rates[lq_sta->last_txrate_idx].ieee >> 1);
  
  	return simple_read_from_buffer(user_buf, count, ppos, buff, desc);
  }
  
  static const struct file_operations rs_sta_dbgfs_rate_scale_data_ops = {
  	.read = rs_sta_dbgfs_rate_scale_data_read,
  	.open = open_file_generic,
  	.llseek = default_llseek,
  };
  
  static void rs_add_debugfs(void *priv, void *priv_sta,
  					struct dentry *dir)
  {
  	struct iwl_lq_sta *lq_sta = priv_sta;
  	lq_sta->rs_sta_dbgfs_scale_table_file =
  		debugfs_create_file("rate_scale_table", S_IRUSR | S_IWUSR, dir,
  				lq_sta, &rs_sta_dbgfs_scale_table_ops);
  	lq_sta->rs_sta_dbgfs_stats_table_file =
  		debugfs_create_file("rate_stats_table", S_IRUSR, dir,
  			lq_sta, &rs_sta_dbgfs_stats_table_ops);
  	lq_sta->rs_sta_dbgfs_rate_scale_data_file =
  		debugfs_create_file("rate_scale_data", S_IRUSR, dir,
  			lq_sta, &rs_sta_dbgfs_rate_scale_data_ops);
  	lq_sta->rs_sta_dbgfs_tx_agg_tid_en_file =
  		debugfs_create_u8("tx_agg_tid_enable", S_IRUSR | S_IWUSR, dir,
  		&lq_sta->tx_agg_tid_en);
  
  }
  
  static void rs_remove_debugfs(void *priv, void *priv_sta)
  {
  	struct iwl_lq_sta *lq_sta = priv_sta;
  	debugfs_remove(lq_sta->rs_sta_dbgfs_scale_table_file);
  	debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
  	debugfs_remove(lq_sta->rs_sta_dbgfs_rate_scale_data_file);
  	debugfs_remove(lq_sta->rs_sta_dbgfs_tx_agg_tid_en_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 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 = rs_tx_status,
  	.get_rate = rs_get_rate,
  	.rate_init = rs_rate_init_stub,
  	.alloc = rs_alloc,
  	.free = rs_free,
  	.alloc_sta = rs_alloc_sta,
  	.free_sta = rs_free_sta,
  #ifdef CONFIG_MAC80211_DEBUGFS
  	.add_sta_debugfs = rs_add_debugfs,
  	.remove_sta_debugfs = rs_remove_debugfs,
  #endif
  };
  
  int iwlagn_rate_control_register(void)
  {
  	return ieee80211_rate_control_register(&rs_ops);
  }
  
  void iwlagn_rate_control_unregister(void)
  {
  	ieee80211_rate_control_unregister(&rs_ops);
  }
  
  