iwlwifi: split the drivers for agn and legacy devices 3945/4965

Intel WiFi devices 3945 and 4965 now have their own driver in the folder

	drivers/net/wireless/iwlegacy

Add support to build these drivers independently of the driver for
AGN devices. Selecting the 3945 builds iwl3945.ko and iwl_legacy.ko,
and selecting the 4965 builds iwl4965.ko and iwl_legacy.ko. iwl-legacy.ko
contains code shared between both devices.

The 3945 is an ABG/BG device, with no support for 802.11n. The 4965 is a 2x3
ABGN device.

Signed-off-by: Meenakshi Venkataraman <meenakshi.venkataraman@intel.com>
Acked-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>

1 files changed, 2870 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlegacy/iwl-4965-rs.c b/drivers/net/wireless/iwlegacy/iwl-4965-rs.c
new file mode 100644
index 000000000000..69abd2816f8d
--- /dev/null
+++ b/drivers/net/wireless/iwlegacy/iwl-4965-rs.c
@@ -0,0 +1,2870 @@
+/******************************************************************************
+ *
+ * Copyright(c) 2005 - 2011 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
+ *
+ * The full GNU General Public License is included in this distribution in the
+ * file called LICENSE.
+ *
+ * Contact Information:
+ *  Intel Linux Wireless <ilw@linux.intel.com>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *
+ *****************************************************************************/
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/wireless.h>
+#include <net/mac80211.h>
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/delay.h>
+
+#include <linux/workqueue.h>
+
+#include "iwl-dev.h"
+#include "iwl-sta.h"
+#include "iwl-core.h"
+#include "iwl-4965.h"
+
+#define IWL4965_RS_NAME "iwl-4965-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_##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 */
+};
+
+static int iwl4965_hwrate_to_plcp_idx(u32 rate_n_flags)
+{
+	int idx = 0;
+
+	/* HT rate format */
+	if (rate_n_flags & RATE_MCS_HT_MSK) {
+		idx = (rate_n_flags & 0xff);
+
+		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 == (rate_n_flags & 0xFF))
+				return idx;
+	}
+
+	return -1;
+}
+
+static void iwl4965_rs_rate_scale_perform(struct iwl_priv *priv,
+				   struct sk_buff *skb,
+				   struct ieee80211_sta *sta,
+				   struct iwl_lq_sta *lq_sta);
+static void iwl4965_rs_fill_link_cmd(struct iwl_priv *priv,
+			     struct iwl_lq_sta *lq_sta, u32 rate_n_flags);
+static void iwl4965_rs_stay_in_table(struct iwl_lq_sta *lq_sta,
+					bool force_search);
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+static void iwl4965_rs_dbgfs_set_mcs(struct iwl_lq_sta *lq_sta,
+			     u32 *rate_n_flags, int index);
+#else
+static void iwl4965_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, 158, 183, 193, 202}, /* Norm */
+	{0, 0, 0, 0, 46, 0,  82, 110, 132, 167, 192, 202, 210}, /* SGI */
+	{0, 0, 0, 0, 48, 0,  93, 135, 176, 251, 319, 351, 381}, /* AGG */
+	{0, 0, 0, 0, 53, 0, 102, 149, 193, 275, 348, 381, 413}, /* 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,  96, 0, 182, 259, 328, 451, 553, 598, 640}, /* AGG */
+	{0, 0, 0, 0, 106, 0, 199, 282, 357, 487, 593, 640, 683}, /* AGG+SGI */
+};
+
+static s32 expected_tpt_mimo2_20MHz[4][IWL_RATE_COUNT] = {
+	{0, 0, 0, 0,  74, 0, 123, 155, 179, 213, 235, 243, 250}, /* Norm */
+	{0, 0, 0, 0,  81, 0, 131, 164, 187, 221, 242, 250, 256}, /* SGI */
+	{0, 0, 0, 0,  92, 0, 175, 250, 317, 436, 534, 578, 619}, /* AGG */
+	{0, 0, 0, 0, 102, 0, 192, 273, 344, 470, 573, 619, 660}, /* 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, 180, 0, 327, 446, 545, 708, 828, 878, 922}, /* AGG */
+	{0, 0, 0, 0, 197, 0, 355, 481, 584, 752, 872, 922, 966}, /* 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 inline u8 iwl4965_rs_extract_rate(u32 rate_n_flags)
+{
+	return (u8)(rate_n_flags & 0xFF);
+}
+
+static void
+iwl4965_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 iwl4965_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
+iwl4965_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 iwl4965_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 MAX_TID_COUNT;
+
+	if (unlikely(tid >= TID_MAX_LOAD_COUNT))
+		return 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 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)
+		iwl4965_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;
+}
+
+/*
+	get the traffic load value for tid
+*/
+static u32 iwl4965_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)
+		iwl4965_rs_tl_rm_old_stats(tl, curr_time);
+
+	return tl->total;
+}
+
+static int iwl4965_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;
+
+	load = iwl4965_rs_tl_get_load(lq_data, tid);
+
+	if (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_ERR(priv, "Aggregation not enabled for tid %d "
+			"because load = %u\n", tid, load);
+	}
+	return ret;
+}
+
+static void iwl4965_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)
+		iwl4965_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 iwl4965_get_iwl4965_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
+iwl4965_get_expected_tpt(struct iwl_scale_tbl_info *tbl, int rs_index)
+{
+	if (tbl->expected_tpt)
+		return tbl->expected_tpt[rs_index];
+	return 0;
+}
+
+/**
+ * iwl4965_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 iwl4965_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 = iwl4965_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.
+ */
+static u32 iwl4965_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
+			rate_n_flags |=	iwl_rates[index].plcp_mimo2;
+	} 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 iwl4965_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 iwl4965_num_of_ant = iwl4965_get_iwl4965_num_of_ant_from_rate(rate_n_flags);
+	u8 mcs;
+
+	memset(tbl, 0, sizeof(struct iwl_scale_tbl_info));
+	*rate_idx = iwl4965_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 (iwl4965_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 = iwl4965_rs_extract_rate(rate_n_flags);
+
+		/* SISO */
+		if (mcs <= IWL_RATE_SISO_60M_PLCP) {
+			if (iwl4965_num_of_ant == 1)
+				tbl->lq_type = LQ_SISO; /*else NONE*/
+		/* MIMO2 */
+		} else {
+			if (iwl4965_num_of_ant == 2)
+				tbl->lq_type = LQ_MIMO2;
+		}
+	}
+	return 0;
+}
+
+/* switch to another antenna/antennas and return 1 */
+/* if no other valid antenna found, return 0 */
+static int iwl4965_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 (!iwl4965_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) &&
+	       !iwl4965_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 iwl4965_rs_use_green(struct ieee80211_sta *sta)
+{
+	struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
+	struct iwl_rxon_context *ctx = sta_priv->common.ctx;
+
+	return (sta->ht_cap.cap & IEEE80211_HT_CAP_GRN_FLD) &&
+		!(ctx->ht.non_gf_sta_present);
+}
+
+/**
+ * iwl4965_rs_get_supported_rates - get the available rates
+ *
+ * if management frame or broadcast frame only return
+ * basic available rates.
+ *
+ */
+static u16 iwl4965_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
+			return lq_sta->active_mimo2_rate;
+	}
+}
+
+static u16
+iwl4965_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 iwl4965_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 (iwl4965_num_of_ant(tbl->ant_type) > 1)
+			tbl->ant_type =
+				iwl4965_first_antenna(priv->hw_params.valid_tx_ant);
+
+		tbl->is_ht40 = 0;
+		tbl->is_SGI = 0;
+		tbl->max_search = IWL_MAX_SEARCH;
+	}
+
+	rate_mask = iwl4965_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 = iwl4965_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 iwl4965_rate_n_flags_from_tbl(lq_sta->drv, tbl, low, is_green);
+}
+
+/*
+ * Simple function to compare two rate scale table types
+ */
+static bool iwl4965_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);
+}
+
+/*
+ * mac80211 sends us Tx status
+ */
+static void
+iwl4965_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->common.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);
+	iwl4965_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_legacy_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 (iwl4965_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 (iwl4965_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
+		 */
+		iwl4965_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);
+		iwl4965_rs_get_tbl_info_from_mcs(tx_rate, priv->band, &tbl_type,
+				&rs_index);
+		iwl4965_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);
+			iwl4965_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 (iwl4965_table_type_matches(&tbl_type, curr_tbl))
+				tmp_tbl = curr_tbl;
+			else if (iwl4965_table_type_matches(&tbl_type,
+								 other_tbl))
+				tmp_tbl = other_tbl;
+			else
+				continue;
+			iwl4965_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])
+		iwl4965_rs_rate_scale_perform(priv, skb, sta, 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 iwl4965_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 iwl4965_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), 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)) <-- must be true */
+		ht_tbl_pointer = expected_tpt_mimo2_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 iwl4965_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 = iwl4965_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 iwl4965_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->common.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 (priv->hw_params.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_legacy_is_ht40_tx_allowed(priv, ctx, &sta->ht_cap))
+		tbl->is_ht40 = 1;
+	else
+		tbl->is_ht40 = 0;
+
+	iwl4965_rs_set_expected_tpt_table(lq_sta, tbl);
+
+	rate = iwl4965_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 = iwl4965_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 iwl4965_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->common.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_legacy_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*/
+
+	iwl4965_rs_set_expected_tpt_table(lq_sta, tbl);
+	rate = iwl4965_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 = iwl4965_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 iwl4965_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 = priv->hw_params.valid_tx_ant;
+	u8 tx_chains_num = priv->hw_params.tx_chains_num;
+	int ret = 0;
+	u8 update_search_tbl_counter = 0;
+
+	tbl->action = IWL_LEGACY_SWITCH_SISO;
+
+	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)
+				break;
+
+			/* Set up search table to try other antenna */
+			memcpy(search_tbl, tbl, sz);
+
+			if (iwl4965_rs_toggle_antenna(valid_tx_ant,
+				&search_tbl->current_rate, search_tbl)) {
+				update_search_tbl_counter = 1;
+				iwl4965_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 = iwl4965_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 (!iwl4965_rs_is_valid_ant(valid_tx_ant,
+						search_tbl->ant_type))
+				break;
+
+			ret = iwl4965_rs_switch_to_mimo2(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_MIMO2_BC)
+			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_MIMO2_BC)
+		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 iwl4965_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 = priv->hw_params.valid_tx_ant;
+	u8 tx_chains_num = priv->hw_params.tx_chains_num;
+	u8 update_search_tbl_counter = 0;
+	int ret;
+
+	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)
+				break;
+
+			memcpy(search_tbl, tbl, sz);
+			if (iwl4965_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 (!iwl4965_rs_is_valid_ant(valid_tx_ant,
+						 search_tbl->ant_type))
+				break;
+
+			ret = iwl4965_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;
+			iwl4965_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 =
+				iwl4965_rate_n_flags_from_tbl(priv, search_tbl,
+						      index, is_green);
+			update_search_tbl_counter = 1;
+			goto out;
+		}
+		tbl->action++;
+		if (tbl->action > IWL_SISO_SWITCH_GI)
+			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_GI)
+		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 iwl4965_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 = priv->hw_params.valid_tx_ant;
+	u8 tx_chains_num = priv->hw_params.tx_chains_num;
+	u8 update_search_tbl_counter = 0;
+	int ret;
+
+	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 (iwl4965_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 (!iwl4965_rs_is_valid_ant(valid_tx_ant,
+						search_tbl->ant_type))
+				break;
+
+			ret = iwl4965_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;
+			iwl4965_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 =
+				iwl4965_rate_n_flags_from_tbl(priv, search_tbl,
+						      index, is_green);
+			update_search_tbl_counter = 1;
+			goto out;
+
+		}
+		tbl->action++;
+		if (tbl->action > IWL_MIMO2_SWITCH_GI)
+			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_GI)
+		tbl->action = IWL_MIMO2_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
+iwl4965_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++)
+					iwl4965_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++)
+				iwl4965_rs_rate_scale_clear_window(
+							&(tbl->win[i]));
+		}
+	}
+}
+
+/*
+ * setup rate table in uCode
+ * return rate_n_flags as used in the table
+ */
+static u32 iwl4965_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 = iwl4965_rate_n_flags_from_tbl(priv, tbl, index, is_green);
+	iwl4965_rs_fill_link_cmd(priv, lq_sta, rate);
+	iwl_legacy_send_lq_cmd(priv, ctx, &lq_sta->lq, CMD_ASYNC, false);
+
+	return rate;
+}
+
+/*
+ * Do rate scaling and search for new modulation mode.
+ */
+static void iwl4965_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;
+	u32 rate;
+	u8 is_green = 0;
+	u8 active_tbl = 0;
+	u8 done_search = 0;
+	u16 high_low;
+	s32 sr;
+	u8 tid = 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->common.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;
+
+	if (!sta || !lq_sta)
+		return;
+
+	lq_sta->supp_rates = sta->supp_rates[lq_sta->band];
+
+	tid = iwl4965_rs_tl_add_packet(lq_sta, hdr);
+	if ((tid != MAX_TID_COUNT) && (lq_sta->tx_agg_tid_en & (1 << tid))) {
+		tid_data = &priv->stations[lq_sta->lq.sta_id].tid[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 = iwl4965_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 = iwl4965_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 = iwl4965_hwrate_to_plcp_idx(tbl->current_rate);
+			rate = iwl4965_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? */
+		iwl4965_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) {
+		/* 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 = iwl4965_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 = iwl4965_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;
+
+	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)
+		rate = iwl4965_rs_update_rate_tbl(priv, ctx, lq_sta,
+					  tbl, index, is_green);
+
+	/* Should we stay with this modulation mode,
+	 * or search for a new one? */
+	 iwl4965_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))
+			iwl4965_rs_move_legacy_other(priv, lq_sta,
+							conf, sta, index);
+		else if (is_siso(tbl->lq_type))
+			iwl4965_rs_move_siso_to_other(priv, lq_sta,
+							conf, sta, index);
+		else /* (is_mimo2(tbl->lq_type)) */
+			iwl4965_rs_move_mimo2_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++)
+				iwl4965_rs_rate_scale_clear_window(
+							&(tbl->win[i]));
+
+			/* Use new "search" start rate */
+			index = iwl4965_hwrate_to_plcp_idx(tbl->current_rate);
+
+			IWL_DEBUG_RATE(priv,
+				"Switch current  mcs: %X index: %d\n",
+				     tbl->current_rate, index);
+			iwl4965_rs_fill_link_cmd(priv, lq_sta,
+						tbl->current_rate);
+			iwl_legacy_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");
+			iwl4965_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)) {
+			if ((lq_sta->last_tpt > IWL_AGG_TPT_THREHOLD) &&
+			    (lq_sta->tx_agg_tid_en & (1 << tid)) &&
+			    (tid != MAX_TID_COUNT)) {
+				tid_data =
+				   &priv->stations[lq_sta->lq.sta_id].tid[tid];
+				if (tid_data->agg.state == IWL_AGG_OFF) {
+					IWL_DEBUG_RATE(priv,
+						       "try to aggregate tid %d\n",
+						       tid);
+					iwl4965_rs_tl_turn_on_agg(priv, tid,
+							  lq_sta, sta);
+				}
+			}
+			iwl4965_rs_set_stay_in_table(priv, 0, lq_sta);
+		}
+	}
+
+out:
+	tbl->current_rate = iwl4965_rate_n_flags_from_tbl(priv, tbl,
+							index, is_green);
+	i = index;
+	lq_sta->last_txrate_idx = i;
+}
+
+/**
+ * iwl4965_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-4965-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 iwl4965_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 = iwl4965_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->common.ctx;
+
+	i = lq_sta->last_txrate_idx;
+
+	valid_tx_ant = priv->hw_params.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 = iwl4965_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;
+
+	iwl4965_rs_get_tbl_info_from_mcs(rate, priv->band, tbl, &rate_idx);
+	if (!iwl4965_rs_is_valid_ant(valid_tx_ant, tbl->ant_type))
+		iwl4965_rs_toggle_antenna(valid_tx_ant, &rate, tbl);
+
+	rate = iwl4965_rate_n_flags_from_tbl(priv, tbl, rate_idx, use_green);
+	tbl->current_rate = rate;
+	iwl4965_rs_set_expected_tpt_table(lq_sta, tbl);
+	iwl4965_rs_fill_link_cmd(NULL, lq_sta, rate);
+	priv->stations[lq_sta->lq.sta_id].lq = &lq_sta->lq;
+	iwl_legacy_send_lq_cmd(priv, ctx, &lq_sta->lq, CMD_SYNC, true);
+}
+
+static void
+iwl4965_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 (iwl4965_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 *iwl4965_rs_alloc_sta(void *priv_rate, struct ieee80211_sta *sta,
+			  gfp_t gfp)
+{
+	struct iwl_lq_sta *lq_sta;
+	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");
+
+	lq_sta = &sta_priv->lq_sta;
+
+	return lq_sta;
+}
+
+/*
+ * Called after adding a new station to initialize rate scaling
+ */
+void
+iwl4965_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++)
+			iwl4965_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++)
+			iwl4965_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 = iwl4965_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;
+
+	/* These values will be overridden later */
+	lq_sta->lq.general_params.single_stream_ant_msk =
+		iwl4965_first_antenna(priv->hw_params.valid_tx_ant);
+	lq_sta->lq.general_params.dual_stream_ant_msk =
+		priv->hw_params.valid_tx_ant &
+		~iwl4965_first_antenna(priv->hw_params.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 (iwl4965_num_of_ant(priv->hw_params.valid_tx_ant) == 2) {
+		lq_sta->lq.general_params.dual_stream_ant_msk =
+			priv->hw_params.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_MAC80211_DEBUGFS
+	lq_sta->dbg_fixed_rate = 0;
+#endif
+
+	iwl4965_rs_initialize_lq(priv, conf, sta, lq_sta);
+}
+
+static void iwl4965_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_link_quality_cmd *lq_cmd = &lq_sta->lq;
+
+	/* Override starting rate (index 0) if needed for debug purposes */
+	iwl4965_rs_dbgfs_set_mcs(lq_sta, &new_rate, index);
+
+	/* Interpret new_rate (rate_n_flags) */
+	iwl4965_rs_get_tbl_info_from_mcs(new_rate, lq_sta->band,
+				  &tbl_type, &rate_idx);
+
+	/* 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 = IWL_HT_NUMBER_TRY;
+	}
+
+	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 (iwl4965_num_of_ant(tbl_type.ant_type) == 1) {
+		lq_cmd->general_params.single_stream_ant_msk =
+						tbl_type.ant_type;
+	} else if (iwl4965_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)
+		valid_tx_ant = priv->hw_params.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 &&
+					 iwl4965_rs_toggle_antenna(valid_tx_ant,
+							&new_rate, &tbl_type))
+					ant_toggle_cnt = 1;
+			}
+
+			/* Override next rate if needed for debug purposes */
+			iwl4965_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++;
+		}
+
+		iwl4965_rs_get_tbl_info_from_mcs(new_rate,
+						lq_sta->band, &tbl_type,
+						&rate_idx);
+
+		/* 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 = iwl4965_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 &&
+				 iwl4965_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.
+		 * iwl4965_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 */
+		iwl4965_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 = 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);
+}
+
+static void
+*iwl4965_rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
+{
+	return hw->priv;
+}
+/* rate scale requires free function to be implemented */
+static void iwl4965_rs_free(void *priv_rate)
+{
+	return;
+}
+
+static void iwl4965_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 iwl4965_open_file_generic(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+static void iwl4965_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 = priv->hw_params.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 iwl4965_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];
+	int buf_size;
+	u32 parsed_rate;
+	struct iwl_station_priv *sta_priv =
+		container_of(lq_sta, struct iwl_station_priv, lq_sta);
+	struct iwl_rxon_context *ctx = sta_priv->common.ctx;
+
+	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;
+
+	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 */
+
+	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) {
+		iwl4965_rs_fill_link_cmd(NULL, lq_sta, lq_sta->dbg_fixed_rate);
+		iwl_legacy_send_lq_cmd(lq_sta->drv, ctx, &lq_sta->lq, CMD_ASYNC,
+				false);
+	}
+
+	return count;
+}
+
+static ssize_t iwl4965_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",
+	    (priv->hw_params.valid_tx_ant & ANT_A) ? "ANT_A," : "",
+	    (priv->hw_params.valid_tx_ant & ANT_B) ? "ANT_B," : "",
+	    (priv->hw_params.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" : "MIMO2");
+		   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 = iwl4965_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 = iwl4965_rs_sta_dbgfs_scale_table_write,
+	.read = iwl4965_rs_sta_dbgfs_scale_table_read,
+	.open = iwl4965_open_file_generic,
+	.llseek = default_llseek,
+};
+static ssize_t iwl4965_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 = iwl4965_rs_sta_dbgfs_stats_table_read,
+	.open = iwl4965_open_file_generic,
+	.llseek = default_llseek,
+};
+
+static ssize_t iwl4965_rs_sta_dbgfs_rate_scale_data_read(struct file *file,
+			char __user *user_buf, size_t count, loff_t *ppos)
+{
+	char buff[120];
+	int desc = 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;
+
+	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);
+
+	ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
+	return ret;
+}
+
+static const struct file_operations rs_sta_dbgfs_rate_scale_data_ops = {
+	.read = iwl4965_rs_sta_dbgfs_rate_scale_data_read,
+	.open = iwl4965_open_file_generic,
+	.llseek = default_llseek,
+};
+
+static void iwl4965_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 iwl4965_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
+iwl4965_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_4965_ops = {
+	.module = NULL,
+	.name = IWL4965_RS_NAME,
+	.tx_status = iwl4965_rs_tx_status,
+	.get_rate = iwl4965_rs_get_rate,
+	.rate_init = iwl4965_rs_rate_init_stub,
+	.alloc = iwl4965_rs_alloc,
+	.free = iwl4965_rs_free,
+	.alloc_sta = iwl4965_rs_alloc_sta,
+	.free_sta = iwl4965_rs_free_sta,
+#ifdef CONFIG_MAC80211_DEBUGFS
+	.add_sta_debugfs = iwl4965_rs_add_debugfs,
+	.remove_sta_debugfs = iwl4965_rs_remove_debugfs,
+#endif
+};
+
+int iwl4965_rate_control_register(void)
+{
+	pr_err("Registering 4965 rate control operations\n");
+	return ieee80211_rate_control_register(&rs_4965_ops);
+}
+
+void iwl4965_rate_control_unregister(void)
+{
+	ieee80211_rate_control_unregister(&rs_4965_ops);
+}