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1// SPDX-License-Identifier: GPL-2.0-only2/******************************************************************************3 *4 * Copyright(c) 2005 - 2011 Intel Corporation. All rights reserved.5 *6 * Contact Information:7 *  Intel Linux Wireless <ilw@linux.intel.com>8 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-64979 *10 *****************************************************************************/11 12#include <linux/kernel.h>13#include <linux/skbuff.h>14#include <linux/slab.h>15#include <net/mac80211.h>16 17#include <linux/netdevice.h>18#include <linux/etherdevice.h>19#include <linux/delay.h>20 21#include <linux/workqueue.h>22 23#include "commands.h"24#include "3945.h"25 26#define RS_NAME "iwl-3945-rs"27 28static s32 il3945_expected_tpt_g[RATE_COUNT_3945] = {29	7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 20230};31 32static s32 il3945_expected_tpt_g_prot[RATE_COUNT_3945] = {33	7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 12534};35 36static s32 il3945_expected_tpt_a[RATE_COUNT_3945] = {37	0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 18638};39 40static s32 il3945_expected_tpt_b[RATE_COUNT_3945] = {41	7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 042};43 44struct il3945_tpt_entry {45	s8 min_rssi;46	u8 idx;47};48 49static struct il3945_tpt_entry il3945_tpt_table_a[] = {50	{-60, RATE_54M_IDX},51	{-64, RATE_48M_IDX},52	{-72, RATE_36M_IDX},53	{-80, RATE_24M_IDX},54	{-84, RATE_18M_IDX},55	{-85, RATE_12M_IDX},56	{-87, RATE_9M_IDX},57	{-89, RATE_6M_IDX}58};59 60static struct il3945_tpt_entry il3945_tpt_table_g[] = {61	{-60, RATE_54M_IDX},62	{-64, RATE_48M_IDX},63	{-68, RATE_36M_IDX},64	{-80, RATE_24M_IDX},65	{-84, RATE_18M_IDX},66	{-85, RATE_12M_IDX},67	{-86, RATE_11M_IDX},68	{-88, RATE_5M_IDX},69	{-90, RATE_2M_IDX},70	{-92, RATE_1M_IDX}71};72 73#define RATE_MAX_WINDOW		6274#define RATE_FLUSH		(3*HZ)75#define RATE_WIN_FLUSH		(HZ/2)76#define IL39_RATE_HIGH_TH	1152077#define IL_SUCCESS_UP_TH	896078#define IL_SUCCESS_DOWN_TH	1088079#define RATE_MIN_FAILURE_TH	680#define RATE_MIN_SUCCESS_TH	881#define RATE_DECREASE_TH	192082#define RATE_RETRY_TH		1583 84static u885il3945_get_rate_idx_by_rssi(s32 rssi, enum nl80211_band band)86{87	u32 idx = 0;88	u32 table_size = 0;89	struct il3945_tpt_entry *tpt_table = NULL;90 91	if (rssi < IL_MIN_RSSI_VAL || rssi > IL_MAX_RSSI_VAL)92		rssi = IL_MIN_RSSI_VAL;93 94	switch (band) {95	case NL80211_BAND_2GHZ:96		tpt_table = il3945_tpt_table_g;97		table_size = ARRAY_SIZE(il3945_tpt_table_g);98		break;99	case NL80211_BAND_5GHZ:100		tpt_table = il3945_tpt_table_a;101		table_size = ARRAY_SIZE(il3945_tpt_table_a);102		break;103	default:104		BUG();105		break;106	}107 108	while (idx < table_size && rssi < tpt_table[idx].min_rssi)109		idx++;110 111	idx = min(idx, table_size - 1);112 113	return tpt_table[idx].idx;114}115 116static void117il3945_clear_win(struct il3945_rate_scale_data *win)118{119	win->data = 0;120	win->success_counter = 0;121	win->success_ratio = -1;122	win->counter = 0;123	win->average_tpt = IL_INVALID_VALUE;124	win->stamp = 0;125}126 127/*128 * il3945_rate_scale_flush_wins - flush out the rate scale wins129 *130 * Returns the number of wins that have gathered data but were131 * not flushed.  If there were any that were not flushed, then132 * reschedule the rate flushing routine.133 */134static int135il3945_rate_scale_flush_wins(struct il3945_rs_sta *rs_sta)136{137	int unflushed = 0;138	int i;139	unsigned long flags;140	struct il_priv *il __maybe_unused = rs_sta->il;141 142	/*143	 * For each rate, if we have collected data on that rate144	 * and it has been more than RATE_WIN_FLUSH145	 * since we flushed, clear out the gathered stats146	 */147	for (i = 0; i < RATE_COUNT_3945; i++) {148		if (!rs_sta->win[i].counter)149			continue;150 151		spin_lock_irqsave(&rs_sta->lock, flags);152		if (time_after(jiffies, rs_sta->win[i].stamp + RATE_WIN_FLUSH)) {153			D_RATE("flushing %d samples of rate " "idx %d\n",154			       rs_sta->win[i].counter, i);155			il3945_clear_win(&rs_sta->win[i]);156		} else157			unflushed++;158		spin_unlock_irqrestore(&rs_sta->lock, flags);159	}160 161	return unflushed;162}163 164#define RATE_FLUSH_MAX              5000	/* msec */165#define RATE_FLUSH_MIN              50	/* msec */166#define IL_AVERAGE_PACKETS             1500167 168static void169il3945_bg_rate_scale_flush(struct timer_list *t)170{171	struct il3945_rs_sta *rs_sta = from_timer(rs_sta, t, rate_scale_flush);172	struct il_priv *il __maybe_unused = rs_sta->il;173	int unflushed = 0;174	unsigned long flags;175	u32 packet_count, duration, pps;176 177	D_RATE("enter\n");178 179	unflushed = il3945_rate_scale_flush_wins(rs_sta);180 181	spin_lock_irqsave(&rs_sta->lock, flags);182 183	/* Number of packets Rx'd since last time this timer ran */184	packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;185 186	rs_sta->last_tx_packets = rs_sta->tx_packets + 1;187 188	if (unflushed) {189		duration =190		    jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);191 192		D_RATE("Tx'd %d packets in %dms\n", packet_count, duration);193 194		/* Determine packets per second */195		if (duration)196			pps = (packet_count * 1000) / duration;197		else198			pps = 0;199 200		if (pps) {201			duration = (IL_AVERAGE_PACKETS * 1000) / pps;202			if (duration < RATE_FLUSH_MIN)203				duration = RATE_FLUSH_MIN;204			else if (duration > RATE_FLUSH_MAX)205				duration = RATE_FLUSH_MAX;206		} else207			duration = RATE_FLUSH_MAX;208 209		rs_sta->flush_time = msecs_to_jiffies(duration);210 211		D_RATE("new flush period: %d msec ave %d\n", duration,212		       packet_count);213 214		mod_timer(&rs_sta->rate_scale_flush,215			  jiffies + rs_sta->flush_time);216 217		rs_sta->last_partial_flush = jiffies;218	} else {219		rs_sta->flush_time = RATE_FLUSH;220		rs_sta->flush_pending = 0;221	}222	/* If there weren't any unflushed entries, we don't schedule the timer223	 * to run again */224 225	rs_sta->last_flush = jiffies;226 227	spin_unlock_irqrestore(&rs_sta->lock, flags);228 229	D_RATE("leave\n");230}231 232/*233 * il3945_collect_tx_data - Update the success/failure sliding win234 *235 * We keep a sliding win of the last 64 packets transmitted236 * at this rate.  win->data contains the bitmask of successful237 * packets.238 */239static void240il3945_collect_tx_data(struct il3945_rs_sta *rs_sta,241		       struct il3945_rate_scale_data *win, int success,242		       int retries, int idx)243{244	unsigned long flags;245	s32 fail_count;246	struct il_priv *il __maybe_unused = rs_sta->il;247 248	if (!retries) {249		D_RATE("leave: retries == 0 -- should be at least 1\n");250		return;251	}252 253	spin_lock_irqsave(&rs_sta->lock, flags);254 255	/*256	 * Keep track of only the latest 62 tx frame attempts in this rate's257	 * history win; anything older isn't really relevant any more.258	 * If we have filled up the sliding win, drop the oldest attempt;259	 * if the oldest attempt (highest bit in bitmap) shows "success",260	 * subtract "1" from the success counter (this is the main reason261	 * we keep these bitmaps!).262	 * */263	while (retries > 0) {264		if (win->counter >= RATE_MAX_WINDOW) {265 266			/* remove earliest */267			win->counter = RATE_MAX_WINDOW - 1;268 269			if (win->data & (1ULL << (RATE_MAX_WINDOW - 1))) {270				win->data &= ~(1ULL << (RATE_MAX_WINDOW - 1));271				win->success_counter--;272			}273		}274 275		/* Increment frames-attempted counter */276		win->counter++;277 278		/* Shift bitmap by one frame (throw away oldest history),279		 * OR in "1", and increment "success" if this280		 * frame was successful. */281		win->data <<= 1;282		if (success > 0) {283			win->success_counter++;284			win->data |= 0x1;285			success--;286		}287 288		retries--;289	}290 291	/* Calculate current success ratio, avoid divide-by-0! */292	if (win->counter > 0)293		win->success_ratio =294		    128 * (100 * win->success_counter) / win->counter;295	else296		win->success_ratio = IL_INVALID_VALUE;297 298	fail_count = win->counter - win->success_counter;299 300	/* Calculate average throughput, if we have enough history. */301	if (fail_count >= RATE_MIN_FAILURE_TH ||302	    win->success_counter >= RATE_MIN_SUCCESS_TH)303		win->average_tpt =304		    ((win->success_ratio * rs_sta->expected_tpt[idx] +305		      64) / 128);306	else307		win->average_tpt = IL_INVALID_VALUE;308 309	/* Tag this win as having been updated */310	win->stamp = jiffies;311 312	spin_unlock_irqrestore(&rs_sta->lock, flags);313}314 315/*316 * Called after adding a new station to initialize rate scaling317 */318void319il3945_rs_rate_init(struct il_priv *il, struct ieee80211_sta *sta, u8 sta_id)320{321	struct ieee80211_hw *hw = il->hw;322	struct ieee80211_conf *conf = &il->hw->conf;323	struct il3945_sta_priv *psta;324	struct il3945_rs_sta *rs_sta;325	struct ieee80211_supported_band *sband;326	int i;327 328	D_INFO("enter\n");329	if (sta_id == il->hw_params.bcast_id)330		goto out;331 332	psta = (struct il3945_sta_priv *)sta->drv_priv;333	rs_sta = &psta->rs_sta;334	sband = hw->wiphy->bands[conf->chandef.chan->band];335 336	rs_sta->il = il;337 338	rs_sta->start_rate = RATE_INVALID;339 340	/* default to just 802.11b */341	rs_sta->expected_tpt = il3945_expected_tpt_b;342 343	rs_sta->last_partial_flush = jiffies;344	rs_sta->last_flush = jiffies;345	rs_sta->flush_time = RATE_FLUSH;346	rs_sta->last_tx_packets = 0;347 348	for (i = 0; i < RATE_COUNT_3945; i++)349		il3945_clear_win(&rs_sta->win[i]);350 351	/* TODO: what is a good starting rate for STA? About middle? Maybe not352	 * the lowest or the highest rate.. Could consider using RSSI from353	 * previous packets? Need to have IEEE 802.1X auth succeed immediately354	 * after assoc.. */355 356	for (i = sband->n_bitrates - 1; i >= 0; i--) {357		if (sta->deflink.supp_rates[sband->band] & (1 << i)) {358			rs_sta->last_txrate_idx = i;359			break;360		}361	}362 363	il->_3945.sta_supp_rates = sta->deflink.supp_rates[sband->band];364	/* For 5 GHz band it start at IL_FIRST_OFDM_RATE */365	if (sband->band == NL80211_BAND_5GHZ) {366		rs_sta->last_txrate_idx += IL_FIRST_OFDM_RATE;367		il->_3945.sta_supp_rates <<= IL_FIRST_OFDM_RATE;368	}369 370out:371	il->stations[sta_id].used &= ~IL_STA_UCODE_INPROGRESS;372 373	D_INFO("leave\n");374}375 376static void *377il3945_rs_alloc(struct ieee80211_hw *hw)378{379	return hw->priv;380}381 382/* rate scale requires free function to be implemented */383static void384il3945_rs_free(void *il)385{386}387 388static void *389il3945_rs_alloc_sta(void *il_priv, struct ieee80211_sta *sta, gfp_t gfp)390{391	struct il3945_rs_sta *rs_sta;392	struct il3945_sta_priv *psta = (void *)sta->drv_priv;393	struct il_priv *il __maybe_unused = il_priv;394 395	D_RATE("enter\n");396 397	rs_sta = &psta->rs_sta;398 399	spin_lock_init(&rs_sta->lock);400	timer_setup(&rs_sta->rate_scale_flush, il3945_bg_rate_scale_flush, 0);401	D_RATE("leave\n");402 403	return rs_sta;404}405 406static void407il3945_rs_free_sta(void *il_priv, struct ieee80211_sta *sta, void *il_sta)408{409	struct il3945_rs_sta *rs_sta = il_sta;410 411	/*412	 * Be careful not to use any members of il3945_rs_sta (like trying413	 * to use il_priv to print out debugging) since it may not be fully414	 * initialized at this point.415	 */416	del_timer_sync(&rs_sta->rate_scale_flush);417}418 419/*420 * il3945_rs_tx_status - Update rate control values based on Tx results421 *422 * NOTE: Uses il_priv->retry_rate for the # of retries attempted by423 * the hardware for each rate.424 */425static void426il3945_rs_tx_status(void *il_rate, struct ieee80211_supported_band *sband,427		    struct ieee80211_sta *sta, void *il_sta,428		    struct sk_buff *skb)429{430	s8 retries = 0, current_count;431	int scale_rate_idx, first_idx, last_idx;432	unsigned long flags;433	struct il_priv *il = (struct il_priv *)il_rate;434	struct il3945_rs_sta *rs_sta = il_sta;435	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);436 437	D_RATE("enter\n");438 439	retries = info->status.rates[0].count;440	/* Sanity Check for retries */441	if (retries > RATE_RETRY_TH)442		retries = RATE_RETRY_TH;443 444	first_idx = sband->bitrates[info->status.rates[0].idx].hw_value;445	if (first_idx < 0 || first_idx >= RATE_COUNT_3945) {446		D_RATE("leave: Rate out of bounds: %d\n", first_idx);447		return;448	}449 450	if (!il_sta) {451		D_RATE("leave: No STA il data to update!\n");452		return;453	}454 455	/* Treat uninitialized rate scaling data same as non-existing. */456	if (!rs_sta->il) {457		D_RATE("leave: STA il data uninitialized!\n");458		return;459	}460 461	rs_sta->tx_packets++;462 463	scale_rate_idx = first_idx;464	last_idx = first_idx;465 466	/*467	 * Update the win for each rate.  We determine which rates468	 * were Tx'd based on the total number of retries vs. the number469	 * of retries configured for each rate -- currently set to the470	 * il value 'retry_rate' vs. rate specific471	 *472	 * On exit from this while loop last_idx indicates the rate473	 * at which the frame was finally transmitted (or failed if no474	 * ACK)475	 */476	while (retries > 1) {477		if ((retries - 1) < il->retry_rate) {478			current_count = (retries - 1);479			last_idx = scale_rate_idx;480		} else {481			current_count = il->retry_rate;482			last_idx = il3945_rs_next_rate(il, scale_rate_idx);483		}484 485		/* Update this rate accounting for as many retries486		 * as was used for it (per current_count) */487		il3945_collect_tx_data(rs_sta, &rs_sta->win[scale_rate_idx], 0,488				       current_count, scale_rate_idx);489		D_RATE("Update rate %d for %d retries.\n", scale_rate_idx,490		       current_count);491 492		retries -= current_count;493 494		scale_rate_idx = last_idx;495	}496 497	/* Update the last idx win with success/failure based on ACK */498	D_RATE("Update rate %d with %s.\n", last_idx,499	       (info->flags & IEEE80211_TX_STAT_ACK) ? "success" : "failure");500	il3945_collect_tx_data(rs_sta, &rs_sta->win[last_idx],501			       info->flags & IEEE80211_TX_STAT_ACK, 1,502			       last_idx);503 504	/* We updated the rate scale win -- if its been more than505	 * flush_time since the last run, schedule the flush506	 * again */507	spin_lock_irqsave(&rs_sta->lock, flags);508 509	if (!rs_sta->flush_pending &&510	    time_after(jiffies, rs_sta->last_flush + rs_sta->flush_time)) {511 512		rs_sta->last_partial_flush = jiffies;513		rs_sta->flush_pending = 1;514		mod_timer(&rs_sta->rate_scale_flush,515			  jiffies + rs_sta->flush_time);516	}517 518	spin_unlock_irqrestore(&rs_sta->lock, flags);519 520	D_RATE("leave\n");521}522 523static u16524il3945_get_adjacent_rate(struct il3945_rs_sta *rs_sta, u8 idx, u16 rate_mask,525			 enum nl80211_band band)526{527	u8 high = RATE_INVALID;528	u8 low = RATE_INVALID;529	struct il_priv *il __maybe_unused = rs_sta->il;530 531	/* 802.11A walks to the next literal adjacent rate in532	 * the rate table */533	if (unlikely(band == NL80211_BAND_5GHZ)) {534		int i;535		u32 mask;536 537		/* Find the previous rate that is in the rate mask */538		i = idx - 1;539		for (mask = (1 << i); i >= 0; i--, mask >>= 1) {540			if (rate_mask & mask) {541				low = i;542				break;543			}544		}545 546		/* Find the next rate that is in the rate mask */547		i = idx + 1;548		for (mask = (1 << i); i < RATE_COUNT_3945; i++, mask <<= 1) {549			if (rate_mask & mask) {550				high = i;551				break;552			}553		}554 555		return (high << 8) | low;556	}557 558	low = idx;559	while (low != RATE_INVALID) {560		if (rs_sta->tgg)561			low = il3945_rates[low].prev_rs_tgg;562		else563			low = il3945_rates[low].prev_rs;564		if (low == RATE_INVALID)565			break;566		if (rate_mask & (1 << low))567			break;568		D_RATE("Skipping masked lower rate: %d\n", low);569	}570 571	high = idx;572	while (high != RATE_INVALID) {573		if (rs_sta->tgg)574			high = il3945_rates[high].next_rs_tgg;575		else576			high = il3945_rates[high].next_rs;577		if (high == RATE_INVALID)578			break;579		if (rate_mask & (1 << high))580			break;581		D_RATE("Skipping masked higher rate: %d\n", high);582	}583 584	return (high << 8) | low;585}586 587/*588 * il3945_rs_get_rate - find the rate for the requested packet589 *590 * Returns the ieee80211_rate structure allocated by the driver.591 *592 * The rate control algorithm has no internal mapping between hw_mode's593 * rate ordering and the rate ordering used by the rate control algorithm.594 *595 * The rate control algorithm uses a single table of rates that goes across596 * the entire A/B/G spectrum vs. being limited to just one particular597 * hw_mode.598 *599 * As such, we can't convert the idx obtained below into the hw_mode's600 * rate table and must reference the driver allocated rate table601 *602 */603static void604il3945_rs_get_rate(void *il_r, struct ieee80211_sta *sta, void *il_sta,605		   struct ieee80211_tx_rate_control *txrc)606{607	struct ieee80211_supported_band *sband = txrc->sband;608	struct sk_buff *skb = txrc->skb;609	u8 low = RATE_INVALID;610	u8 high = RATE_INVALID;611	u16 high_low;612	int idx;613	struct il3945_rs_sta *rs_sta = il_sta;614	struct il3945_rate_scale_data *win = NULL;615	int current_tpt = IL_INVALID_VALUE;616	int low_tpt = IL_INVALID_VALUE;617	int high_tpt = IL_INVALID_VALUE;618	u32 fail_count;619	s8 scale_action = 0;620	unsigned long flags;621	u16 rate_mask;622	s8 max_rate_idx = -1;623	struct il_priv *il __maybe_unused = (struct il_priv *)il_r;624	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);625 626	D_RATE("enter\n");627 628	/* Treat uninitialized rate scaling data same as non-existing. */629	if (rs_sta && !rs_sta->il) {630		D_RATE("Rate scaling information not initialized yet.\n");631		il_sta = NULL;632	}633 634	rate_mask = sta->deflink.supp_rates[sband->band];635 636	/* get user max rate if set */637	max_rate_idx = fls(txrc->rate_idx_mask) - 1;638	if (sband->band == NL80211_BAND_5GHZ && max_rate_idx != -1)639		max_rate_idx += IL_FIRST_OFDM_RATE;640	if (max_rate_idx < 0 || max_rate_idx >= RATE_COUNT)641		max_rate_idx = -1;642 643	idx = min(rs_sta->last_txrate_idx & 0xffff, RATE_COUNT_3945 - 1);644 645	if (sband->band == NL80211_BAND_5GHZ)646		rate_mask = rate_mask << IL_FIRST_OFDM_RATE;647 648	spin_lock_irqsave(&rs_sta->lock, flags);649 650	/* for recent assoc, choose best rate regarding651	 * to rssi value652	 */653	if (rs_sta->start_rate != RATE_INVALID) {654		if (rs_sta->start_rate < idx &&655		    (rate_mask & (1 << rs_sta->start_rate)))656			idx = rs_sta->start_rate;657		rs_sta->start_rate = RATE_INVALID;658	}659 660	/* force user max rate if set by user */661	if (max_rate_idx != -1 && max_rate_idx < idx) {662		if (rate_mask & (1 << max_rate_idx))663			idx = max_rate_idx;664	}665 666	win = &(rs_sta->win[idx]);667 668	fail_count = win->counter - win->success_counter;669 670	if (fail_count < RATE_MIN_FAILURE_TH &&671	    win->success_counter < RATE_MIN_SUCCESS_TH) {672		spin_unlock_irqrestore(&rs_sta->lock, flags);673 674		D_RATE("Invalid average_tpt on rate %d: "675		       "counter: %d, success_counter: %d, "676		       "expected_tpt is %sNULL\n", idx, win->counter,677		       win->success_counter,678		       rs_sta->expected_tpt ? "not " : "");679 680		/* Can't calculate this yet; not enough history */681		win->average_tpt = IL_INVALID_VALUE;682		goto out;683 684	}685 686	current_tpt = win->average_tpt;687 688	high_low =689	    il3945_get_adjacent_rate(rs_sta, idx, rate_mask, sband->band);690	low = high_low & 0xff;691	high = (high_low >> 8) & 0xff;692 693	/* If user set max rate, dont allow higher than user constrain */694	if (max_rate_idx != -1 && max_rate_idx < high)695		high = RATE_INVALID;696 697	/* Collect Measured throughputs of adjacent rates */698	if (low != RATE_INVALID)699		low_tpt = rs_sta->win[low].average_tpt;700 701	if (high != RATE_INVALID)702		high_tpt = rs_sta->win[high].average_tpt;703 704	spin_unlock_irqrestore(&rs_sta->lock, flags);705 706	scale_action = 0;707 708	/* Low success ratio , need to drop the rate */709	if (win->success_ratio < RATE_DECREASE_TH || !current_tpt) {710		D_RATE("decrease rate because of low success_ratio\n");711		scale_action = -1;712		/* No throughput measured yet for adjacent rates,713		 * try increase */714	} else if (low_tpt == IL_INVALID_VALUE && high_tpt == IL_INVALID_VALUE) {715 716		if (high != RATE_INVALID &&717		    win->success_ratio >= RATE_INCREASE_TH)718			scale_action = 1;719		else if (low != RATE_INVALID)720			scale_action = 0;721 722		/* Both adjacent throughputs are measured, but neither one has723		 * better throughput; we're using the best rate, don't change724		 * it! */725	} else if (low_tpt != IL_INVALID_VALUE && high_tpt != IL_INVALID_VALUE726		   && low_tpt < current_tpt && high_tpt < current_tpt) {727 728		D_RATE("No action -- low [%d] & high [%d] < "729		       "current_tpt [%d]\n", low_tpt, high_tpt, current_tpt);730		scale_action = 0;731 732		/* At least one of the rates has better throughput */733	} else {734		if (high_tpt != IL_INVALID_VALUE) {735 736			/* High rate has better throughput, Increase737			 * rate */738			if (high_tpt > current_tpt &&739			    win->success_ratio >= RATE_INCREASE_TH)740				scale_action = 1;741			else {742				D_RATE("decrease rate because of high tpt\n");743				scale_action = 0;744			}745		} else if (low_tpt != IL_INVALID_VALUE) {746			if (low_tpt > current_tpt) {747				D_RATE("decrease rate because of low tpt\n");748				scale_action = -1;749			} else if (win->success_ratio >= RATE_INCREASE_TH) {750				/* Lower rate has better751				 * throughput,decrease rate */752				scale_action = 1;753			}754		}755	}756 757	/* Sanity check; asked for decrease, but success rate or throughput758	 * has been good at old rate.  Don't change it. */759	if (scale_action == -1 && low != RATE_INVALID &&760	    (win->success_ratio > RATE_HIGH_TH ||761	     current_tpt > 100 * rs_sta->expected_tpt[low]))762		scale_action = 0;763 764	switch (scale_action) {765	case -1:766		/* Decrease rate */767		if (low != RATE_INVALID)768			idx = low;769		break;770	case 1:771		/* Increase rate */772		if (high != RATE_INVALID)773			idx = high;774 775		break;776	case 0:777	default:778		/* No change */779		break;780	}781 782	D_RATE("Selected %d (action %d) - low %d high %d\n", idx, scale_action,783	       low, high);784 785out:786 787	if (sband->band == NL80211_BAND_5GHZ) {788		if (WARN_ON_ONCE(idx < IL_FIRST_OFDM_RATE))789			idx = IL_FIRST_OFDM_RATE;790		rs_sta->last_txrate_idx = idx;791		info->control.rates[0].idx = idx - IL_FIRST_OFDM_RATE;792	} else {793		rs_sta->last_txrate_idx = idx;794		info->control.rates[0].idx = rs_sta->last_txrate_idx;795	}796	info->control.rates[0].count = 1;797 798	D_RATE("leave: %d\n", idx);799}800 801#ifdef CONFIG_MAC80211_DEBUGFS802 803static ssize_t804il3945_sta_dbgfs_stats_table_read(struct file *file, char __user *user_buf,805				  size_t count, loff_t *ppos)806{807	char *buff;808	int desc = 0;809	int j;810	ssize_t ret;811	struct il3945_rs_sta *lq_sta = file->private_data;812 813	buff = kmalloc(1024, GFP_KERNEL);814	if (!buff)815		return -ENOMEM;816 817	desc +=818	    sprintf(buff + desc,819		    "tx packets=%d last rate idx=%d\n"820		    "rate=0x%X flush time %d\n", lq_sta->tx_packets,821		    lq_sta->last_txrate_idx, lq_sta->start_rate,822		    jiffies_to_msecs(lq_sta->flush_time));823	for (j = 0; j < RATE_COUNT_3945; j++) {824		desc +=825		    sprintf(buff + desc, "counter=%d success=%d %%=%d\n",826			    lq_sta->win[j].counter,827			    lq_sta->win[j].success_counter,828			    lq_sta->win[j].success_ratio);829	}830	ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);831	kfree(buff);832	return ret;833}834 835static const struct file_operations rs_sta_dbgfs_stats_table_ops = {836	.read = il3945_sta_dbgfs_stats_table_read,837	.open = simple_open,838	.llseek = default_llseek,839};840 841static void842il3945_add_debugfs(void *il, void *il_sta, struct dentry *dir)843{844	struct il3945_rs_sta *lq_sta = il_sta;845 846	debugfs_create_file("rate_stats_table", 0600, dir, lq_sta,847			    &rs_sta_dbgfs_stats_table_ops);848}849#endif850 851/*852 * Initialization of rate scaling information is done by driver after853 * the station is added. Since mac80211 calls this function before a854 * station is added we ignore it.855 */856static void857il3945_rs_rate_init_stub(void *il_r, struct ieee80211_supported_band *sband,858			 struct cfg80211_chan_def *chandef,859			 struct ieee80211_sta *sta, void *il_sta)860{861}862 863static const struct rate_control_ops rs_ops = {864	.name = RS_NAME,865	.tx_status = il3945_rs_tx_status,866	.get_rate = il3945_rs_get_rate,867	.rate_init = il3945_rs_rate_init_stub,868	.alloc = il3945_rs_alloc,869	.free = il3945_rs_free,870	.alloc_sta = il3945_rs_alloc_sta,871	.free_sta = il3945_rs_free_sta,872#ifdef CONFIG_MAC80211_DEBUGFS873	.add_sta_debugfs = il3945_add_debugfs,874#endif875 876};877 878void879il3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)880{881	struct il_priv *il = hw->priv;882	s32 rssi = 0;883	unsigned long flags;884	struct il3945_rs_sta *rs_sta;885	struct ieee80211_sta *sta;886	struct il3945_sta_priv *psta;887 888	D_RATE("enter\n");889 890	rcu_read_lock();891 892	sta = ieee80211_find_sta(il->vif, il->stations[sta_id].sta.sta.addr);893	if (!sta) {894		D_RATE("Unable to find station to initialize rate scaling.\n");895		rcu_read_unlock();896		return;897	}898 899	psta = (void *)sta->drv_priv;900	rs_sta = &psta->rs_sta;901 902	spin_lock_irqsave(&rs_sta->lock, flags);903 904	rs_sta->tgg = 0;905	switch (il->band) {906	case NL80211_BAND_2GHZ:907		/* TODO: this always does G, not a regression */908		if (il->active.flags & RXON_FLG_TGG_PROTECT_MSK) {909			rs_sta->tgg = 1;910			rs_sta->expected_tpt = il3945_expected_tpt_g_prot;911		} else912			rs_sta->expected_tpt = il3945_expected_tpt_g;913		break;914	case NL80211_BAND_5GHZ:915		rs_sta->expected_tpt = il3945_expected_tpt_a;916		break;917	default:918		BUG();919		break;920	}921 922	spin_unlock_irqrestore(&rs_sta->lock, flags);923 924	rssi = il->_3945.last_rx_rssi;925	if (rssi == 0)926		rssi = IL_MIN_RSSI_VAL;927 928	D_RATE("Network RSSI: %d\n", rssi);929 930	rs_sta->start_rate = il3945_get_rate_idx_by_rssi(rssi, il->band);931 932	D_RATE("leave: rssi %d assign rate idx: " "%d (plcp 0x%x)\n", rssi,933	       rs_sta->start_rate, il3945_rates[rs_sta->start_rate].plcp);934	rcu_read_unlock();935}936 937int938il3945_rate_control_register(void)939{940	return ieee80211_rate_control_register(&rs_ops);941}942 943void944il3945_rate_control_unregister(void)945{946	ieee80211_rate_control_unregister(&rs_ops);947}948