1/* 2 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * Based on minstrel.c: 9 * Copyright (C) 2005-2007 Derek Smithies <derek@indranet.co.nz> 10 * Sponsored by Indranet Technologies Ltd 11 * 12 * Based on sample.c: 13 * Copyright (c) 2005 John Bicket 14 * All rights reserved. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer, 21 * without modification. 22 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 23 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any 24 * redistribution must be conditioned upon including a substantially 25 * similar Disclaimer requirement for further binary redistribution. 26 * 3. Neither the names of the above-listed copyright holders nor the names 27 * of any contributors may be used to endorse or promote products derived 28 * from this software without specific prior written permission. 29 * 30 * Alternatively, this software may be distributed under the terms of the 31 * GNU General Public License ("GPL") version 2 as published by the Free 32 * Software Foundation. 33 * 34 * NO WARRANTY 35 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 36 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 37 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY 38 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 39 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, 40 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 41 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 42 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 43 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 44 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 45 * THE POSSIBILITY OF SUCH DAMAGES. 46 */ 47#include <linux/netdevice.h> 48#include <linux/types.h> 49#include <linux/skbuff.h> 50#include <linux/debugfs.h> 51#include <linux/random.h> 52#include <linux/ieee80211.h> 53#include <linux/slab.h> 54#include <net/mac80211.h> 55#include "rate.h" 56#include "rc80211_minstrel.h" 57 58#define SAMPLE_TBL(_mi, _idx, _col) \ 59 _mi->sample_table[(_idx * SAMPLE_COLUMNS) + _col] 60 61/* convert mac80211 rate index to local array index */ 62static inline int 63rix_to_ndx(struct minstrel_sta_info *mi, int rix) 64{ 65 int i = rix; 66 for (i = rix; i >= 0; i--) 67 if (mi->r[i].rix == rix) 68 break; 69 return i; 70} 71 72/* find & sort topmost throughput rates */ 73static inline void 74minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list) 75{ 76 int j = MAX_THR_RATES; 77 78 while (j > 0 && mi->r[i].stats.cur_tp > mi->r[tp_list[j - 1]].stats.cur_tp) 79 j--; 80 if (j < MAX_THR_RATES - 1) 81 memmove(&tp_list[j + 1], &tp_list[j], MAX_THR_RATES - (j + 1)); 82 if (j < MAX_THR_RATES) 83 tp_list[j] = i; 84} 85 86static void 87minstrel_set_rate(struct minstrel_sta_info *mi, struct ieee80211_sta_rates *ratetbl, 88 int offset, int idx) 89{ 90 struct minstrel_rate *r = &mi->r[idx]; 91 92 ratetbl->rate[offset].idx = r->rix; 93 ratetbl->rate[offset].count = r->adjusted_retry_count; 94 ratetbl->rate[offset].count_cts = r->retry_count_cts; 95 ratetbl->rate[offset].count_rts = r->stats.retry_count_rtscts; 96} 97 98static void 99minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi) 100{ 101 struct ieee80211_sta_rates *ratetbl; 102 int i = 0; 103 104 ratetbl = kzalloc(sizeof(*ratetbl), GFP_ATOMIC); 105 if (!ratetbl) 106 return; 107 108 /* Start with max_tp_rate */ 109 minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[0]); 110 111 if (mp->hw->max_rates >= 3) { 112 /* At least 3 tx rates supported, use max_tp_rate2 next */ 113 minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[1]); 114 } 115 116 if (mp->hw->max_rates >= 2) { 117 /* At least 2 tx rates supported, use max_prob_rate next */ 118 minstrel_set_rate(mi, ratetbl, i++, mi->max_prob_rate); 119 } 120 121 /* Use lowest rate last */ 122 ratetbl->rate[i].idx = mi->lowest_rix; 123 ratetbl->rate[i].count = mp->max_retry; 124 ratetbl->rate[i].count_cts = mp->max_retry; 125 ratetbl->rate[i].count_rts = mp->max_retry; 126 127 rate_control_set_rates(mp->hw, mi->sta, ratetbl); 128} 129 130static void 131minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) 132{ 133 u8 tmp_tp_rate[MAX_THR_RATES]; 134 u8 tmp_prob_rate = 0; 135 u32 usecs; 136 int i; 137 138 for (i = 0; i < MAX_THR_RATES; i++) 139 tmp_tp_rate[i] = 0; 140 141 for (i = 0; i < mi->n_rates; i++) { 142 struct minstrel_rate *mr = &mi->r[i]; 143 struct minstrel_rate_stats *mrs = &mi->r[i].stats; 144 145 usecs = mr->perfect_tx_time; 146 if (!usecs) 147 usecs = 1000000; 148 149 if (unlikely(mrs->attempts > 0)) { 150 mrs->sample_skipped = 0; 151 mrs->cur_prob = MINSTREL_FRAC(mrs->success, 152 mrs->attempts); 153 mrs->succ_hist += mrs->success; 154 mrs->att_hist += mrs->attempts; 155 mrs->probability = minstrel_ewma(mrs->probability, 156 mrs->cur_prob, 157 EWMA_LEVEL); 158 } else 159 mrs->sample_skipped++; 160 161 mrs->last_success = mrs->success; 162 mrs->last_attempts = mrs->attempts; 163 mrs->success = 0; 164 mrs->attempts = 0; 165 166 /* Update throughput per rate, reset thr. below 10% success */ 167 if (mrs->probability < MINSTREL_FRAC(10, 100)) 168 mrs->cur_tp = 0; 169 else 170 mrs->cur_tp = mrs->probability * (1000000 / usecs); 171 172 /* Sample less often below the 10% chance of success. 173 * Sample less often above the 95% chance of success. */ 174 if (mrs->probability > MINSTREL_FRAC(95, 100) || 175 mrs->probability < MINSTREL_FRAC(10, 100)) { 176 mr->adjusted_retry_count = mrs->retry_count >> 1; 177 if (mr->adjusted_retry_count > 2) 178 mr->adjusted_retry_count = 2; 179 mr->sample_limit = 4; 180 } else { 181 mr->sample_limit = -1; 182 mr->adjusted_retry_count = mrs->retry_count; 183 } 184 if (!mr->adjusted_retry_count) 185 mr->adjusted_retry_count = 2; 186 187 minstrel_sort_best_tp_rates(mi, i, tmp_tp_rate); 188 189 /* To determine the most robust rate (max_prob_rate) used at 190 * 3rd mmr stage we distinct between two cases: 191 * (1) if any success probabilitiy >= 95%, out of those rates 192 * choose the maximum throughput rate as max_prob_rate 193 * (2) if all success probabilities < 95%, the rate with 194 * highest success probability is choosen as max_prob_rate */ 195 if (mrs->probability >= MINSTREL_FRAC(95, 100)) { 196 if (mrs->cur_tp >= mi->r[tmp_prob_rate].stats.cur_tp) 197 tmp_prob_rate = i; 198 } else { 199 if (mrs->probability >= mi->r[tmp_prob_rate].stats.probability) 200 tmp_prob_rate = i; 201 } 202 } 203 204 /* Assign the new rate set */ 205 memcpy(mi->max_tp_rate, tmp_tp_rate, sizeof(mi->max_tp_rate)); 206 mi->max_prob_rate = tmp_prob_rate; 207 208#ifdef CONFIG_MAC80211_DEBUGFS 209 /* use fixed index if set */ 210 if (mp->fixed_rate_idx != -1) { 211 mi->max_tp_rate[0] = mp->fixed_rate_idx; 212 mi->max_tp_rate[1] = mp->fixed_rate_idx; 213 mi->max_prob_rate = mp->fixed_rate_idx; 214 } 215#endif 216 217 /* Reset update timer */ 218 mi->stats_update = jiffies; 219 220 minstrel_update_rates(mp, mi); 221} 222 223static void 224minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband, 225 struct ieee80211_sta *sta, void *priv_sta, 226 struct sk_buff *skb) 227{ 228 struct minstrel_priv *mp = priv; 229 struct minstrel_sta_info *mi = priv_sta; 230 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 231 struct ieee80211_tx_rate *ar = info->status.rates; 232 int i, ndx; 233 int success; 234 235 success = !!(info->flags & IEEE80211_TX_STAT_ACK); 236 237 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { 238 if (ar[i].idx < 0) 239 break; 240 241 ndx = rix_to_ndx(mi, ar[i].idx); 242 if (ndx < 0) 243 continue; 244 245 mi->r[ndx].stats.attempts += ar[i].count; 246 247 if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0)) 248 mi->r[ndx].stats.success += success; 249 } 250 251 if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) 252 mi->sample_packets++; 253 254 if (mi->sample_deferred > 0) 255 mi->sample_deferred--; 256 257 if (time_after(jiffies, mi->stats_update + 258 (mp->update_interval * HZ) / 1000)) 259 minstrel_update_stats(mp, mi); 260} 261 262 263static inline unsigned int 264minstrel_get_retry_count(struct minstrel_rate *mr, 265 struct ieee80211_tx_info *info) 266{ 267 unsigned int retry = mr->adjusted_retry_count; 268 269 if (info->control.use_rts) 270 retry = max(2U, min(mr->stats.retry_count_rtscts, retry)); 271 else if (info->control.use_cts_prot) 272 retry = max(2U, min(mr->retry_count_cts, retry)); 273 return retry; 274} 275 276 277static int 278minstrel_get_next_sample(struct minstrel_sta_info *mi) 279{ 280 unsigned int sample_ndx; 281 sample_ndx = SAMPLE_TBL(mi, mi->sample_row, mi->sample_column); 282 mi->sample_row++; 283 if ((int) mi->sample_row >= mi->n_rates) { 284 mi->sample_row = 0; 285 mi->sample_column++; 286 if (mi->sample_column >= SAMPLE_COLUMNS) 287 mi->sample_column = 0; 288 } 289 return sample_ndx; 290} 291 292static void 293minstrel_get_rate(void *priv, struct ieee80211_sta *sta, 294 void *priv_sta, struct ieee80211_tx_rate_control *txrc) 295{ 296 struct sk_buff *skb = txrc->skb; 297 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); 298 struct minstrel_sta_info *mi = priv_sta; 299 struct minstrel_priv *mp = priv; 300 struct ieee80211_tx_rate *rate = &info->control.rates[0]; 301 struct minstrel_rate *msr, *mr; 302 unsigned int ndx; 303 bool mrr_capable; 304 bool prev_sample; 305 int delta; 306 int sampling_ratio; 307 308 /* management/no-ack frames do not use rate control */ 309 if (rate_control_send_low(sta, priv_sta, txrc)) 310 return; 311 312 /* check multi-rate-retry capabilities & adjust lookaround_rate */ 313 mrr_capable = mp->has_mrr && 314 !txrc->rts && 315 !txrc->bss_conf->use_cts_prot; 316 if (mrr_capable) 317 sampling_ratio = mp->lookaround_rate_mrr; 318 else 319 sampling_ratio = mp->lookaround_rate; 320 321 /* increase sum packet counter */ 322 mi->total_packets++; 323 324#ifdef CONFIG_MAC80211_DEBUGFS 325 if (mp->fixed_rate_idx != -1) 326 return; 327#endif 328 329 delta = (mi->total_packets * sampling_ratio / 100) - 330 (mi->sample_packets + mi->sample_deferred / 2); 331 332 /* delta < 0: no sampling required */ 333 prev_sample = mi->prev_sample; 334 mi->prev_sample = false; 335 if (delta < 0 || (!mrr_capable && prev_sample)) 336 return; 337 338 if (mi->total_packets >= 10000) { 339 mi->sample_deferred = 0; 340 mi->sample_packets = 0; 341 mi->total_packets = 0; 342 } else if (delta > mi->n_rates * 2) { 343 /* With multi-rate retry, not every planned sample 344 * attempt actually gets used, due to the way the retry 345 * chain is set up - [max_tp,sample,prob,lowest] for 346 * sample_rate < max_tp. 347 * 348 * If there's too much sampling backlog and the link 349 * starts getting worse, minstrel would start bursting 350 * out lots of sampling frames, which would result 351 * in a large throughput loss. */ 352 mi->sample_packets += (delta - mi->n_rates * 2); 353 } 354 355 /* get next random rate sample */ 356 ndx = minstrel_get_next_sample(mi); 357 msr = &mi->r[ndx]; 358 mr = &mi->r[mi->max_tp_rate[0]]; 359 360 /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage) 361 * rate sampling method should be used. 362 * Respect such rates that are not sampled for 20 interations. 363 */ 364 if (mrr_capable && 365 msr->perfect_tx_time > mr->perfect_tx_time && 366 msr->stats.sample_skipped < 20) { 367 /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark 368 * packets that have the sampling rate deferred to the 369 * second MRR stage. Increase the sample counter only 370 * if the deferred sample rate was actually used. 371 * Use the sample_deferred counter to make sure that 372 * the sampling is not done in large bursts */ 373 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; 374 rate++; 375 mi->sample_deferred++; 376 } else { 377 if (!msr->sample_limit != 0) 378 return; 379 380 mi->sample_packets++; 381 if (msr->sample_limit > 0) 382 msr->sample_limit--; 383 } 384 385 /* If we're not using MRR and the sampling rate already 386 * has a probability of >95%, we shouldn't be attempting 387 * to use it, as this only wastes precious airtime */ 388 if (!mrr_capable && 389 (mi->r[ndx].stats.probability > MINSTREL_FRAC(95, 100))) 390 return; 391 392 mi->prev_sample = true; 393 394 rate->idx = mi->r[ndx].rix; 395 rate->count = minstrel_get_retry_count(&mi->r[ndx], info); 396} 397 398 399static void 400calc_rate_durations(enum ieee80211_band band, 401 struct minstrel_rate *d, 402 struct ieee80211_rate *rate, 403 struct cfg80211_chan_def *chandef) 404{ 405 int erp = !!(rate->flags & IEEE80211_RATE_ERP_G); 406 int shift = ieee80211_chandef_get_shift(chandef); 407 408 d->perfect_tx_time = ieee80211_frame_duration(band, 1200, 409 DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1, 410 shift); 411 d->ack_time = ieee80211_frame_duration(band, 10, 412 DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1, 413 shift); 414} 415 416static void 417init_sample_table(struct minstrel_sta_info *mi) 418{ 419 unsigned int i, col, new_idx; 420 u8 rnd[8]; 421 422 mi->sample_column = 0; 423 mi->sample_row = 0; 424 memset(mi->sample_table, 0xff, SAMPLE_COLUMNS * mi->n_rates); 425 426 for (col = 0; col < SAMPLE_COLUMNS; col++) { 427 prandom_bytes(rnd, sizeof(rnd)); 428 for (i = 0; i < mi->n_rates; i++) { 429 new_idx = (i + rnd[i & 7]) % mi->n_rates; 430 while (SAMPLE_TBL(mi, new_idx, col) != 0xff) 431 new_idx = (new_idx + 1) % mi->n_rates; 432 433 SAMPLE_TBL(mi, new_idx, col) = i; 434 } 435 } 436} 437 438static void 439minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, 440 struct cfg80211_chan_def *chandef, 441 struct ieee80211_sta *sta, void *priv_sta) 442{ 443 struct minstrel_sta_info *mi = priv_sta; 444 struct minstrel_priv *mp = priv; 445 struct ieee80211_rate *ctl_rate; 446 unsigned int i, n = 0; 447 unsigned int t_slot = 9; /* FIXME: get real slot time */ 448 u32 rate_flags; 449 450 mi->sta = sta; 451 mi->lowest_rix = rate_lowest_index(sband, sta); 452 ctl_rate = &sband->bitrates[mi->lowest_rix]; 453 mi->sp_ack_dur = ieee80211_frame_duration(sband->band, 10, 454 ctl_rate->bitrate, 455 !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1, 456 ieee80211_chandef_get_shift(chandef)); 457 458 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); 459 memset(mi->max_tp_rate, 0, sizeof(mi->max_tp_rate)); 460 mi->max_prob_rate = 0; 461 462 for (i = 0; i < sband->n_bitrates; i++) { 463 struct minstrel_rate *mr = &mi->r[n]; 464 struct minstrel_rate_stats *mrs = &mi->r[n].stats; 465 unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0; 466 unsigned int tx_time_single; 467 unsigned int cw = mp->cw_min; 468 int shift; 469 470 if (!rate_supported(sta, sband->band, i)) 471 continue; 472 if ((rate_flags & sband->bitrates[i].flags) != rate_flags) 473 continue; 474 475 n++; 476 memset(mr, 0, sizeof(*mr)); 477 memset(mrs, 0, sizeof(*mrs)); 478 479 mr->rix = i; 480 shift = ieee80211_chandef_get_shift(chandef); 481 mr->bitrate = DIV_ROUND_UP(sband->bitrates[i].bitrate, 482 (1 << shift) * 5); 483 calc_rate_durations(sband->band, mr, &sband->bitrates[i], 484 chandef); 485 486 /* calculate maximum number of retransmissions before 487 * fallback (based on maximum segment size) */ 488 mr->sample_limit = -1; 489 mrs->retry_count = 1; 490 mr->retry_count_cts = 1; 491 mrs->retry_count_rtscts = 1; 492 tx_time = mr->perfect_tx_time + mi->sp_ack_dur; 493 do { 494 /* add one retransmission */ 495 tx_time_single = mr->ack_time + mr->perfect_tx_time; 496 497 /* contention window */ 498 tx_time_single += (t_slot * cw) >> 1; 499 cw = min((cw << 1) | 1, mp->cw_max); 500 501 tx_time += tx_time_single; 502 tx_time_cts += tx_time_single + mi->sp_ack_dur; 503 tx_time_rtscts += tx_time_single + 2 * mi->sp_ack_dur; 504 if ((tx_time_cts < mp->segment_size) && 505 (mr->retry_count_cts < mp->max_retry)) 506 mr->retry_count_cts++; 507 if ((tx_time_rtscts < mp->segment_size) && 508 (mrs->retry_count_rtscts < mp->max_retry)) 509 mrs->retry_count_rtscts++; 510 } while ((tx_time < mp->segment_size) && 511 (++mr->stats.retry_count < mp->max_retry)); 512 mr->adjusted_retry_count = mrs->retry_count; 513 if (!(sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)) 514 mr->retry_count_cts = mrs->retry_count; 515 } 516 517 for (i = n; i < sband->n_bitrates; i++) { 518 struct minstrel_rate *mr = &mi->r[i]; 519 mr->rix = -1; 520 } 521 522 mi->n_rates = n; 523 mi->stats_update = jiffies; 524 525 init_sample_table(mi); 526 minstrel_update_rates(mp, mi); 527} 528 529static void * 530minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) 531{ 532 struct ieee80211_supported_band *sband; 533 struct minstrel_sta_info *mi; 534 struct minstrel_priv *mp = priv; 535 struct ieee80211_hw *hw = mp->hw; 536 int max_rates = 0; 537 int i; 538 539 mi = kzalloc(sizeof(struct minstrel_sta_info), gfp); 540 if (!mi) 541 return NULL; 542 543 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 544 sband = hw->wiphy->bands[i]; 545 if (sband && sband->n_bitrates > max_rates) 546 max_rates = sband->n_bitrates; 547 } 548 549 mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); 550 if (!mi->r) 551 goto error; 552 553 mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); 554 if (!mi->sample_table) 555 goto error1; 556 557 mi->stats_update = jiffies; 558 return mi; 559 560error1: 561 kfree(mi->r); 562error: 563 kfree(mi); 564 return NULL; 565} 566 567static void 568minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) 569{ 570 struct minstrel_sta_info *mi = priv_sta; 571 572 kfree(mi->sample_table); 573 kfree(mi->r); 574 kfree(mi); 575} 576 577static void 578minstrel_init_cck_rates(struct minstrel_priv *mp) 579{ 580 static const int bitrates[4] = { 10, 20, 55, 110 }; 581 struct ieee80211_supported_band *sband; 582 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); 583 int i, j; 584 585 sband = mp->hw->wiphy->bands[IEEE80211_BAND_2GHZ]; 586 if (!sband) 587 return; 588 589 for (i = 0, j = 0; i < sband->n_bitrates; i++) { 590 struct ieee80211_rate *rate = &sband->bitrates[i]; 591 592 if (rate->flags & IEEE80211_RATE_ERP_G) 593 continue; 594 595 if ((rate_flags & sband->bitrates[i].flags) != rate_flags) 596 continue; 597 598 for (j = 0; j < ARRAY_SIZE(bitrates); j++) { 599 if (rate->bitrate != bitrates[j]) 600 continue; 601 602 mp->cck_rates[j] = i; 603 break; 604 } 605 } 606} 607 608static void * 609minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) 610{ 611 struct minstrel_priv *mp; 612 613 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); 614 if (!mp) 615 return NULL; 616 617 /* contention window settings 618 * Just an approximation. Using the per-queue values would complicate 619 * the calculations and is probably unnecessary */ 620 mp->cw_min = 15; 621 mp->cw_max = 1023; 622 623 /* number of packets (in %) to use for sampling other rates 624 * sample less often for non-mrr packets, because the overhead 625 * is much higher than with mrr */ 626 mp->lookaround_rate = 5; 627 mp->lookaround_rate_mrr = 10; 628 629 /* maximum time that the hw is allowed to stay in one MRR segment */ 630 mp->segment_size = 6000; 631 632 if (hw->max_rate_tries > 0) 633 mp->max_retry = hw->max_rate_tries; 634 else 635 /* safe default, does not necessarily have to match hw properties */ 636 mp->max_retry = 7; 637 638 if (hw->max_rates >= 4) 639 mp->has_mrr = true; 640 641 mp->hw = hw; 642 mp->update_interval = 100; 643 644#ifdef CONFIG_MAC80211_DEBUGFS 645 mp->fixed_rate_idx = (u32) -1; 646 mp->dbg_fixed_rate = debugfs_create_u32("fixed_rate_idx", 647 S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx); 648#endif 649 650 minstrel_init_cck_rates(mp); 651 652 return mp; 653} 654 655static void 656minstrel_free(void *priv) 657{ 658#ifdef CONFIG_MAC80211_DEBUGFS 659 debugfs_remove(((struct minstrel_priv *)priv)->dbg_fixed_rate); 660#endif 661 kfree(priv); 662} 663 664static u32 minstrel_get_expected_throughput(void *priv_sta) 665{ 666 struct minstrel_sta_info *mi = priv_sta; 667 int idx = mi->max_tp_rate[0]; 668 669 /* convert pkt per sec in kbps (1200 is the average pkt size used for 670 * computing cur_tp 671 */ 672 return MINSTREL_TRUNC(mi->r[idx].stats.cur_tp) * 1200 * 8 / 1024; 673} 674 675const struct rate_control_ops mac80211_minstrel = { 676 .name = "minstrel", 677 .tx_status = minstrel_tx_status, 678 .get_rate = minstrel_get_rate, 679 .rate_init = minstrel_rate_init, 680 .alloc = minstrel_alloc, 681 .free = minstrel_free, 682 .alloc_sta = minstrel_alloc_sta, 683 .free_sta = minstrel_free_sta, 684#ifdef CONFIG_MAC80211_DEBUGFS 685 .add_sta_debugfs = minstrel_add_sta_debugfs, 686 .remove_sta_debugfs = minstrel_remove_sta_debugfs, 687#endif 688 .get_expected_throughput = minstrel_get_expected_throughput, 689}; 690 691int __init 692rc80211_minstrel_init(void) 693{ 694 return ieee80211_rate_control_register(&mac80211_minstrel); 695} 696 697void 698rc80211_minstrel_exit(void) 699{ 700 ieee80211_rate_control_unregister(&mac80211_minstrel); 701} 702 703