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 */
62 static inline int
rix_to_ndx(struct minstrel_sta_info * mi,int rix)63 rix_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 */
73 static inline void
minstrel_sort_best_tp_rates(struct minstrel_sta_info * mi,int i,u8 * tp_list)74 minstrel_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].cur_tp > mi->r[tp_list[j - 1]].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
86 static void
minstrel_set_rate(struct minstrel_sta_info * mi,struct ieee80211_sta_rates * ratetbl,int offset,int idx)87 minstrel_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->retry_count_rtscts;
96 }
97
98 static void
minstrel_update_rates(struct minstrel_priv * mp,struct minstrel_sta_info * mi)99 minstrel_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
130 static void
minstrel_update_stats(struct minstrel_priv * mp,struct minstrel_sta_info * mi)131 minstrel_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
144 usecs = mr->perfect_tx_time;
145 if (!usecs)
146 usecs = 1000000;
147
148 if (unlikely(mr->attempts > 0)) {
149 mr->sample_skipped = 0;
150 mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
151 mr->succ_hist += mr->success;
152 mr->att_hist += mr->attempts;
153 mr->probability = minstrel_ewma(mr->probability,
154 mr->cur_prob,
155 EWMA_LEVEL);
156 } else
157 mr->sample_skipped++;
158
159 mr->last_success = mr->success;
160 mr->last_attempts = mr->attempts;
161 mr->success = 0;
162 mr->attempts = 0;
163
164 /* Update throughput per rate, reset thr. below 10% success */
165 if (mr->probability < MINSTREL_FRAC(10, 100))
166 mr->cur_tp = 0;
167 else
168 mr->cur_tp = mr->probability * (1000000 / usecs);
169
170 /* Sample less often below the 10% chance of success.
171 * Sample less often above the 95% chance of success. */
172 if (mr->probability > MINSTREL_FRAC(95, 100) ||
173 mr->probability < MINSTREL_FRAC(10, 100)) {
174 mr->adjusted_retry_count = mr->retry_count >> 1;
175 if (mr->adjusted_retry_count > 2)
176 mr->adjusted_retry_count = 2;
177 mr->sample_limit = 4;
178 } else {
179 mr->sample_limit = -1;
180 mr->adjusted_retry_count = mr->retry_count;
181 }
182 if (!mr->adjusted_retry_count)
183 mr->adjusted_retry_count = 2;
184
185 minstrel_sort_best_tp_rates(mi, i, tmp_tp_rate);
186
187 /* To determine the most robust rate (max_prob_rate) used at
188 * 3rd mmr stage we distinct between two cases:
189 * (1) if any success probabilitiy >= 95%, out of those rates
190 * choose the maximum throughput rate as max_prob_rate
191 * (2) if all success probabilities < 95%, the rate with
192 * highest success probability is choosen as max_prob_rate */
193 if (mr->probability >= MINSTREL_FRAC(95,100)) {
194 if (mr->cur_tp >= mi->r[tmp_prob_rate].cur_tp)
195 tmp_prob_rate = i;
196 } else {
197 if (mr->probability >= mi->r[tmp_prob_rate].probability)
198 tmp_prob_rate = i;
199 }
200 }
201
202 /* Assign the new rate set */
203 memcpy(mi->max_tp_rate, tmp_tp_rate, sizeof(mi->max_tp_rate));
204 mi->max_prob_rate = tmp_prob_rate;
205
206 /* Reset update timer */
207 mi->stats_update = jiffies;
208
209 minstrel_update_rates(mp, mi);
210 }
211
212 static void
minstrel_tx_status(void * priv,struct ieee80211_supported_band * sband,struct ieee80211_sta * sta,void * priv_sta,struct sk_buff * skb)213 minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband,
214 struct ieee80211_sta *sta, void *priv_sta,
215 struct sk_buff *skb)
216 {
217 struct minstrel_priv *mp = priv;
218 struct minstrel_sta_info *mi = priv_sta;
219 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
220 struct ieee80211_tx_rate *ar = info->status.rates;
221 int i, ndx;
222 int success;
223
224 success = !!(info->flags & IEEE80211_TX_STAT_ACK);
225
226 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
227 if (ar[i].idx < 0)
228 break;
229
230 ndx = rix_to_ndx(mi, ar[i].idx);
231 if (ndx < 0)
232 continue;
233
234 mi->r[ndx].attempts += ar[i].count;
235
236 if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0))
237 mi->r[ndx].success += success;
238 }
239
240 if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0))
241 mi->sample_count++;
242
243 if (mi->sample_deferred > 0)
244 mi->sample_deferred--;
245
246 if (time_after(jiffies, mi->stats_update +
247 (mp->update_interval * HZ) / 1000))
248 minstrel_update_stats(mp, mi);
249 }
250
251
252 static inline unsigned int
minstrel_get_retry_count(struct minstrel_rate * mr,struct ieee80211_tx_info * info)253 minstrel_get_retry_count(struct minstrel_rate *mr,
254 struct ieee80211_tx_info *info)
255 {
256 unsigned int retry = mr->adjusted_retry_count;
257
258 if (info->control.use_rts)
259 retry = max(2U, min(mr->retry_count_rtscts, retry));
260 else if (info->control.use_cts_prot)
261 retry = max(2U, min(mr->retry_count_cts, retry));
262 return retry;
263 }
264
265
266 static int
minstrel_get_next_sample(struct minstrel_sta_info * mi)267 minstrel_get_next_sample(struct minstrel_sta_info *mi)
268 {
269 unsigned int sample_ndx;
270 sample_ndx = SAMPLE_TBL(mi, mi->sample_row, mi->sample_column);
271 mi->sample_row++;
272 if ((int) mi->sample_row >= mi->n_rates) {
273 mi->sample_row = 0;
274 mi->sample_column++;
275 if (mi->sample_column >= SAMPLE_COLUMNS)
276 mi->sample_column = 0;
277 }
278 return sample_ndx;
279 }
280
281 static void
minstrel_get_rate(void * priv,struct ieee80211_sta * sta,void * priv_sta,struct ieee80211_tx_rate_control * txrc)282 minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
283 void *priv_sta, struct ieee80211_tx_rate_control *txrc)
284 {
285 struct sk_buff *skb = txrc->skb;
286 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
287 struct minstrel_sta_info *mi = priv_sta;
288 struct minstrel_priv *mp = priv;
289 struct ieee80211_tx_rate *rate = &info->control.rates[0];
290 struct minstrel_rate *msr, *mr;
291 unsigned int ndx;
292 bool mrr_capable;
293 bool prev_sample = mi->prev_sample;
294 int delta;
295 int sampling_ratio;
296
297 /* management/no-ack frames do not use rate control */
298 if (rate_control_send_low(sta, priv_sta, txrc))
299 return;
300
301 /* check multi-rate-retry capabilities & adjust lookaround_rate */
302 mrr_capable = mp->has_mrr &&
303 !txrc->rts &&
304 !txrc->bss_conf->use_cts_prot;
305 if (mrr_capable)
306 sampling_ratio = mp->lookaround_rate_mrr;
307 else
308 sampling_ratio = mp->lookaround_rate;
309
310 /* increase sum packet counter */
311 mi->packet_count++;
312
313 delta = (mi->packet_count * sampling_ratio / 100) -
314 (mi->sample_count + mi->sample_deferred / 2);
315
316 /* delta < 0: no sampling required */
317 mi->prev_sample = false;
318 if (delta < 0 || (!mrr_capable && prev_sample))
319 return;
320
321 if (mi->packet_count >= 10000) {
322 mi->sample_deferred = 0;
323 mi->sample_count = 0;
324 mi->packet_count = 0;
325 } else if (delta > mi->n_rates * 2) {
326 /* With multi-rate retry, not every planned sample
327 * attempt actually gets used, due to the way the retry
328 * chain is set up - [max_tp,sample,prob,lowest] for
329 * sample_rate < max_tp.
330 *
331 * If there's too much sampling backlog and the link
332 * starts getting worse, minstrel would start bursting
333 * out lots of sampling frames, which would result
334 * in a large throughput loss. */
335 mi->sample_count += (delta - mi->n_rates * 2);
336 }
337
338 /* get next random rate sample */
339 ndx = minstrel_get_next_sample(mi);
340 msr = &mi->r[ndx];
341 mr = &mi->r[mi->max_tp_rate[0]];
342
343 /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage)
344 * rate sampling method should be used.
345 * Respect such rates that are not sampled for 20 interations.
346 */
347 if (mrr_capable &&
348 msr->perfect_tx_time > mr->perfect_tx_time &&
349 msr->sample_skipped < 20) {
350 /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark
351 * packets that have the sampling rate deferred to the
352 * second MRR stage. Increase the sample counter only
353 * if the deferred sample rate was actually used.
354 * Use the sample_deferred counter to make sure that
355 * the sampling is not done in large bursts */
356 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
357 rate++;
358 mi->sample_deferred++;
359 } else {
360 if (!msr->sample_limit != 0)
361 return;
362
363 mi->sample_count++;
364 if (msr->sample_limit > 0)
365 msr->sample_limit--;
366 }
367
368 /* If we're not using MRR and the sampling rate already
369 * has a probability of >95%, we shouldn't be attempting
370 * to use it, as this only wastes precious airtime */
371 if (!mrr_capable &&
372 (mi->r[ndx].probability > MINSTREL_FRAC(95, 100)))
373 return;
374
375 mi->prev_sample = true;
376
377 rate->idx = mi->r[ndx].rix;
378 rate->count = minstrel_get_retry_count(&mi->r[ndx], info);
379 }
380
381
382 static void
calc_rate_durations(enum ieee80211_band band,struct minstrel_rate * d,struct ieee80211_rate * rate)383 calc_rate_durations(enum ieee80211_band band,
384 struct minstrel_rate *d,
385 struct ieee80211_rate *rate)
386 {
387 int erp = !!(rate->flags & IEEE80211_RATE_ERP_G);
388
389 d->perfect_tx_time = ieee80211_frame_duration(band, 1200,
390 rate->bitrate, erp, 1);
391 d->ack_time = ieee80211_frame_duration(band, 10,
392 rate->bitrate, erp, 1);
393 }
394
395 static void
init_sample_table(struct minstrel_sta_info * mi)396 init_sample_table(struct minstrel_sta_info *mi)
397 {
398 unsigned int i, col, new_idx;
399 u8 rnd[8];
400
401 mi->sample_column = 0;
402 mi->sample_row = 0;
403 memset(mi->sample_table, 0xff, SAMPLE_COLUMNS * mi->n_rates);
404
405 for (col = 0; col < SAMPLE_COLUMNS; col++) {
406 for (i = 0; i < mi->n_rates; i++) {
407 get_random_bytes(rnd, sizeof(rnd));
408 new_idx = (i + rnd[i & 7]) % mi->n_rates;
409
410 while (SAMPLE_TBL(mi, new_idx, col) != 0xff)
411 new_idx = (new_idx + 1) % mi->n_rates;
412
413 SAMPLE_TBL(mi, new_idx, col) = i;
414 }
415 }
416 }
417
418 static void
minstrel_rate_init(void * priv,struct ieee80211_supported_band * sband,struct ieee80211_sta * sta,void * priv_sta)419 minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
420 struct ieee80211_sta *sta, void *priv_sta)
421 {
422 struct minstrel_sta_info *mi = priv_sta;
423 struct minstrel_priv *mp = priv;
424 struct ieee80211_rate *ctl_rate;
425 unsigned int i, n = 0;
426 unsigned int t_slot = 9; /* FIXME: get real slot time */
427
428 mi->sta = sta;
429 mi->lowest_rix = rate_lowest_index(sband, sta);
430 ctl_rate = &sband->bitrates[mi->lowest_rix];
431 mi->sp_ack_dur = ieee80211_frame_duration(sband->band, 10,
432 ctl_rate->bitrate,
433 !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1);
434
435 memset(mi->max_tp_rate, 0, sizeof(mi->max_tp_rate));
436 mi->max_prob_rate = 0;
437
438 for (i = 0; i < sband->n_bitrates; i++) {
439 struct minstrel_rate *mr = &mi->r[n];
440 unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0;
441 unsigned int tx_time_single;
442 unsigned int cw = mp->cw_min;
443
444 if (!rate_supported(sta, sband->band, i))
445 continue;
446 n++;
447 memset(mr, 0, sizeof(*mr));
448
449 mr->rix = i;
450 mr->bitrate = sband->bitrates[i].bitrate / 5;
451 calc_rate_durations(sband->band, mr, &sband->bitrates[i]);
452
453 /* calculate maximum number of retransmissions before
454 * fallback (based on maximum segment size) */
455 mr->sample_limit = -1;
456 mr->retry_count = 1;
457 mr->retry_count_cts = 1;
458 mr->retry_count_rtscts = 1;
459 tx_time = mr->perfect_tx_time + mi->sp_ack_dur;
460 do {
461 /* add one retransmission */
462 tx_time_single = mr->ack_time + mr->perfect_tx_time;
463
464 /* contention window */
465 tx_time_single += (t_slot * cw) >> 1;
466 cw = min((cw << 1) | 1, mp->cw_max);
467
468 tx_time += tx_time_single;
469 tx_time_cts += tx_time_single + mi->sp_ack_dur;
470 tx_time_rtscts += tx_time_single + 2 * mi->sp_ack_dur;
471 if ((tx_time_cts < mp->segment_size) &&
472 (mr->retry_count_cts < mp->max_retry))
473 mr->retry_count_cts++;
474 if ((tx_time_rtscts < mp->segment_size) &&
475 (mr->retry_count_rtscts < mp->max_retry))
476 mr->retry_count_rtscts++;
477 } while ((tx_time < mp->segment_size) &&
478 (++mr->retry_count < mp->max_retry));
479 mr->adjusted_retry_count = mr->retry_count;
480 if (!(sband->bitrates[i].flags & IEEE80211_RATE_ERP_G))
481 mr->retry_count_cts = mr->retry_count;
482 }
483
484 for (i = n; i < sband->n_bitrates; i++) {
485 struct minstrel_rate *mr = &mi->r[i];
486 mr->rix = -1;
487 }
488
489 mi->n_rates = n;
490 mi->stats_update = jiffies;
491
492 init_sample_table(mi);
493 minstrel_update_rates(mp, mi);
494 }
495
496 static void *
minstrel_alloc_sta(void * priv,struct ieee80211_sta * sta,gfp_t gfp)497 minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
498 {
499 struct ieee80211_supported_band *sband;
500 struct minstrel_sta_info *mi;
501 struct minstrel_priv *mp = priv;
502 struct ieee80211_hw *hw = mp->hw;
503 int max_rates = 0;
504 int i;
505
506 mi = kzalloc(sizeof(struct minstrel_sta_info), gfp);
507 if (!mi)
508 return NULL;
509
510 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
511 sband = hw->wiphy->bands[i];
512 if (sband && sband->n_bitrates > max_rates)
513 max_rates = sband->n_bitrates;
514 }
515
516 mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
517 if (!mi->r)
518 goto error;
519
520 mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
521 if (!mi->sample_table)
522 goto error1;
523
524 mi->stats_update = jiffies;
525 return mi;
526
527 error1:
528 kfree(mi->r);
529 error:
530 kfree(mi);
531 return NULL;
532 }
533
534 static void
minstrel_free_sta(void * priv,struct ieee80211_sta * sta,void * priv_sta)535 minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
536 {
537 struct minstrel_sta_info *mi = priv_sta;
538
539 kfree(mi->sample_table);
540 kfree(mi->r);
541 kfree(mi);
542 }
543
544 static void
minstrel_init_cck_rates(struct minstrel_priv * mp)545 minstrel_init_cck_rates(struct minstrel_priv *mp)
546 {
547 static const int bitrates[4] = { 10, 20, 55, 110 };
548 struct ieee80211_supported_band *sband;
549 int i, j;
550
551 sband = mp->hw->wiphy->bands[IEEE80211_BAND_2GHZ];
552 if (!sband)
553 return;
554
555 for (i = 0, j = 0; i < sband->n_bitrates; i++) {
556 struct ieee80211_rate *rate = &sband->bitrates[i];
557
558 if (rate->flags & IEEE80211_RATE_ERP_G)
559 continue;
560
561 for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
562 if (rate->bitrate != bitrates[j])
563 continue;
564
565 mp->cck_rates[j] = i;
566 break;
567 }
568 }
569 }
570
571 static void *
minstrel_alloc(struct ieee80211_hw * hw,struct dentry * debugfsdir)572 minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
573 {
574 struct minstrel_priv *mp;
575
576 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
577 if (!mp)
578 return NULL;
579
580 /* contention window settings
581 * Just an approximation. Using the per-queue values would complicate
582 * the calculations and is probably unnecessary */
583 mp->cw_min = 15;
584 mp->cw_max = 1023;
585
586 /* number of packets (in %) to use for sampling other rates
587 * sample less often for non-mrr packets, because the overhead
588 * is much higher than with mrr */
589 mp->lookaround_rate = 5;
590 mp->lookaround_rate_mrr = 10;
591
592 /* maximum time that the hw is allowed to stay in one MRR segment */
593 mp->segment_size = 6000;
594
595 if (hw->max_rate_tries > 0)
596 mp->max_retry = hw->max_rate_tries;
597 else
598 /* safe default, does not necessarily have to match hw properties */
599 mp->max_retry = 7;
600
601 if (hw->max_rates >= 4)
602 mp->has_mrr = true;
603
604 mp->hw = hw;
605 mp->update_interval = 100;
606
607 #ifdef CONFIG_MAC80211_DEBUGFS
608 mp->fixed_rate_idx = (u32) -1;
609 mp->dbg_fixed_rate = debugfs_create_u32("fixed_rate_idx",
610 S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx);
611 #endif
612
613 minstrel_init_cck_rates(mp);
614
615 return mp;
616 }
617
618 static void
minstrel_free(void * priv)619 minstrel_free(void *priv)
620 {
621 #ifdef CONFIG_MAC80211_DEBUGFS
622 debugfs_remove(((struct minstrel_priv *)priv)->dbg_fixed_rate);
623 #endif
624 kfree(priv);
625 }
626
627 struct rate_control_ops mac80211_minstrel = {
628 .name = "minstrel",
629 .tx_status = minstrel_tx_status,
630 .get_rate = minstrel_get_rate,
631 .rate_init = minstrel_rate_init,
632 .alloc = minstrel_alloc,
633 .free = minstrel_free,
634 .alloc_sta = minstrel_alloc_sta,
635 .free_sta = minstrel_free_sta,
636 #ifdef CONFIG_MAC80211_DEBUGFS
637 .add_sta_debugfs = minstrel_add_sta_debugfs,
638 .remove_sta_debugfs = minstrel_remove_sta_debugfs,
639 #endif
640 };
641
642 int __init
rc80211_minstrel_init(void)643 rc80211_minstrel_init(void)
644 {
645 return ieee80211_rate_control_register(&mac80211_minstrel);
646 }
647
648 void
rc80211_minstrel_exit(void)649 rc80211_minstrel_exit(void)
650 {
651 ieee80211_rate_control_unregister(&mac80211_minstrel);
652 }
653
654