drivers/net/wireless/iwlwifi/iwl-3945-rs.c

   1 /******************************************************************************
   2  *
   3  * Copyright(c) 2005 - 2008 Intel Corporation. All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
  17  *
  18  * The full GNU General Public License is included in this distribution in the
  19  * file called LICENSE.
  20  *
  21  * Contact Information:
  22  * James P. Ketrenos <ipw2100-admin@linux.intel.com>
  23  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  24  *
  25  *****************************************************************************/
  26
  27 #include <linux/kernel.h>
  28 #include <linux/init.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/wireless.h>
  31 #include <net/mac80211.h>
  32
  33 #include <linux/netdevice.h>
  34 #include <linux/etherdevice.h>
  35 #include <linux/delay.h>
  36
  37 #include <linux/workqueue.h>
  38
  39 #include "iwl-3945.h"
  40
  41 #define RS_NAME "iwl-3945-rs"
  42
  43 struct iwl3945_rate_scale_data {
  44         u64 data;
  45         s32 success_counter;
  46         s32 success_ratio;
  47         s32 counter;
  48         s32 average_tpt;
  49         unsigned long stamp;
  50 };
  51
  52 struct iwl3945_rs_sta {
  53         spinlock_t lock;
  54         s32 *expected_tpt;
  55         unsigned long last_partial_flush;
  56         unsigned long last_flush;
  57         u32 flush_time;
  58         u32 last_tx_packets;
  59         u32 tx_packets;
  60         u8 tgg;
  61         u8 flush_pending;
  62         u8 start_rate;
  63         u8 ibss_sta_added;
  64         struct timer_list rate_scale_flush;
  65         struct iwl3945_rate_scale_data win[IWL_RATE_COUNT];
  66
  67         /* used to be in sta_info */
  68         int last_txrate_idx;
  69 };
  70
  71 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT] = {
  72         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  73 };
  74
  75 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT] = {
  76         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  77 };
  78
  79 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT] = {
  80         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  81 };
  82
  83 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT] = {
  84         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  85 };
  86
  87 struct iwl3945_tpt_entry {
  88         s8 min_rssi;
  89         u8 index;
  90 };
  91
  92 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
  93         {-60, IWL_RATE_54M_INDEX},
  94         {-64, IWL_RATE_48M_INDEX},
  95         {-72, IWL_RATE_36M_INDEX},
  96         {-80, IWL_RATE_24M_INDEX},
  97         {-84, IWL_RATE_18M_INDEX},
  98         {-85, IWL_RATE_12M_INDEX},
  99         {-87, IWL_RATE_9M_INDEX},
 100         {-89, IWL_RATE_6M_INDEX}
 101 };
 102
 103 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
 104         {-60, IWL_RATE_54M_INDEX},
 105         {-64, IWL_RATE_48M_INDEX},
 106         {-68, IWL_RATE_36M_INDEX},
 107         {-80, IWL_RATE_24M_INDEX},
 108         {-84, IWL_RATE_18M_INDEX},
 109         {-85, IWL_RATE_12M_INDEX},
 110         {-86, IWL_RATE_11M_INDEX},
 111         {-88, IWL_RATE_5M_INDEX},
 112         {-90, IWL_RATE_2M_INDEX},
 113         {-92, IWL_RATE_1M_INDEX}
 114 };
 115
 116 #define IWL_RATE_MAX_WINDOW          62
 117 #define IWL_RATE_FLUSH        (3*HZ/10)
 118 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 119 #define IWL_RATE_HIGH_TH          11520
 120 #define IWL_RATE_MIN_FAILURE_TH       8
 121 #define IWL_RATE_MIN_SUCCESS_TH       8
 122 #define IWL_RATE_DECREASE_TH       1920
 123
 124 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 125 {
 126         u32 index = 0;
 127         u32 table_size = 0;
 128         struct iwl3945_tpt_entry *tpt_table = NULL;
 129
 130         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 131                 rssi = IWL_MIN_RSSI_VAL;
 132
 133         switch (band) {
 134         case IEEE80211_BAND_2GHZ:
 135                 tpt_table = iwl3945_tpt_table_g;
 136                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 137                 break;
 138
 139         case IEEE80211_BAND_5GHZ:
 140                 tpt_table = iwl3945_tpt_table_a;
 141                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 142                 break;
 143
 144         default:
 145                 BUG();
 146                 break;
 147         }
 148
 149         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 150                 index++;
 151
 152         index = min(index, (table_size - 1));
 153
 154         return tpt_table[index].index;
 155 }
 156
 157 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 158 {
 159         window->data = 0;
 160         window->success_counter = 0;
 161         window->success_ratio = -1;
 162         window->counter = 0;
 163         window->average_tpt = IWL_INV_TPT;
 164         window->stamp = 0;
 165 }
 166
 167 /**
 168  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 169  *
 170  * Returns the number of windows that have gathered data but were
 171  * not flushed.  If there were any that were not flushed, then
 172  * reschedule the rate flushing routine.
 173  */
 174 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 175 {
 176         int unflushed = 0;
 177         int i;
 178         unsigned long flags;
 179
 180         /*
 181          * For each rate, if we have collected data on that rate
 182          * and it has been more than IWL_RATE_WIN_FLUSH
 183          * since we flushed, clear out the gathered statistics
 184          */
 185         for (i = 0; i < IWL_RATE_COUNT; i++) {
 186                 if (!rs_sta->win[i].counter)
 187                         continue;
 188
 189                 spin_lock_irqsave(&rs_sta->lock, flags);
 190                 if (time_after(jiffies, rs_sta->win[i].stamp +
 191                                IWL_RATE_WIN_FLUSH)) {
 192                         IWL_DEBUG_RATE("flushing %d samples of rate "
 193                                        "index %d\n",
 194                                        rs_sta->win[i].counter, i);
 195                         iwl3945_clear_window(&rs_sta->win[i]);
 196                 } else
 197                         unflushed++;
 198                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 199         }
 200
 201         return unflushed;
 202 }
 203
 204 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 205 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 206
 207 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 208 {
 209         struct iwl3945_rs_sta *rs_sta = (void *)data;
 210         int unflushed = 0;
 211         unsigned long flags;
 212         u32 packet_count, duration, pps;
 213
 214         IWL_DEBUG_RATE("enter\n");
 215
 216         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 217
 218         spin_lock_irqsave(&rs_sta->lock, flags);
 219
 220         rs_sta->flush_pending = 0;
 221
 222         /* Number of packets Rx'd since last time this timer ran */
 223         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 224
 225         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 226
 227         if (unflushed) {
 228                 duration =
 229                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 230 /*              duration = jiffies_to_msecs(rs_sta->flush_time); */
 231
 232                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 233                                packet_count, duration);
 234
 235                 /* Determine packets per second */
 236                 if (duration)
 237                         pps = (packet_count * 1000) / duration;
 238                 else
 239                         pps = 0;
 240
 241                 if (pps) {
 242                         duration = IWL_RATE_FLUSH_MAX / pps;
 243                         if (duration < IWL_RATE_FLUSH_MIN)
 244                                 duration = IWL_RATE_FLUSH_MIN;
 245                 } else
 246                         duration = IWL_RATE_FLUSH_MAX;
 247
 248                 rs_sta->flush_time = msecs_to_jiffies(duration);
 249
 250                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 251                                duration, packet_count);
 252
 253                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 254                           rs_sta->flush_time);
 255
 256                 rs_sta->last_partial_flush = jiffies;
 257         }
 258
 259         /* If there weren't any unflushed entries, we don't schedule the timer
 260          * to run again */
 261
 262         rs_sta->last_flush = jiffies;
 263
 264         spin_unlock_irqrestore(&rs_sta->lock, flags);
 265
 266         IWL_DEBUG_RATE("leave\n");
 267 }
 268
 269 /**
 270  * iwl3945_collect_tx_data - Update the success/failure sliding window
 271  *
 272  * We keep a sliding window of the last 64 packets transmitted
 273  * at this rate.  window->data contains the bitmask of successful
 274  * packets.
 275  */
 276 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 277                                 struct iwl3945_rate_scale_data *window,
 278                                 int success, int retries)
 279 {
 280         unsigned long flags;
 281
 282         if (!retries) {
 283                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 284                 return;
 285         }
 286
 287         while (retries--) {
 288                 spin_lock_irqsave(&rs_sta->lock, flags);
 289
 290                 /* If we have filled up the window then subtract one from the
 291                  * success counter if the high-bit is counting toward
 292                  * success */
 293                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 294                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 295                                 window->success_counter--;
 296                 } else
 297                         window->counter++;
 298
 299                 /* Slide the window to the left one bit */
 300                 window->data = (window->data << 1);
 301
 302                 /* If this packet was a success then set the low bit high */
 303                 if (success) {
 304                         window->success_counter++;
 305                         window->data |= 1;
 306                 }
 307
 308                 /* window->counter can't be 0 -- it is either >0 or
 309                  * IWL_RATE_MAX_WINDOW */
 310                 window->success_ratio = 12800 * window->success_counter /
 311                     window->counter;
 312
 313                 /* Tag this window as having been updated */
 314                 window->stamp = jiffies;
 315
 316                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 317         }
 318 }
 319
 320 static void rs_rate_init(void *priv, struct ieee80211_supported_band *sband,
 321                          struct ieee80211_sta *sta, void *priv_sta)
 322 {
 323         struct iwl3945_rs_sta *rs_sta = priv_sta;
 324         int i;
 325
 326         IWL_DEBUG_RATE("enter\n");
 327
 328         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 329          * the lowest or the highest rate.. Could consider using RSSI from
 330          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 331          * after assoc.. */
 332
 333         for (i = IWL_RATE_COUNT - 1; i >= 0; i--) {
 334                 if (sta->supp_rates[sband->band] & (1 << i)) {
 335                         rs_sta->last_txrate_idx = i;
 336                         break;
 337                 }
 338         }
 339
 340         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 341         if (sband->band == IEEE80211_BAND_5GHZ)
 342                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 343
 344         IWL_DEBUG_RATE("leave\n");
 345 }
 346
 347 static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 348 {
 349         return hw->priv;
 350 }
 351
 352 /* rate scale requires free function to be implemented */
 353 static void rs_free(void *priv)
 354 {
 355         return;
 356 }
 357
 358 static void *rs_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 359 {
 360         struct iwl3945_rs_sta *rs_sta;
 361         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 362         int i;
 363
 364         /*
 365          * XXX: If it's using sta->drv_priv anyway, it might
 366          *      as well just put all the information there.
 367          */
 368
 369         IWL_DEBUG_RATE("enter\n");
 370
 371         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 372         if (!rs_sta) {
 373                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 374                 return NULL;
 375         }
 376
 377         psta->rs_sta = rs_sta;
 378
 379         spin_lock_init(&rs_sta->lock);
 380
 381         rs_sta->start_rate = IWL_RATE_INVALID;
 382
 383         /* default to just 802.11b */
 384         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 385
 386         rs_sta->last_partial_flush = jiffies;
 387         rs_sta->last_flush = jiffies;
 388         rs_sta->flush_time = IWL_RATE_FLUSH;
 389         rs_sta->last_tx_packets = 0;
 390         rs_sta->ibss_sta_added = 0;
 391
 392         init_timer(&rs_sta->rate_scale_flush);
 393         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 394         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 395
 396         for (i = 0; i < IWL_RATE_COUNT; i++)
 397                 iwl3945_clear_window(&rs_sta->win[i]);
 398
 399         IWL_DEBUG_RATE("leave\n");
 400
 401         return rs_sta;
 402 }
 403
 404 static void rs_free_sta(void *priv, struct ieee80211_sta *sta,
 405                         void *priv_sta)
 406 {
 407         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 408         struct iwl3945_rs_sta *rs_sta = priv_sta;
 409
 410         psta->rs_sta = NULL;
 411
 412         IWL_DEBUG_RATE("enter\n");
 413         del_timer_sync(&rs_sta->rate_scale_flush);
 414         kfree(rs_sta);
 415         IWL_DEBUG_RATE("leave\n");
 416 }
 417
 418
 419 /**
 420  * rs_tx_status - Update rate control values based on Tx results
 421  *
 422  * NOTE: Uses iwl3945_priv->retry_rate for the # of retries attempted by
 423  * the hardware for each rate.
 424  */
 425 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 426                          struct ieee80211_sta *sta, void *priv_sta,
 427                          struct sk_buff *skb)
 428 {
 429         u8 retries = 0, current_count;
 430         int scale_rate_index, first_index, last_index;
 431         unsigned long flags;
 432         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 433         struct iwl3945_rs_sta *rs_sta = priv_sta;
 434         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 435         int i;
 436
 437         IWL_DEBUG_RATE("enter\n");
 438
 439         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++)
 440                 retries += info->status.rates[i].count;
 441         retries--;
 442
 443         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
 444         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 445                 IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);
 446                 return;
 447         }
 448
 449         if (!priv_sta) {
 450                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 451                 return;
 452         }
 453
 454         rs_sta->tx_packets++;
 455
 456         scale_rate_index = first_index;
 457         last_index = first_index;
 458
 459         /*
 460          * Update the window for each rate.  We determine which rates
 461          * were Tx'd based on the total number of retries vs. the number
 462          * of retries configured for each rate -- currently set to the
 463          * priv value 'retry_rate' vs. rate specific
 464          *
 465          * On exit from this while loop last_index indicates the rate
 466          * at which the frame was finally transmitted (or failed if no
 467          * ACK)
 468          */
 469         while (retries > 0) {
 470                 if (retries < priv->retry_rate) {
 471                         current_count = retries;
 472                         last_index = scale_rate_index;
 473                 } else {
 474                         current_count = priv->retry_rate;
 475                         last_index = iwl3945_rs_next_rate(priv,
 476                                                          scale_rate_index);
 477                 }
 478
 479                 /* Update this rate accounting for as many retries
 480                  * as was used for it (per current_count) */
 481                 iwl3945_collect_tx_data(rs_sta,
 482                                     &rs_sta->win[scale_rate_index],
 483                                     0, current_count);
 484                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 485                                scale_rate_index, current_count);
 486
 487                 retries -= current_count;
 488
 489                 if (retries)
 490                         scale_rate_index =
 491                             iwl3945_rs_next_rate(priv, scale_rate_index);
 492         }
 493
 494
 495         /* Update the last index window with success/failure based on ACK */
 496         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 497                        last_index,
 498                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 499                        "success" : "failure");
 500         iwl3945_collect_tx_data(rs_sta,
 501                             &rs_sta->win[last_index],
 502                             info->flags & IEEE80211_TX_STAT_ACK, 1);
 503
 504         /* We updated the rate scale window -- if its been more than
 505          * flush_time since the last run, schedule the flush
 506          * again */
 507         spin_lock_irqsave(&rs_sta->lock, flags);
 508
 509         if (!rs_sta->flush_pending &&
 510             time_after(jiffies, rs_sta->last_partial_flush +
 511                        rs_sta->flush_time)) {
 512
 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         IWL_DEBUG_RATE("leave\n");
 521
 522         return;
 523 }
 524
 525 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 526                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 527 {
 528         u8 high = IWL_RATE_INVALID;
 529         u8 low = IWL_RATE_INVALID;
 530
 531         /* 802.11A walks to the next literal adjacent rate in
 532          * the rate table */
 533         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 534                 int i;
 535                 u32 mask;
 536
 537                 /* Find the previous rate that is in the rate mask */
 538                 i = index - 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 = index + 1;
 548                 for (mask = (1 << i); i < IWL_RATE_COUNT; 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 = index;
 559         while (low != IWL_RATE_INVALID) {
 560                 if (rs_sta->tgg)
 561                         low = iwl3945_rates[low].prev_rs_tgg;
 562                 else
 563                         low = iwl3945_rates[low].prev_rs;
 564                 if (low == IWL_RATE_INVALID)
 565                         break;
 566                 if (rate_mask & (1 << low))
 567                         break;
 568                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 569         }
 570
 571         high = index;
 572         while (high != IWL_RATE_INVALID) {
 573                 if (rs_sta->tgg)
 574                         high = iwl3945_rates[high].next_rs_tgg;
 575                 else
 576                         high = iwl3945_rates[high].next_rs;
 577                 if (high == IWL_RATE_INVALID)
 578                         break;
 579                 if (rate_mask & (1 << high))
 580                         break;
 581                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 582         }
 583
 584         return (high << 8) | low;
 585 }
 586
 587 /**
 588  * rs_get_rate - find the rate for the requested packet
 589  *
 590  * Returns the ieee80211_rate structure allocated by the driver.
 591  *
 592  * The rate control algorithm has no internal mapping between hw_mode's
 593  * 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 across
 596  * the entire A/B/G spectrum vs. being limited to just one particular
 597  * hw_mode.
 598  *
 599  * As such, we can't convert the index obtained below into the hw_mode's
 600  * rate table and must reference the driver allocated rate table
 601  *
 602  */
 603 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 604                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 605 {
 606         struct ieee80211_supported_band *sband = txrc->sband;
 607         struct sk_buff *skb = txrc->skb;
 608         u8 low = IWL_RATE_INVALID;
 609         u8 high = IWL_RATE_INVALID;
 610         u16 high_low;
 611         int index;
 612         struct iwl3945_rs_sta *rs_sta = priv_sta;
 613         struct iwl3945_rate_scale_data *window = NULL;
 614         int current_tpt = IWL_INV_TPT;
 615         int low_tpt = IWL_INV_TPT;
 616         int high_tpt = IWL_INV_TPT;
 617         u32 fail_count;
 618         s8 scale_action = 0;
 619         unsigned long flags;
 620         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 621         u16 fc, rate_mask;
 622         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_r;
 623         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 624
 625         IWL_DEBUG_RATE("enter\n");
 626
 627         /* Send management frames and broadcast/multicast data using lowest
 628          * rate. */
 629         fc = le16_to_cpu(hdr->frame_control);
 630         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 631             is_multicast_ether_addr(hdr->addr1) ||
 632             !sta || !priv_sta) {
 633                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 634                 info->control.rates[0].idx = rate_lowest_index(sband, sta);
 635                 return;
 636         }
 637
 638         rate_mask = sta->supp_rates[sband->band];
 639         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT - 1);
 640
 641         if (sband->band == IEEE80211_BAND_5GHZ)
 642                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 643
 644         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 645             !rs_sta->ibss_sta_added) {
 646                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 647
 648                 if (sta_id == IWL_INVALID_STATION) {
 649                         IWL_DEBUG_RATE("LQ: ADD station %pm\n",
 650                                        hdr->addr1);
 651                         sta_id = iwl3945_add_station(priv,
 652                                     hdr->addr1, 0, CMD_ASYNC);
 653                 }
 654                 if (sta_id != IWL_INVALID_STATION)
 655                         rs_sta->ibss_sta_added = 1;
 656         }
 657
 658         spin_lock_irqsave(&rs_sta->lock, flags);
 659
 660         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 661                 index = rs_sta->start_rate;
 662                 rs_sta->start_rate = IWL_RATE_INVALID;
 663         }
 664
 665         window = &(rs_sta->win[index]);
 666
 667         fail_count = window->counter - window->success_counter;
 668
 669         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 670              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 671                 window->average_tpt = IWL_INV_TPT;
 672                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 673
 674                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 675                                "counter: %d, success_counter: %d, "
 676                                "expected_tpt is %sNULL\n",
 677                                index,
 678                                window->counter,
 679                                window->success_counter,
 680                                rs_sta->expected_tpt ? "not " : "");
 681                 goto out;
 682
 683         }
 684
 685         window->average_tpt = ((window->success_ratio *
 686                                 rs_sta->expected_tpt[index] + 64) / 128);
 687         current_tpt = window->average_tpt;
 688
 689         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 690                                              sband->band);
 691         low = high_low & 0xff;
 692         high = (high_low >> 8) & 0xff;
 693
 694         if (low != IWL_RATE_INVALID)
 695                 low_tpt = rs_sta->win[low].average_tpt;
 696
 697         if (high != IWL_RATE_INVALID)
 698                 high_tpt = rs_sta->win[high].average_tpt;
 699
 700         spin_unlock_irqrestore(&rs_sta->lock, flags);
 701
 702         scale_action = 1;
 703
 704         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 705                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 706                 scale_action = -1;
 707         } else if ((low_tpt == IWL_INV_TPT) && (high_tpt == IWL_INV_TPT))
 708                 scale_action = 1;
 709         else if ((low_tpt != IWL_INV_TPT) && (high_tpt != IWL_INV_TPT) &&
 710                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 711                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 712                                "current_tpt [%d]\n",
 713                                low_tpt, high_tpt, current_tpt);
 714                 scale_action = 0;
 715         } else {
 716                 if (high_tpt != IWL_INV_TPT) {
 717                         if (high_tpt > current_tpt)
 718                                 scale_action = 1;
 719                         else {
 720                                 IWL_DEBUG_RATE
 721                                     ("decrease rate because of high tpt\n");
 722                                 scale_action = -1;
 723                         }
 724                 } else if (low_tpt != IWL_INV_TPT) {
 725                         if (low_tpt > current_tpt) {
 726                                 IWL_DEBUG_RATE
 727                                     ("decrease rate because of low tpt\n");
 728                                 scale_action = -1;
 729                         } else
 730                                 scale_action = 1;
 731                 }
 732         }
 733
 734         if ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 735             (current_tpt > window->average_tpt)) {
 736                 IWL_DEBUG_RATE("No action -- success_ratio [%d] > HIGH_TH or "
 737                                "current_tpt [%d] > average_tpt [%d]\n",
 738                                window->success_ratio,
 739                                current_tpt, window->average_tpt);
 740                 scale_action = 0;
 741         }
 742
 743         switch (scale_action) {
 744         case -1:
 745                 if (low != IWL_RATE_INVALID)
 746                         index = low;
 747                 break;
 748
 749         case 1:
 750                 if (high != IWL_RATE_INVALID)
 751                         index = high;
 752
 753                 break;
 754
 755         case 0:
 756         default:
 757                 break;
 758         }
 759
 760         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 761                        index, scale_action, low, high);
 762
 763  out:
 764
 765         rs_sta->last_txrate_idx = index;
 766         if (sband->band == IEEE80211_BAND_5GHZ)
 767                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
 768                                 IWL_FIRST_OFDM_RATE;
 769         else
 770                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
 771
 772         IWL_DEBUG_RATE("leave: %d\n", index);
 773 }
 774
 775 static struct rate_control_ops rs_ops = {
 776         .module = NULL,
 777         .name = RS_NAME,
 778         .tx_status = rs_tx_status,
 779         .get_rate = rs_get_rate,
 780         .rate_init = rs_rate_init,
 781         .alloc = rs_alloc,
 782         .free = rs_free,
 783         .alloc_sta = rs_alloc_sta,
 784         .free_sta = rs_free_sta,
 785 };
 786
 787 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 788 {
 789         struct iwl3945_priv *priv = hw->priv;
 790         s32 rssi = 0;
 791         unsigned long flags;
 792         struct iwl3945_rs_sta *rs_sta;
 793         struct ieee80211_sta *sta;
 794         struct iwl3945_sta_priv *psta;
 795
 796         IWL_DEBUG_RATE("enter\n");
 797
 798         rcu_read_lock();
 799
 800         sta = ieee80211_find_sta(hw, priv->stations[sta_id].sta.sta.addr);
 801         if (!sta) {
 802                 rcu_read_unlock();
 803                 return;
 804         }
 805
 806         psta = (void *) sta->drv_priv;
 807         rs_sta = psta->rs_sta;
 808
 809         spin_lock_irqsave(&rs_sta->lock, flags);
 810
 811         rs_sta->tgg = 0;
 812         switch (priv->band) {
 813         case IEEE80211_BAND_2GHZ:
 814                 /* TODO: this always does G, not a regression */
 815                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 816                         rs_sta->tgg = 1;
 817                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 818                 } else
 819                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 820                 break;
 821
 822         case IEEE80211_BAND_5GHZ:
 823                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 824                 break;
 825         case IEEE80211_NUM_BANDS:
 826                 BUG();
 827                 break;
 828         }
 829
 830         spin_unlock_irqrestore(&rs_sta->lock, flags);
 831
 832         rssi = priv->last_rx_rssi;
 833         if (rssi == 0)
 834                 rssi = IWL_MIN_RSSI_VAL;
 835
 836         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 837
 838         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 839
 840         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 841                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 842                        iwl3945_rates[rs_sta->start_rate].plcp);
 843         rcu_read_unlock();
 844 }
 845
 846 int iwl3945_rate_control_register(void)
 847 {
 848         return ieee80211_rate_control_register(&rs_ops);
 849 }
 850
 851 void iwl3945_rate_control_unregister(void)
 852 {
 853         ieee80211_rate_control_unregister(&rs_ops);
 854 }
 855
 856