git.oblomov.eu Git - linux-2.6/blob - 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_clear(void *priv)
 359 {
 360         return;
 361 }
 362
 363
 364 static void *rs_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 365 {
 366         struct iwl3945_rs_sta *rs_sta;
 367         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 368         int i;
 369
 370         /*
 371          * XXX: If it's using sta->drv_priv anyway, it might
 372          *      as well just put all the information there.
 373          */
 374
 375         IWL_DEBUG_RATE("enter\n");
 376
 377         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 378         if (!rs_sta) {
 379                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 380                 return NULL;
 381         }
 382
 383         psta->rs_sta = rs_sta;
 384
 385         spin_lock_init(&rs_sta->lock);
 386
 387         rs_sta->start_rate = IWL_RATE_INVALID;
 388
 389         /* default to just 802.11b */
 390         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 391
 392         rs_sta->last_partial_flush = jiffies;
 393         rs_sta->last_flush = jiffies;
 394         rs_sta->flush_time = IWL_RATE_FLUSH;
 395         rs_sta->last_tx_packets = 0;
 396         rs_sta->ibss_sta_added = 0;
 397
 398         init_timer(&rs_sta->rate_scale_flush);
 399         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 400         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 401
 402         for (i = 0; i < IWL_RATE_COUNT; i++)
 403                 iwl3945_clear_window(&rs_sta->win[i]);
 404
 405         IWL_DEBUG_RATE("leave\n");
 406
 407         return rs_sta;
 408 }
 409
 410 static void rs_free_sta(void *priv, struct ieee80211_sta *sta,
 411                         void *priv_sta)
 412 {
 413         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 414         struct iwl3945_rs_sta *rs_sta = priv_sta;
 415
 416         psta->rs_sta = NULL;
 417
 418         IWL_DEBUG_RATE("enter\n");
 419         del_timer_sync(&rs_sta->rate_scale_flush);
 420         kfree(rs_sta);
 421         IWL_DEBUG_RATE("leave\n");
 422 }
 423
 424
 425 /*
 426  * get ieee prev rate from rate scale table.
 427  * for A and B mode we need to overright prev
 428  * value
 429  */
 430 static int rs_adjust_next_rate(struct iwl3945_priv *priv, int rate)
 431 {
 432         int next_rate = iwl3945_get_prev_ieee_rate(rate);
 433
 434         switch (priv->band) {
 435         case IEEE80211_BAND_5GHZ:
 436                 if (rate == IWL_RATE_12M_INDEX)
 437                         next_rate = IWL_RATE_9M_INDEX;
 438                 else if (rate == IWL_RATE_6M_INDEX)
 439                         next_rate = IWL_RATE_6M_INDEX;
 440                 break;
 441 /* XXX cannot be invoked in current mac80211 so not a regression
 442         case MODE_IEEE80211B:
 443                 if (rate == IWL_RATE_11M_INDEX_TABLE)
 444                         next_rate = IWL_RATE_5M_INDEX_TABLE;
 445                 break;
 446  */
 447         default:
 448                 break;
 449         }
 450
 451         return next_rate;
 452 }
 453 /**
 454  * rs_tx_status - Update rate control values based on Tx results
 455  *
 456  * NOTE: Uses iwl3945_priv->retry_rate for the # of retries attempted by
 457  * the hardware for each rate.
 458  */
 459 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 460                          struct ieee80211_sta *sta, void *priv_sta,
 461                          struct sk_buff *skb)
 462 {
 463         u8 retries, current_count;
 464         int scale_rate_index, first_index, last_index;
 465         unsigned long flags;
 466         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 467         struct iwl3945_rs_sta *rs_sta = priv_sta;
 468         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 469
 470         IWL_DEBUG_RATE("enter\n");
 471
 472         retries = info->status.retry_count;
 473         first_index = sband->bitrates[info->tx_rate_idx].hw_value;
 474         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 475                 IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);
 476                 return;
 477         }
 478
 479         if (!priv_sta) {
 480                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 481                 return;
 482         }
 483
 484         rs_sta->tx_packets++;
 485
 486         scale_rate_index = first_index;
 487         last_index = first_index;
 488
 489         /*
 490          * Update the window for each rate.  We determine which rates
 491          * were Tx'd based on the total number of retries vs. the number
 492          * of retries configured for each rate -- currently set to the
 493          * priv value 'retry_rate' vs. rate specific
 494          *
 495          * On exit from this while loop last_index indicates the rate
 496          * at which the frame was finally transmitted (or failed if no
 497          * ACK)
 498          */
 499         while (retries > 0) {
 500                 if (retries < priv->retry_rate) {
 501                         current_count = retries;
 502                         last_index = scale_rate_index;
 503                 } else {
 504                         current_count = priv->retry_rate;
 505                         last_index = rs_adjust_next_rate(priv,
 506                                                          scale_rate_index);
 507                 }
 508
 509                 /* Update this rate accounting for as many retries
 510                  * as was used for it (per current_count) */
 511                 iwl3945_collect_tx_data(rs_sta,
 512                                     &rs_sta->win[scale_rate_index],
 513                                     0, current_count);
 514                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 515                                scale_rate_index, current_count);
 516
 517                 retries -= current_count;
 518
 519                 if (retries)
 520                         scale_rate_index =
 521                             rs_adjust_next_rate(priv, scale_rate_index);
 522         }
 523
 524
 525         /* Update the last index window with success/failure based on ACK */
 526         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 527                        last_index,
 528                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 529                        "success" : "failure");
 530         iwl3945_collect_tx_data(rs_sta,
 531                             &rs_sta->win[last_index],
 532                             info->flags & IEEE80211_TX_STAT_ACK, 1);
 533
 534         /* We updated the rate scale window -- if its been more than
 535          * flush_time since the last run, schedule the flush
 536          * again */
 537         spin_lock_irqsave(&rs_sta->lock, flags);
 538
 539         if (!rs_sta->flush_pending &&
 540             time_after(jiffies, rs_sta->last_partial_flush +
 541                        rs_sta->flush_time)) {
 542
 543                 rs_sta->flush_pending = 1;
 544                 mod_timer(&rs_sta->rate_scale_flush,
 545                           jiffies + rs_sta->flush_time);
 546         }
 547
 548         spin_unlock_irqrestore(&rs_sta->lock, flags);
 549
 550         IWL_DEBUG_RATE("leave\n");
 551
 552         return;
 553 }
 554
 555 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 556                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 557 {
 558         u8 high = IWL_RATE_INVALID;
 559         u8 low = IWL_RATE_INVALID;
 560
 561         /* 802.11A walks to the next literal adjacent rate in
 562          * the rate table */
 563         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 564                 int i;
 565                 u32 mask;
 566
 567                 /* Find the previous rate that is in the rate mask */
 568                 i = index - 1;
 569                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 570                         if (rate_mask & mask) {
 571                                 low = i;
 572                                 break;
 573                         }
 574                 }
 575
 576                 /* Find the next rate that is in the rate mask */
 577                 i = index + 1;
 578                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
 579                         if (rate_mask & mask) {
 580                                 high = i;
 581                                 break;
 582                         }
 583                 }
 584
 585                 return (high << 8) | low;
 586         }
 587
 588         low = index;
 589         while (low != IWL_RATE_INVALID) {
 590                 if (rs_sta->tgg)
 591                         low = iwl3945_rates[low].prev_rs_tgg;
 592                 else
 593                         low = iwl3945_rates[low].prev_rs;
 594                 if (low == IWL_RATE_INVALID)
 595                         break;
 596                 if (rate_mask & (1 << low))
 597                         break;
 598                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 599         }
 600
 601         high = index;
 602         while (high != IWL_RATE_INVALID) {
 603                 if (rs_sta->tgg)
 604                         high = iwl3945_rates[high].next_rs_tgg;
 605                 else
 606                         high = iwl3945_rates[high].next_rs;
 607                 if (high == IWL_RATE_INVALID)
 608                         break;
 609                 if (rate_mask & (1 << high))
 610                         break;
 611                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 612         }
 613
 614         return (high << 8) | low;
 615 }
 616
 617 /**
 618  * rs_get_rate - find the rate for the requested packet
 619  *
 620  * Returns the ieee80211_rate structure allocated by the driver.
 621  *
 622  * The rate control algorithm has no internal mapping between hw_mode's
 623  * rate ordering and the rate ordering used by the rate control algorithm.
 624  *
 625  * The rate control algorithm uses a single table of rates that goes across
 626  * the entire A/B/G spectrum vs. being limited to just one particular
 627  * hw_mode.
 628  *
 629  * As such, we can't convert the index obtained below into the hw_mode's
 630  * rate table and must reference the driver allocated rate table
 631  *
 632  */
 633 static void rs_get_rate(void *priv_r, struct ieee80211_supported_band *sband,
 634                         struct ieee80211_sta *sta, void *priv_sta,
 635                         struct sk_buff *skb, struct rate_selection *sel)
 636 {
 637         u8 low = IWL_RATE_INVALID;
 638         u8 high = IWL_RATE_INVALID;
 639         u16 high_low;
 640         int index;
 641         struct iwl3945_rs_sta *rs_sta = priv_sta;
 642         struct iwl3945_rate_scale_data *window = NULL;
 643         int current_tpt = IWL_INV_TPT;
 644         int low_tpt = IWL_INV_TPT;
 645         int high_tpt = IWL_INV_TPT;
 646         u32 fail_count;
 647         s8 scale_action = 0;
 648         unsigned long flags;
 649         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 650         u16 fc, rate_mask;
 651         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_r;
 652         DECLARE_MAC_BUF(mac);
 653
 654         IWL_DEBUG_RATE("enter\n");
 655
 656         /* Send management frames and broadcast/multicast data using lowest
 657          * rate. */
 658         fc = le16_to_cpu(hdr->frame_control);
 659         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 660             is_multicast_ether_addr(hdr->addr1) ||
 661             !sta || !priv_sta) {
 662                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 663                 sel->rate_idx = rate_lowest_index(sband, sta);
 664                 return;
 665         }
 666
 667         rate_mask = sta->supp_rates[sband->band];
 668         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT - 1);
 669
 670         if (sband->band == IEEE80211_BAND_5GHZ)
 671                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 672
 673         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 674             !rs_sta->ibss_sta_added) {
 675                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 676
 677                 if (sta_id == IWL_INVALID_STATION) {
 678                         IWL_DEBUG_RATE("LQ: ADD station %s\n",
 679                                        print_mac(mac, hdr->addr1));
 680                         sta_id = iwl3945_add_station(priv,
 681                                     hdr->addr1, 0, CMD_ASYNC);
 682                 }
 683                 if (sta_id != IWL_INVALID_STATION)
 684                         rs_sta->ibss_sta_added = 1;
 685         }
 686
 687         spin_lock_irqsave(&rs_sta->lock, flags);
 688
 689         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 690                 index = rs_sta->start_rate;
 691                 rs_sta->start_rate = IWL_RATE_INVALID;
 692         }
 693
 694         window = &(rs_sta->win[index]);
 695
 696         fail_count = window->counter - window->success_counter;
 697
 698         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 699              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 700                 window->average_tpt = IWL_INV_TPT;
 701                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 702
 703                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 704                                "counter: %d, success_counter: %d, "
 705                                "expected_tpt is %sNULL\n",
 706                                index,
 707                                window->counter,
 708                                window->success_counter,
 709                                rs_sta->expected_tpt ? "not " : "");
 710                 goto out;
 711
 712         }
 713
 714         window->average_tpt = ((window->success_ratio *
 715                                 rs_sta->expected_tpt[index] + 64) / 128);
 716         current_tpt = window->average_tpt;
 717
 718         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 719                                              sband->band);
 720         low = high_low & 0xff;
 721         high = (high_low >> 8) & 0xff;
 722
 723         if (low != IWL_RATE_INVALID)
 724                 low_tpt = rs_sta->win[low].average_tpt;
 725
 726         if (high != IWL_RATE_INVALID)
 727                 high_tpt = rs_sta->win[high].average_tpt;
 728
 729         spin_unlock_irqrestore(&rs_sta->lock, flags);
 730
 731         scale_action = 1;
 732
 733         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 734                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 735                 scale_action = -1;
 736         } else if ((low_tpt == IWL_INV_TPT) && (high_tpt == IWL_INV_TPT))
 737                 scale_action = 1;
 738         else if ((low_tpt != IWL_INV_TPT) && (high_tpt != IWL_INV_TPT) &&
 739                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 740                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 741                                "current_tpt [%d]\n",
 742                                low_tpt, high_tpt, current_tpt);
 743                 scale_action = 0;
 744         } else {
 745                 if (high_tpt != IWL_INV_TPT) {
 746                         if (high_tpt > current_tpt)
 747                                 scale_action = 1;
 748                         else {
 749                                 IWL_DEBUG_RATE
 750                                     ("decrease rate because of high tpt\n");
 751                                 scale_action = -1;
 752                         }
 753                 } else if (low_tpt != IWL_INV_TPT) {
 754                         if (low_tpt > current_tpt) {
 755                                 IWL_DEBUG_RATE
 756                                     ("decrease rate because of low tpt\n");
 757                                 scale_action = -1;
 758                         } else
 759                                 scale_action = 1;
 760                 }
 761         }
 762
 763         if ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 764             (current_tpt > window->average_tpt)) {
 765                 IWL_DEBUG_RATE("No action -- success_ratio [%d] > HIGH_TH or "
 766                                "current_tpt [%d] > average_tpt [%d]\n",
 767                                window->success_ratio,
 768                                current_tpt, window->average_tpt);
 769                 scale_action = 0;
 770         }
 771
 772         switch (scale_action) {
 773         case -1:
 774                 if (low != IWL_RATE_INVALID)
 775                         index = low;
 776                 break;
 777
 778         case 1:
 779                 if (high != IWL_RATE_INVALID)
 780                         index = high;
 781
 782                 break;
 783
 784         case 0:
 785         default:
 786                 break;
 787         }
 788
 789         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 790                        index, scale_action, low, high);
 791
 792  out:
 793
 794         rs_sta->last_txrate_idx = index;
 795         if (sband->band == IEEE80211_BAND_5GHZ)
 796                 sel->rate_idx = rs_sta->last_txrate_idx - IWL_FIRST_OFDM_RATE;
 797         else
 798                 sel->rate_idx = rs_sta->last_txrate_idx;
 799
 800         IWL_DEBUG_RATE("leave: %d\n", index);
 801 }
 802
 803 static struct rate_control_ops rs_ops = {
 804         .module = NULL,
 805         .name = RS_NAME,
 806         .tx_status = rs_tx_status,
 807         .get_rate = rs_get_rate,
 808         .rate_init = rs_rate_init,
 809         .clear = rs_clear,
 810         .alloc = rs_alloc,
 811         .free = rs_free,
 812         .alloc_sta = rs_alloc_sta,
 813         .free_sta = rs_free_sta,
 814 };
 815
 816 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 817 {
 818         struct iwl3945_priv *priv = hw->priv;
 819         s32 rssi = 0;
 820         unsigned long flags;
 821         struct iwl3945_rs_sta *rs_sta;
 822         struct ieee80211_sta *sta;
 823         struct iwl3945_sta_priv *psta;
 824
 825         IWL_DEBUG_RATE("enter\n");
 826
 827         rcu_read_lock();
 828
 829         sta = ieee80211_find_sta(hw, priv->stations[sta_id].sta.sta.addr);
 830         psta = (void *) sta->drv_priv;
 831         if (!sta || !psta) {
 832                 IWL_DEBUG_RATE("leave - no private rate data!\n");
 833                 rcu_read_unlock();
 834                 return;
 835         }
 836
 837         rs_sta = psta->rs_sta;
 838
 839         spin_lock_irqsave(&rs_sta->lock, flags);
 840
 841         rs_sta->tgg = 0;
 842         switch (priv->band) {
 843         case IEEE80211_BAND_2GHZ:
 844                 /* TODO: this always does G, not a regression */
 845                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 846                         rs_sta->tgg = 1;
 847                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 848                 } else
 849                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 850                 break;
 851
 852         case IEEE80211_BAND_5GHZ:
 853                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 854                 break;
 855         case IEEE80211_NUM_BANDS:
 856                 BUG();
 857                 break;
 858         }
 859
 860         rcu_read_unlock();
 861         spin_unlock_irqrestore(&rs_sta->lock, flags);
 862
 863         rssi = priv->last_rx_rssi;
 864         if (rssi == 0)
 865                 rssi = IWL_MIN_RSSI_VAL;
 866
 867         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 868
 869         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 870
 871         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 872                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 873                        iwl3945_rates[rs_sta->start_rate].plcp);
 874 }
 875
 876 int iwl3945_rate_control_register(void)
 877 {
 878         return ieee80211_rate_control_register(&rs_ops);
 879 }
 880
 881 void iwl3945_rate_control_unregister(void)
 882 {
 883         ieee80211_rate_control_unregister(&rs_ops);
 884 }
 885
 886