iwlwifi: Use RTS/CTS as the preferred protection mechanism for 6000 series
[linux-2.6.git] / drivers / net / wireless / iwlwifi / iwl-agn-rs.c
1 /******************************************************************************
2  *
3  * Copyright(c) 2005 - 2009 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  *  Intel Linux Wireless <ilw@linux.intel.com>
23  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
24  *
25  *****************************************************************************/
26 #include <linux/kernel.h>
27 #include <linux/init.h>
28 #include <linux/skbuff.h>
29 #include <linux/wireless.h>
30 #include <net/mac80211.h>
31
32 #include <linux/netdevice.h>
33 #include <linux/etherdevice.h>
34 #include <linux/delay.h>
35
36 #include <linux/workqueue.h>
37
38 #include "iwl-dev.h"
39 #include "iwl-sta.h"
40 #include "iwl-core.h"
41
42 #define RS_NAME "iwl-agn-rs"
43
44 #define NUM_TRY_BEFORE_ANT_TOGGLE 1
45 #define IWL_NUMBER_TRY      1
46 #define IWL_HT_NUMBER_TRY   3
47
48 #define IWL_RATE_MAX_WINDOW             62      /* # tx in history window */
49 #define IWL_RATE_MIN_FAILURE_TH         6       /* min failures to calc tpt */
50 #define IWL_RATE_MIN_SUCCESS_TH         8       /* min successes to calc tpt */
51
52 /* max allowed rate miss before sync LQ cmd */
53 #define IWL_MISSED_RATE_MAX             15
54 /* max time to accum history 2 seconds */
55 #define IWL_RATE_SCALE_FLUSH_INTVL   (3*HZ)
56
57 static u8 rs_ht_to_legacy[] = {
58         IWL_RATE_6M_INDEX, IWL_RATE_6M_INDEX,
59         IWL_RATE_6M_INDEX, IWL_RATE_6M_INDEX,
60         IWL_RATE_6M_INDEX,
61         IWL_RATE_6M_INDEX, IWL_RATE_9M_INDEX,
62         IWL_RATE_12M_INDEX, IWL_RATE_18M_INDEX,
63         IWL_RATE_24M_INDEX, IWL_RATE_36M_INDEX,
64         IWL_RATE_48M_INDEX, IWL_RATE_54M_INDEX
65 };
66
67 static const u8 ant_toggle_lookup[] = {
68         /*ANT_NONE -> */ ANT_NONE,
69         /*ANT_A    -> */ ANT_B,
70         /*ANT_B    -> */ ANT_C,
71         /*ANT_AB   -> */ ANT_BC,
72         /*ANT_C    -> */ ANT_A,
73         /*ANT_AC   -> */ ANT_AB,
74         /*ANT_BC   -> */ ANT_AC,
75         /*ANT_ABC  -> */ ANT_ABC,
76 };
77
78 /**
79  * struct iwl_rate_scale_data -- tx success history for one rate
80  */
81 struct iwl_rate_scale_data {
82         u64 data;               /* bitmap of successful frames */
83         s32 success_counter;    /* number of frames successful */
84         s32 success_ratio;      /* per-cent * 128  */
85         s32 counter;            /* number of frames attempted */
86         s32 average_tpt;        /* success ratio * expected throughput */
87         unsigned long stamp;
88 };
89
90 /**
91  * struct iwl_scale_tbl_info -- tx params and success history for all rates
92  *
93  * There are two of these in struct iwl_lq_sta,
94  * one for "active", and one for "search".
95  */
96 struct iwl_scale_tbl_info {
97         enum iwl_table_type lq_type;
98         u8 ant_type;
99         u8 is_SGI;      /* 1 = short guard interval */
100         u8 is_ht40;     /* 1 = 40 MHz channel width */
101         u8 is_dup;      /* 1 = duplicated data streams */
102         u8 action;      /* change modulation; IWL_[LEGACY/SISO/MIMO]_SWITCH_* */
103         u8 max_search;  /* maximun number of tables we can search */
104         s32 *expected_tpt;      /* throughput metrics; expected_tpt_G, etc. */
105         u32 current_rate;  /* rate_n_flags, uCode API format */
106         struct iwl_rate_scale_data win[IWL_RATE_COUNT]; /* rate histories */
107 };
108
109 struct iwl_traffic_load {
110         unsigned long time_stamp;       /* age of the oldest statistics */
111         u32 packet_count[TID_QUEUE_MAX_SIZE];   /* packet count in this time
112                                                  * slice */
113         u32 total;                      /* total num of packets during the
114                                          * last TID_MAX_TIME_DIFF */
115         u8 queue_count;                 /* number of queues that has
116                                          * been used since the last cleanup */
117         u8 head;                        /* start of the circular buffer */
118 };
119
120 /**
121  * struct iwl_lq_sta -- driver's rate scaling private structure
122  *
123  * Pointer to this gets passed back and forth between driver and mac80211.
124  */
125 struct iwl_lq_sta {
126         u8 active_tbl;          /* index of active table, range 0-1 */
127         u8 enable_counter;      /* indicates HT mode */
128         u8 stay_in_tbl;         /* 1: disallow, 0: allow search for new mode */
129         u8 search_better_tbl;   /* 1: currently trying alternate mode */
130         s32 last_tpt;
131
132         /* The following determine when to search for a new mode */
133         u32 table_count_limit;
134         u32 max_failure_limit;  /* # failed frames before new search */
135         u32 max_success_limit;  /* # successful frames before new search */
136         u32 table_count;
137         u32 total_failed;       /* total failed frames, any/all rates */
138         u32 total_success;      /* total successful frames, any/all rates */
139         u64 flush_timer;        /* time staying in mode before new search */
140
141         u8 action_counter;      /* # mode-switch actions tried */
142         u8 is_green;
143         u8 is_dup;
144         enum ieee80211_band band;
145         u8 ibss_sta_added;
146
147         /* The following are bitmaps of rates; IWL_RATE_6M_MASK, etc. */
148         u32 supp_rates;
149         u16 active_legacy_rate;
150         u16 active_siso_rate;
151         u16 active_mimo2_rate;
152         u16 active_mimo3_rate;
153         u16 active_rate_basic;
154         s8 max_rate_idx;     /* Max rate set by user */
155         u8 missed_rate_counter;
156
157         struct iwl_link_quality_cmd lq;
158         struct iwl_scale_tbl_info lq_info[LQ_SIZE]; /* "active", "search" */
159         struct iwl_traffic_load load[TID_MAX_LOAD_COUNT];
160         u8 tx_agg_tid_en;
161 #ifdef CONFIG_MAC80211_DEBUGFS
162         struct dentry *rs_sta_dbgfs_scale_table_file;
163         struct dentry *rs_sta_dbgfs_stats_table_file;
164         struct dentry *rs_sta_dbgfs_rate_scale_data_file;
165         struct dentry *rs_sta_dbgfs_tx_agg_tid_en_file;
166         u32 dbg_fixed_rate;
167 #endif
168         struct iwl_priv *drv;
169
170         /* used to be in sta_info */
171         int last_txrate_idx;
172         /* last tx rate_n_flags */
173         u32 last_rate_n_flags;
174 };
175
176 static void rs_rate_scale_perform(struct iwl_priv *priv,
177                                    struct sk_buff *skb,
178                                    struct ieee80211_sta *sta,
179                                    struct iwl_lq_sta *lq_sta);
180 static void rs_fill_link_cmd(struct iwl_priv *priv,
181                              struct iwl_lq_sta *lq_sta, u32 rate_n_flags);
182
183
184 #ifdef CONFIG_MAC80211_DEBUGFS
185 static void rs_dbgfs_set_mcs(struct iwl_lq_sta *lq_sta,
186                              u32 *rate_n_flags, int index);
187 #else
188 static void rs_dbgfs_set_mcs(struct iwl_lq_sta *lq_sta,
189                              u32 *rate_n_flags, int index)
190 {}
191 #endif
192
193 /*
194  * Expected throughput metrics for following rates:
195  * 1, 2, 5.5, 11, 6, 9, 12, 18, 24, 36, 48, 54, 60 MBits
196  * "G" is the only table that supports CCK (the first 4 rates).
197  */
198
199 static s32 expected_tpt_A[IWL_RATE_COUNT] = {
200         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186, 186
201 };
202
203 static s32 expected_tpt_G[IWL_RATE_COUNT] = {
204         7, 13, 35, 58, 40, 57, 72, 98, 121, 154, 177, 186, 186
205 };
206
207 static s32 expected_tpt_siso20MHz[IWL_RATE_COUNT] = {
208         0, 0, 0, 0, 42, 42, 76, 102, 124, 159, 183, 193, 202
209 };
210
211 static s32 expected_tpt_siso20MHzSGI[IWL_RATE_COUNT] = {
212         0, 0, 0, 0, 46, 46, 82, 110, 132, 168, 192, 202, 211
213 };
214
215 static s32 expected_tpt_mimo2_20MHz[IWL_RATE_COUNT] = {
216         0, 0, 0, 0, 74, 74, 123, 155, 179, 214, 236, 244, 251
217 };
218
219 static s32 expected_tpt_mimo2_20MHzSGI[IWL_RATE_COUNT] = {
220         0, 0, 0, 0, 81, 81, 131, 164, 188, 222, 243, 251, 257
221 };
222
223 static s32 expected_tpt_siso40MHz[IWL_RATE_COUNT] = {
224         0, 0, 0, 0, 77, 77, 127, 160, 184, 220, 242, 250, 257
225 };
226
227 static s32 expected_tpt_siso40MHzSGI[IWL_RATE_COUNT] = {
228         0, 0, 0, 0, 83, 83, 135, 169, 193, 229, 250, 257, 264
229 };
230
231 static s32 expected_tpt_mimo2_40MHz[IWL_RATE_COUNT] = {
232         0, 0, 0, 0, 123, 123, 182, 214, 235, 264, 279, 285, 289
233 };
234
235 static s32 expected_tpt_mimo2_40MHzSGI[IWL_RATE_COUNT] = {
236         0, 0, 0, 0, 131, 131, 191, 222, 242, 270, 284, 289, 293
237 };
238
239 /* Expected throughput metric MIMO3 */
240 static s32 expected_tpt_mimo3_20MHz[IWL_RATE_COUNT] = {
241         0, 0, 0, 0, 99, 99, 153, 186, 208, 239, 256, 263, 268
242 };
243
244 static s32 expected_tpt_mimo3_20MHzSGI[IWL_RATE_COUNT] = {
245         0, 0, 0, 0, 106, 106, 162, 194, 215, 246, 262, 268, 273
246 };
247
248 static s32 expected_tpt_mimo3_40MHz[IWL_RATE_COUNT] = {
249         0, 0, 0, 0, 152, 152, 211, 239, 255, 279, 290, 294, 297
250 };
251
252 static s32 expected_tpt_mimo3_40MHzSGI[IWL_RATE_COUNT] = {
253         0, 0, 0, 0, 160, 160, 219, 245, 261, 284, 294, 297, 300
254 };
255
256 /* mbps, mcs */
257 const static struct iwl_rate_mcs_info iwl_rate_mcs[IWL_RATE_COUNT] = {
258   {"1", ""},
259   {"2", ""},
260   {"5.5", ""},
261   {"11", ""},
262   {"6", "BPSK 1/2"},
263   {"9", "BPSK 1/2"},
264   {"12", "QPSK 1/2"},
265   {"18", "QPSK 3/4"},
266   {"24", "16QAM 1/2"},
267   {"36", "16QAM 3/4"},
268   {"48", "64QAM 2/3"},
269   {"54", "64QAM 3/4"},
270   {"60", "64QAM 5/6"}
271 };
272
273 #define MCS_INDEX_PER_STREAM    (8)
274
275 static inline u8 rs_extract_rate(u32 rate_n_flags)
276 {
277         return (u8)(rate_n_flags & 0xFF);
278 }
279
280 static void rs_rate_scale_clear_window(struct iwl_rate_scale_data *window)
281 {
282         window->data = 0;
283         window->success_counter = 0;
284         window->success_ratio = IWL_INVALID_VALUE;
285         window->counter = 0;
286         window->average_tpt = IWL_INVALID_VALUE;
287         window->stamp = 0;
288 }
289
290 static inline u8 rs_is_valid_ant(u8 valid_antenna, u8 ant_type)
291 {
292         return (ant_type & valid_antenna) == ant_type;
293 }
294
295 /*
296  *      removes the old data from the statistics. All data that is older than
297  *      TID_MAX_TIME_DIFF, will be deleted.
298  */
299 static void rs_tl_rm_old_stats(struct iwl_traffic_load *tl, u32 curr_time)
300 {
301         /* The oldest age we want to keep */
302         u32 oldest_time = curr_time - TID_MAX_TIME_DIFF;
303
304         while (tl->queue_count &&
305                (tl->time_stamp < oldest_time)) {
306                 tl->total -= tl->packet_count[tl->head];
307                 tl->packet_count[tl->head] = 0;
308                 tl->time_stamp += TID_QUEUE_CELL_SPACING;
309                 tl->queue_count--;
310                 tl->head++;
311                 if (tl->head >= TID_QUEUE_MAX_SIZE)
312                         tl->head = 0;
313         }
314 }
315
316 /*
317  *      increment traffic load value for tid and also remove
318  *      any old values if passed the certain time period
319  */
320 static u8 rs_tl_add_packet(struct iwl_lq_sta *lq_data,
321                            struct ieee80211_hdr *hdr)
322 {
323         u32 curr_time = jiffies_to_msecs(jiffies);
324         u32 time_diff;
325         s32 index;
326         struct iwl_traffic_load *tl = NULL;
327         u8 tid;
328
329         if (ieee80211_is_data_qos(hdr->frame_control)) {
330                 u8 *qc = ieee80211_get_qos_ctl(hdr);
331                 tid = qc[0] & 0xf;
332         } else
333                 return MAX_TID_COUNT;
334
335         if (unlikely(tid >= TID_MAX_LOAD_COUNT))
336                 return MAX_TID_COUNT;
337
338         tl = &lq_data->load[tid];
339
340         curr_time -= curr_time % TID_ROUND_VALUE;
341
342         /* Happens only for the first packet. Initialize the data */
343         if (!(tl->queue_count)) {
344                 tl->total = 1;
345                 tl->time_stamp = curr_time;
346                 tl->queue_count = 1;
347                 tl->head = 0;
348                 tl->packet_count[0] = 1;
349                 return MAX_TID_COUNT;
350         }
351
352         time_diff = TIME_WRAP_AROUND(tl->time_stamp, curr_time);
353         index = time_diff / TID_QUEUE_CELL_SPACING;
354
355         /* The history is too long: remove data that is older than */
356         /* TID_MAX_TIME_DIFF */
357         if (index >= TID_QUEUE_MAX_SIZE)
358                 rs_tl_rm_old_stats(tl, curr_time);
359
360         index = (tl->head + index) % TID_QUEUE_MAX_SIZE;
361         tl->packet_count[index] = tl->packet_count[index] + 1;
362         tl->total = tl->total + 1;
363
364         if ((index + 1) > tl->queue_count)
365                 tl->queue_count = index + 1;
366
367         return tid;
368 }
369
370 /*
371         get the traffic load value for tid
372 */
373 static u32 rs_tl_get_load(struct iwl_lq_sta *lq_data, u8 tid)
374 {
375         u32 curr_time = jiffies_to_msecs(jiffies);
376         u32 time_diff;
377         s32 index;
378         struct iwl_traffic_load *tl = NULL;
379
380         if (tid >= TID_MAX_LOAD_COUNT)
381                 return 0;
382
383         tl = &(lq_data->load[tid]);
384
385         curr_time -= curr_time % TID_ROUND_VALUE;
386
387         if (!(tl->queue_count))
388                 return 0;
389
390         time_diff = TIME_WRAP_AROUND(tl->time_stamp, curr_time);
391         index = time_diff / TID_QUEUE_CELL_SPACING;
392
393         /* The history is too long: remove data that is older than */
394         /* TID_MAX_TIME_DIFF */
395         if (index >= TID_QUEUE_MAX_SIZE)
396                 rs_tl_rm_old_stats(tl, curr_time);
397
398         return tl->total;
399 }
400
401 static void rs_tl_turn_on_agg_for_tid(struct iwl_priv *priv,
402                                       struct iwl_lq_sta *lq_data, u8 tid,
403                                       struct ieee80211_sta *sta)
404 {
405         if (rs_tl_get_load(lq_data, tid) > IWL_AGG_LOAD_THRESHOLD) {
406                 IWL_DEBUG_HT(priv, "Starting Tx agg: STA: %pM tid: %d\n",
407                                 sta->addr, tid);
408                 ieee80211_start_tx_ba_session(priv->hw, sta->addr, tid);
409         }
410 }
411
412 static void rs_tl_turn_on_agg(struct iwl_priv *priv, u8 tid,
413                               struct iwl_lq_sta *lq_data,
414                               struct ieee80211_sta *sta)
415 {
416         if ((tid < TID_MAX_LOAD_COUNT))
417                 rs_tl_turn_on_agg_for_tid(priv, lq_data, tid, sta);
418         else if (tid == IWL_AGG_ALL_TID)
419                 for (tid = 0; tid < TID_MAX_LOAD_COUNT; tid++)
420                         rs_tl_turn_on_agg_for_tid(priv, lq_data, tid, sta);
421         if (priv->cfg->use_rts_for_ht) {
422                 /*
423                  * switch to RTS/CTS if it is the prefer protection method
424                  * for HT traffic
425                  */
426                 IWL_DEBUG_HT(priv, "use RTS/CTS protection for HT\n");
427                 priv->staging_rxon.flags &= ~RXON_FLG_SELF_CTS_EN;
428                 iwlcore_commit_rxon(priv);
429         }
430 }
431
432 static inline int get_num_of_ant_from_rate(u32 rate_n_flags)
433 {
434         return !!(rate_n_flags & RATE_MCS_ANT_A_MSK) +
435                !!(rate_n_flags & RATE_MCS_ANT_B_MSK) +
436                !!(rate_n_flags & RATE_MCS_ANT_C_MSK);
437 }
438
439 /**
440  * rs_collect_tx_data - Update the success/failure sliding window
441  *
442  * We keep a sliding window of the last 62 packets transmitted
443  * at this rate.  window->data contains the bitmask of successful
444  * packets.
445  */
446 static int rs_collect_tx_data(struct iwl_rate_scale_data *windows,
447                               int scale_index, s32 tpt, int retries,
448                               int successes)
449 {
450         struct iwl_rate_scale_data *window = NULL;
451         static const u64 mask = (((u64)1) << (IWL_RATE_MAX_WINDOW - 1));
452         s32 fail_count;
453
454         if (scale_index < 0 || scale_index >= IWL_RATE_COUNT)
455                 return -EINVAL;
456
457         /* Select data for current tx bit rate */
458         window = &(windows[scale_index]);
459
460         /*
461          * Keep track of only the latest 62 tx frame attempts in this rate's
462          * history window; anything older isn't really relevant any more.
463          * If we have filled up the sliding window, drop the oldest attempt;
464          * if the oldest attempt (highest bit in bitmap) shows "success",
465          * subtract "1" from the success counter (this is the main reason
466          * we keep these bitmaps!).
467          */
468         while (retries > 0) {
469                 if (window->counter >= IWL_RATE_MAX_WINDOW) {
470
471                         /* remove earliest */
472                         window->counter = IWL_RATE_MAX_WINDOW - 1;
473
474                         if (window->data & mask) {
475                                 window->data &= ~mask;
476                                 window->success_counter--;
477                         }
478                 }
479
480                 /* Increment frames-attempted counter */
481                 window->counter++;
482
483                 /* Shift bitmap by one frame (throw away oldest history),
484                  * OR in "1", and increment "success" if this
485                  * frame was successful. */
486                 window->data <<= 1;
487                 if (successes > 0) {
488                         window->success_counter++;
489                         window->data |= 0x1;
490                         successes--;
491                 }
492
493                 retries--;
494         }
495
496         /* Calculate current success ratio, avoid divide-by-0! */
497         if (window->counter > 0)
498                 window->success_ratio = 128 * (100 * window->success_counter)
499                                         / window->counter;
500         else
501                 window->success_ratio = IWL_INVALID_VALUE;
502
503         fail_count = window->counter - window->success_counter;
504
505         /* Calculate average throughput, if we have enough history. */
506         if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
507             (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
508                 window->average_tpt = (window->success_ratio * tpt + 64) / 128;
509         else
510                 window->average_tpt = IWL_INVALID_VALUE;
511
512         /* Tag this window as having been updated */
513         window->stamp = jiffies;
514
515         return 0;
516 }
517
518 /*
519  * Fill uCode API rate_n_flags field, based on "search" or "active" table.
520  */
521 /* FIXME:RS:remove this function and put the flags statically in the table */
522 static u32 rate_n_flags_from_tbl(struct iwl_priv *priv,
523                                  struct iwl_scale_tbl_info *tbl,
524                                  int index, u8 use_green)
525 {
526         u32 rate_n_flags = 0;
527
528         if (is_legacy(tbl->lq_type)) {
529                 rate_n_flags = iwl_rates[index].plcp;
530                 if (index >= IWL_FIRST_CCK_RATE && index <= IWL_LAST_CCK_RATE)
531                         rate_n_flags |= RATE_MCS_CCK_MSK;
532
533         } else if (is_Ht(tbl->lq_type)) {
534                 if (index > IWL_LAST_OFDM_RATE) {
535                         IWL_ERR(priv, "Invalid HT rate index %d\n", index);
536                         index = IWL_LAST_OFDM_RATE;
537                 }
538                 rate_n_flags = RATE_MCS_HT_MSK;
539
540                 if (is_siso(tbl->lq_type))
541                         rate_n_flags |= iwl_rates[index].plcp_siso;
542                 else if (is_mimo2(tbl->lq_type))
543                         rate_n_flags |= iwl_rates[index].plcp_mimo2;
544                 else
545                         rate_n_flags |= iwl_rates[index].plcp_mimo3;
546         } else {
547                 IWL_ERR(priv, "Invalid tbl->lq_type %d\n", tbl->lq_type);
548         }
549
550         rate_n_flags |= ((tbl->ant_type << RATE_MCS_ANT_POS) &
551                                                      RATE_MCS_ANT_ABC_MSK);
552
553         if (is_Ht(tbl->lq_type)) {
554                 if (tbl->is_ht40) {
555                         if (tbl->is_dup)
556                                 rate_n_flags |= RATE_MCS_DUP_MSK;
557                         else
558                                 rate_n_flags |= RATE_MCS_HT40_MSK;
559                 }
560                 if (tbl->is_SGI)
561                         rate_n_flags |= RATE_MCS_SGI_MSK;
562
563                 if (use_green) {
564                         rate_n_flags |= RATE_MCS_GF_MSK;
565                         if (is_siso(tbl->lq_type) && tbl->is_SGI) {
566                                 rate_n_flags &= ~RATE_MCS_SGI_MSK;
567                                 IWL_ERR(priv, "GF was set with SGI:SISO\n");
568                         }
569                 }
570         }
571         return rate_n_flags;
572 }
573
574 /*
575  * Interpret uCode API's rate_n_flags format,
576  * fill "search" or "active" tx mode table.
577  */
578 static int rs_get_tbl_info_from_mcs(const u32 rate_n_flags,
579                                     enum ieee80211_band band,
580                                     struct iwl_scale_tbl_info *tbl,
581                                     int *rate_idx)
582 {
583         u32 ant_msk = (rate_n_flags & RATE_MCS_ANT_ABC_MSK);
584         u8 num_of_ant = get_num_of_ant_from_rate(rate_n_flags);
585         u8 mcs;
586
587         *rate_idx = iwl_hwrate_to_plcp_idx(rate_n_flags);
588
589         if (*rate_idx  == IWL_RATE_INVALID) {
590                 *rate_idx = -1;
591                 return -EINVAL;
592         }
593         tbl->is_SGI = 0;        /* default legacy setup */
594         tbl->is_ht40 = 0;
595         tbl->is_dup = 0;
596         tbl->ant_type = (ant_msk >> RATE_MCS_ANT_POS);
597         tbl->lq_type = LQ_NONE;
598         tbl->max_search = IWL_MAX_SEARCH;
599
600         /* legacy rate format */
601         if (!(rate_n_flags & RATE_MCS_HT_MSK)) {
602                 if (num_of_ant == 1) {
603                         if (band == IEEE80211_BAND_5GHZ)
604                                 tbl->lq_type = LQ_A;
605                         else
606                                 tbl->lq_type = LQ_G;
607                 }
608         /* HT rate format */
609         } else {
610                 if (rate_n_flags & RATE_MCS_SGI_MSK)
611                         tbl->is_SGI = 1;
612
613                 if ((rate_n_flags & RATE_MCS_HT40_MSK) ||
614                     (rate_n_flags & RATE_MCS_DUP_MSK))
615                         tbl->is_ht40 = 1;
616
617                 if (rate_n_flags & RATE_MCS_DUP_MSK)
618                         tbl->is_dup = 1;
619
620                 mcs = rs_extract_rate(rate_n_flags);
621
622                 /* SISO */
623                 if (mcs <= IWL_RATE_SISO_60M_PLCP) {
624                         if (num_of_ant == 1)
625                                 tbl->lq_type = LQ_SISO; /*else NONE*/
626                 /* MIMO2 */
627                 } else if (mcs <= IWL_RATE_MIMO2_60M_PLCP) {
628                         if (num_of_ant == 2)
629                                 tbl->lq_type = LQ_MIMO2;
630                 /* MIMO3 */
631                 } else {
632                         if (num_of_ant == 3) {
633                                 tbl->max_search = IWL_MAX_11N_MIMO3_SEARCH;
634                                 tbl->lq_type = LQ_MIMO3;
635                         }
636                 }
637         }
638         return 0;
639 }
640
641 /* switch to another antenna/antennas and return 1 */
642 /* if no other valid antenna found, return 0 */
643 static int rs_toggle_antenna(u32 valid_ant, u32 *rate_n_flags,
644                              struct iwl_scale_tbl_info *tbl)
645 {
646         u8 new_ant_type;
647
648         if (!tbl->ant_type || tbl->ant_type > ANT_ABC)
649                 return 0;
650
651         if (!rs_is_valid_ant(valid_ant, tbl->ant_type))
652                 return 0;
653
654         new_ant_type = ant_toggle_lookup[tbl->ant_type];
655
656         while ((new_ant_type != tbl->ant_type) &&
657                !rs_is_valid_ant(valid_ant, new_ant_type))
658                 new_ant_type = ant_toggle_lookup[new_ant_type];
659
660         if (new_ant_type == tbl->ant_type)
661                 return 0;
662
663         tbl->ant_type = new_ant_type;
664         *rate_n_flags &= ~RATE_MCS_ANT_ABC_MSK;
665         *rate_n_flags |= new_ant_type << RATE_MCS_ANT_POS;
666         return 1;
667 }
668
669 /**
670  * Green-field mode is valid if the station supports it and
671  * there are no non-GF stations present in the BSS.
672  */
673 static inline u8 rs_use_green(struct ieee80211_sta *sta,
674                               struct iwl_ht_config *ht_conf)
675 {
676         return (sta->ht_cap.cap & IEEE80211_HT_CAP_GRN_FLD) &&
677                 !(ht_conf->non_GF_STA_present);
678 }
679
680 /**
681  * rs_get_supported_rates - get the available rates
682  *
683  * if management frame or broadcast frame only return
684  * basic available rates.
685  *
686  */
687 static u16 rs_get_supported_rates(struct iwl_lq_sta *lq_sta,
688                                   struct ieee80211_hdr *hdr,
689                                   enum iwl_table_type rate_type)
690 {
691         if (hdr && is_multicast_ether_addr(hdr->addr1) &&
692             lq_sta->active_rate_basic)
693                 return lq_sta->active_rate_basic;
694
695         if (is_legacy(rate_type)) {
696                 return lq_sta->active_legacy_rate;
697         } else {
698                 if (is_siso(rate_type))
699                         return lq_sta->active_siso_rate;
700                 else if (is_mimo2(rate_type))
701                         return lq_sta->active_mimo2_rate;
702                 else
703                         return lq_sta->active_mimo3_rate;
704         }
705 }
706
707 static u16 rs_get_adjacent_rate(struct iwl_priv *priv, u8 index, u16 rate_mask,
708                                 int rate_type)
709 {
710         u8 high = IWL_RATE_INVALID;
711         u8 low = IWL_RATE_INVALID;
712
713         /* 802.11A or ht walks to the next literal adjacent rate in
714          * the rate table */
715         if (is_a_band(rate_type) || !is_legacy(rate_type)) {
716                 int i;
717                 u32 mask;
718
719                 /* Find the previous rate that is in the rate mask */
720                 i = index - 1;
721                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
722                         if (rate_mask & mask) {
723                                 low = i;
724                                 break;
725                         }
726                 }
727
728                 /* Find the next rate that is in the rate mask */
729                 i = index + 1;
730                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
731                         if (rate_mask & mask) {
732                                 high = i;
733                                 break;
734                         }
735                 }
736
737                 return (high << 8) | low;
738         }
739
740         low = index;
741         while (low != IWL_RATE_INVALID) {
742                 low = iwl_rates[low].prev_rs;
743                 if (low == IWL_RATE_INVALID)
744                         break;
745                 if (rate_mask & (1 << low))
746                         break;
747                 IWL_DEBUG_RATE(priv, "Skipping masked lower rate: %d\n", low);
748         }
749
750         high = index;
751         while (high != IWL_RATE_INVALID) {
752                 high = iwl_rates[high].next_rs;
753                 if (high == IWL_RATE_INVALID)
754                         break;
755                 if (rate_mask & (1 << high))
756                         break;
757                 IWL_DEBUG_RATE(priv, "Skipping masked higher rate: %d\n", high);
758         }
759
760         return (high << 8) | low;
761 }
762
763 static u32 rs_get_lower_rate(struct iwl_lq_sta *lq_sta,
764                              struct iwl_scale_tbl_info *tbl,
765                              u8 scale_index, u8 ht_possible)
766 {
767         s32 low;
768         u16 rate_mask;
769         u16 high_low;
770         u8 switch_to_legacy = 0;
771         u8 is_green = lq_sta->is_green;
772         struct iwl_priv *priv = lq_sta->drv;
773
774         /* check if we need to switch from HT to legacy rates.
775          * assumption is that mandatory rates (1Mbps or 6Mbps)
776          * are always supported (spec demand) */
777         if (!is_legacy(tbl->lq_type) && (!ht_possible || !scale_index)) {
778                 switch_to_legacy = 1;
779                 scale_index = rs_ht_to_legacy[scale_index];
780                 if (lq_sta->band == IEEE80211_BAND_5GHZ)
781                         tbl->lq_type = LQ_A;
782                 else
783                         tbl->lq_type = LQ_G;
784
785                 if (num_of_ant(tbl->ant_type) > 1)
786                         tbl->ant_type =
787                                 first_antenna(priv->hw_params.valid_tx_ant);
788
789                 tbl->is_ht40 = 0;
790                 tbl->is_SGI = 0;
791                 tbl->max_search = IWL_MAX_SEARCH;
792         }
793
794         rate_mask = rs_get_supported_rates(lq_sta, NULL, tbl->lq_type);
795
796         /* Mask with station rate restriction */
797         if (is_legacy(tbl->lq_type)) {
798                 /* supp_rates has no CCK bits in A mode */
799                 if (lq_sta->band == IEEE80211_BAND_5GHZ)
800                         rate_mask  = (u16)(rate_mask &
801                            (lq_sta->supp_rates << IWL_FIRST_OFDM_RATE));
802                 else
803                         rate_mask = (u16)(rate_mask & lq_sta->supp_rates);
804         }
805
806         /* If we switched from HT to legacy, check current rate */
807         if (switch_to_legacy && (rate_mask & (1 << scale_index))) {
808                 low = scale_index;
809                 goto out;
810         }
811
812         high_low = rs_get_adjacent_rate(lq_sta->drv, scale_index, rate_mask,
813                                         tbl->lq_type);
814         low = high_low & 0xff;
815
816         if (low == IWL_RATE_INVALID)
817                 low = scale_index;
818
819 out:
820         return rate_n_flags_from_tbl(lq_sta->drv, tbl, low, is_green);
821 }
822
823 /*
824  * mac80211 sends us Tx status
825  */
826 static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband,
827                          struct ieee80211_sta *sta, void *priv_sta,
828                          struct sk_buff *skb)
829 {
830         int status;
831         u8 retries;
832         int rs_index, mac_index, index = 0;
833         struct iwl_lq_sta *lq_sta = priv_sta;
834         struct iwl_link_quality_cmd *table;
835         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
836         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
837         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
838         struct iwl_rate_scale_data *window = NULL;
839         struct iwl_rate_scale_data *search_win = NULL;
840         enum mac80211_rate_control_flags mac_flags;
841         u32 tx_rate;
842         struct iwl_scale_tbl_info tbl_type;
843         struct iwl_scale_tbl_info *curr_tbl, *search_tbl;
844         u8 active_index = 0;
845         s32 tpt = 0;
846
847         IWL_DEBUG_RATE_LIMIT(priv, "get frame ack response, update rate scale window\n");
848
849         if (!ieee80211_is_data(hdr->frame_control) ||
850             info->flags & IEEE80211_TX_CTL_NO_ACK)
851                 return;
852
853         /* This packet was aggregated but doesn't carry rate scale info */
854         if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
855             !(info->flags & IEEE80211_TX_STAT_AMPDU))
856                 return;
857
858         if (info->flags & IEEE80211_TX_STAT_AMPDU)
859                 retries = 0;
860         else
861                 retries = info->status.rates[0].count - 1;
862
863         if (retries > 15)
864                 retries = 15;
865
866         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
867             !lq_sta->ibss_sta_added)
868                 goto out;
869
870         table = &lq_sta->lq;
871         active_index = lq_sta->active_tbl;
872
873         curr_tbl = &(lq_sta->lq_info[active_index]);
874         search_tbl = &(lq_sta->lq_info[(1 - active_index)]);
875         window = (struct iwl_rate_scale_data *)&(curr_tbl->win[0]);
876         search_win = (struct iwl_rate_scale_data *)&(search_tbl->win[0]);
877
878         /*
879          * Ignore this Tx frame response if its initial rate doesn't match
880          * that of latest Link Quality command.  There may be stragglers
881          * from a previous Link Quality command, but we're no longer interested
882          * in those; they're either from the "active" mode while we're trying
883          * to check "search" mode, or a prior "search" mode after we've moved
884          * to a new "search" mode (which might become the new "active" mode).
885          */
886         tx_rate = le32_to_cpu(table->rs_table[0].rate_n_flags);
887         rs_get_tbl_info_from_mcs(tx_rate, priv->band, &tbl_type, &rs_index);
888         if (priv->band == IEEE80211_BAND_5GHZ)
889                 rs_index -= IWL_FIRST_OFDM_RATE;
890         mac_flags = info->status.rates[0].flags;
891         mac_index = info->status.rates[0].idx;
892         /* For HT packets, map MCS to PLCP */
893         if (mac_flags & IEEE80211_TX_RC_MCS) {
894                 mac_index &= RATE_MCS_CODE_MSK; /* Remove # of streams */
895                 if (mac_index >= (IWL_RATE_9M_INDEX - IWL_FIRST_OFDM_RATE))
896                         mac_index++;
897                 /*
898                  * mac80211 HT index is always zero-indexed; we need to move
899                  * HT OFDM rates after CCK rates in 2.4 GHz band
900                  */
901                 if (priv->band == IEEE80211_BAND_2GHZ)
902                         mac_index += IWL_FIRST_OFDM_RATE;
903         }
904
905         if ((mac_index < 0) ||
906             (tbl_type.is_SGI != !!(mac_flags & IEEE80211_TX_RC_SHORT_GI)) ||
907             (tbl_type.is_ht40 != !!(mac_flags & IEEE80211_TX_RC_40_MHZ_WIDTH)) ||
908             (tbl_type.is_dup != !!(mac_flags & IEEE80211_TX_RC_DUP_DATA)) ||
909             (tbl_type.ant_type != info->antenna_sel_tx) ||
910             (!!(tx_rate & RATE_MCS_HT_MSK) != !!(mac_flags & IEEE80211_TX_RC_MCS)) ||
911             (!!(tx_rate & RATE_MCS_GF_MSK) != !!(mac_flags & IEEE80211_TX_RC_GREEN_FIELD)) ||
912             (rs_index != mac_index)) {
913                 IWL_DEBUG_RATE(priv, "initial rate %d does not match %d (0x%x)\n", mac_index, rs_index, tx_rate);
914                 /* the last LQ command could failed so the LQ in ucode not
915                  * the same in driver sync up
916                  */
917                 lq_sta->missed_rate_counter++;
918                 if (lq_sta->missed_rate_counter > IWL_MISSED_RATE_MAX) {
919                         lq_sta->missed_rate_counter = 0;
920                         iwl_send_lq_cmd(priv, &lq_sta->lq, CMD_ASYNC);
921                 }
922                 goto out;
923         }
924
925         lq_sta->missed_rate_counter = 0;
926         /* Update frame history window with "failure" for each Tx retry. */
927         while (retries) {
928                 /* Look up the rate and other info used for each tx attempt.
929                  * Each tx attempt steps one entry deeper in the rate table. */
930                 tx_rate = le32_to_cpu(table->rs_table[index].rate_n_flags);
931                 rs_get_tbl_info_from_mcs(tx_rate, priv->band,
932                                           &tbl_type, &rs_index);
933
934                 /* If type matches "search" table,
935                  * add failure to "search" history */
936                 if ((tbl_type.lq_type == search_tbl->lq_type) &&
937                     (tbl_type.ant_type == search_tbl->ant_type) &&
938                     (tbl_type.is_SGI == search_tbl->is_SGI)) {
939                         if (search_tbl->expected_tpt)
940                                 tpt = search_tbl->expected_tpt[rs_index];
941                         else
942                                 tpt = 0;
943                         rs_collect_tx_data(search_win, rs_index, tpt, 1, 0);
944
945                 /* Else if type matches "current/active" table,
946                  * add failure to "current/active" history */
947                 } else if ((tbl_type.lq_type == curr_tbl->lq_type) &&
948                            (tbl_type.ant_type == curr_tbl->ant_type) &&
949                            (tbl_type.is_SGI == curr_tbl->is_SGI)) {
950                         if (curr_tbl->expected_tpt)
951                                 tpt = curr_tbl->expected_tpt[rs_index];
952                         else
953                                 tpt = 0;
954                         rs_collect_tx_data(window, rs_index, tpt, 1, 0);
955                 }
956
957                 /* If not searching for a new mode, increment failed counter
958                  * ... this helps determine when to start searching again */
959                 if (lq_sta->stay_in_tbl)
960                         lq_sta->total_failed++;
961                 --retries;
962                 index++;
963
964         }
965
966         /*
967          * Find (by rate) the history window to update with final Tx attempt;
968          * if Tx was successful first try, use original rate,
969          * else look up the rate that was, finally, successful.
970          */
971         tx_rate = le32_to_cpu(table->rs_table[index].rate_n_flags);
972         lq_sta->last_rate_n_flags = tx_rate;
973         rs_get_tbl_info_from_mcs(tx_rate, priv->band, &tbl_type, &rs_index);
974
975         /* Update frame history window with "success" if Tx got ACKed ... */
976         status = !!(info->flags & IEEE80211_TX_STAT_ACK);
977
978         /* If type matches "search" table,
979          * add final tx status to "search" history */
980         if ((tbl_type.lq_type == search_tbl->lq_type) &&
981             (tbl_type.ant_type == search_tbl->ant_type) &&
982             (tbl_type.is_SGI == search_tbl->is_SGI)) {
983                 if (search_tbl->expected_tpt)
984                         tpt = search_tbl->expected_tpt[rs_index];
985                 else
986                         tpt = 0;
987                 if (info->flags & IEEE80211_TX_STAT_AMPDU)
988                         rs_collect_tx_data(search_win, rs_index, tpt,
989                                            info->status.ampdu_ack_len,
990                                            info->status.ampdu_ack_map);
991                 else
992                         rs_collect_tx_data(search_win, rs_index, tpt,
993                                            1, status);
994         /* Else if type matches "current/active" table,
995          * add final tx status to "current/active" history */
996         } else if ((tbl_type.lq_type == curr_tbl->lq_type) &&
997                    (tbl_type.ant_type == curr_tbl->ant_type) &&
998                    (tbl_type.is_SGI == curr_tbl->is_SGI)) {
999                 if (curr_tbl->expected_tpt)
1000                         tpt = curr_tbl->expected_tpt[rs_index];
1001                 else
1002                         tpt = 0;
1003                 if (info->flags & IEEE80211_TX_STAT_AMPDU)
1004                         rs_collect_tx_data(window, rs_index, tpt,
1005                                            info->status.ampdu_ack_len,
1006                                            info->status.ampdu_ack_map);
1007                 else
1008                         rs_collect_tx_data(window, rs_index, tpt,
1009                                            1, status);
1010         }
1011
1012         /* If not searching for new mode, increment success/failed counter
1013          * ... these help determine when to start searching again */
1014         if (lq_sta->stay_in_tbl) {
1015                 if (info->flags & IEEE80211_TX_STAT_AMPDU) {
1016                         lq_sta->total_success += info->status.ampdu_ack_map;
1017                         lq_sta->total_failed +=
1018                              (info->status.ampdu_ack_len - info->status.ampdu_ack_map);
1019                 } else {
1020                         if (status)
1021                                 lq_sta->total_success++;
1022                         else
1023                                 lq_sta->total_failed++;
1024                 }
1025         }
1026
1027         /* See if there's a better rate or modulation mode to try. */
1028         if (sta && sta->supp_rates[sband->band])
1029                 rs_rate_scale_perform(priv, skb, sta, lq_sta);
1030 out:
1031         return;
1032 }
1033
1034 /*
1035  * Begin a period of staying with a selected modulation mode.
1036  * Set "stay_in_tbl" flag to prevent any mode switches.
1037  * Set frame tx success limits according to legacy vs. high-throughput,
1038  * and reset overall (spanning all rates) tx success history statistics.
1039  * These control how long we stay using same modulation mode before
1040  * searching for a new mode.
1041  */
1042 static void rs_set_stay_in_table(struct iwl_priv *priv, u8 is_legacy,
1043                                  struct iwl_lq_sta *lq_sta)
1044 {
1045         IWL_DEBUG_RATE(priv, "we are staying in the same table\n");
1046         lq_sta->stay_in_tbl = 1;        /* only place this gets set */
1047         if (is_legacy) {
1048                 lq_sta->table_count_limit = IWL_LEGACY_TABLE_COUNT;
1049                 lq_sta->max_failure_limit = IWL_LEGACY_FAILURE_LIMIT;
1050                 lq_sta->max_success_limit = IWL_LEGACY_SUCCESS_LIMIT;
1051         } else {
1052                 lq_sta->table_count_limit = IWL_NONE_LEGACY_TABLE_COUNT;
1053                 lq_sta->max_failure_limit = IWL_NONE_LEGACY_FAILURE_LIMIT;
1054                 lq_sta->max_success_limit = IWL_NONE_LEGACY_SUCCESS_LIMIT;
1055         }
1056         lq_sta->table_count = 0;
1057         lq_sta->total_failed = 0;
1058         lq_sta->total_success = 0;
1059         lq_sta->flush_timer = jiffies;
1060         lq_sta->action_counter = 0;
1061 }
1062
1063 /*
1064  * Find correct throughput table for given mode of modulation
1065  */
1066 static void rs_set_expected_tpt_table(struct iwl_lq_sta *lq_sta,
1067                                       struct iwl_scale_tbl_info *tbl)
1068 {
1069         if (is_legacy(tbl->lq_type)) {
1070                 if (!is_a_band(tbl->lq_type))
1071                         tbl->expected_tpt = expected_tpt_G;
1072                 else
1073                         tbl->expected_tpt = expected_tpt_A;
1074         } else if (is_siso(tbl->lq_type)) {
1075                 if (tbl->is_ht40 && !lq_sta->is_dup)
1076                         if (tbl->is_SGI)
1077                                 tbl->expected_tpt = expected_tpt_siso40MHzSGI;
1078                         else
1079                                 tbl->expected_tpt = expected_tpt_siso40MHz;
1080                 else if (tbl->is_SGI)
1081                         tbl->expected_tpt = expected_tpt_siso20MHzSGI;
1082                 else
1083                         tbl->expected_tpt = expected_tpt_siso20MHz;
1084         } else if (is_mimo2(tbl->lq_type)) {
1085                 if (tbl->is_ht40 && !lq_sta->is_dup)
1086                         if (tbl->is_SGI)
1087                                 tbl->expected_tpt = expected_tpt_mimo2_40MHzSGI;
1088                         else
1089                                 tbl->expected_tpt = expected_tpt_mimo2_40MHz;
1090                 else if (tbl->is_SGI)
1091                         tbl->expected_tpt = expected_tpt_mimo2_20MHzSGI;
1092                 else
1093                         tbl->expected_tpt = expected_tpt_mimo2_20MHz;
1094         } else if (is_mimo3(tbl->lq_type)) {
1095                 if (tbl->is_ht40 && !lq_sta->is_dup)
1096                         if (tbl->is_SGI)
1097                                 tbl->expected_tpt = expected_tpt_mimo3_40MHzSGI;
1098                         else
1099                                 tbl->expected_tpt = expected_tpt_mimo3_40MHz;
1100                 else if (tbl->is_SGI)
1101                         tbl->expected_tpt = expected_tpt_mimo3_20MHzSGI;
1102                 else
1103                         tbl->expected_tpt = expected_tpt_mimo3_20MHz;
1104         } else
1105                 tbl->expected_tpt = expected_tpt_G;
1106 }
1107
1108 /*
1109  * Find starting rate for new "search" high-throughput mode of modulation.
1110  * Goal is to find lowest expected rate (under perfect conditions) that is
1111  * above the current measured throughput of "active" mode, to give new mode
1112  * a fair chance to prove itself without too many challenges.
1113  *
1114  * This gets called when transitioning to more aggressive modulation
1115  * (i.e. legacy to SISO or MIMO, or SISO to MIMO), as well as less aggressive
1116  * (i.e. MIMO to SISO).  When moving to MIMO, bit rate will typically need
1117  * to decrease to match "active" throughput.  When moving from MIMO to SISO,
1118  * bit rate will typically need to increase, but not if performance was bad.
1119  */
1120 static s32 rs_get_best_rate(struct iwl_priv *priv,
1121                             struct iwl_lq_sta *lq_sta,
1122                             struct iwl_scale_tbl_info *tbl,     /* "search" */
1123                             u16 rate_mask, s8 index)
1124 {
1125         /* "active" values */
1126         struct iwl_scale_tbl_info *active_tbl =
1127             &(lq_sta->lq_info[lq_sta->active_tbl]);
1128         s32 active_sr = active_tbl->win[index].success_ratio;
1129         s32 active_tpt = active_tbl->expected_tpt[index];
1130
1131         /* expected "search" throughput */
1132         s32 *tpt_tbl = tbl->expected_tpt;
1133
1134         s32 new_rate, high, low, start_hi;
1135         u16 high_low;
1136         s8 rate = index;
1137
1138         new_rate = high = low = start_hi = IWL_RATE_INVALID;
1139
1140         for (; ;) {
1141                 high_low = rs_get_adjacent_rate(priv, rate, rate_mask,
1142                                                 tbl->lq_type);
1143
1144                 low = high_low & 0xff;
1145                 high = (high_low >> 8) & 0xff;
1146
1147                 /*
1148                  * Lower the "search" bit rate, to give new "search" mode
1149                  * approximately the same throughput as "active" if:
1150                  *
1151                  * 1) "Active" mode has been working modestly well (but not
1152                  *    great), and expected "search" throughput (under perfect
1153                  *    conditions) at candidate rate is above the actual
1154                  *    measured "active" throughput (but less than expected
1155                  *    "active" throughput under perfect conditions).
1156                  * OR
1157                  * 2) "Active" mode has been working perfectly or very well
1158                  *    and expected "search" throughput (under perfect
1159                  *    conditions) at candidate rate is above expected
1160                  *    "active" throughput (under perfect conditions).
1161                  */
1162                 if ((((100 * tpt_tbl[rate]) > lq_sta->last_tpt) &&
1163                      ((active_sr > IWL_RATE_DECREASE_TH) &&
1164                       (active_sr <= IWL_RATE_HIGH_TH) &&
1165                       (tpt_tbl[rate] <= active_tpt))) ||
1166                     ((active_sr >= IWL_RATE_SCALE_SWITCH) &&
1167                      (tpt_tbl[rate] > active_tpt))) {
1168
1169                         /* (2nd or later pass)
1170                          * If we've already tried to raise the rate, and are
1171                          * now trying to lower it, use the higher rate. */
1172                         if (start_hi != IWL_RATE_INVALID) {
1173                                 new_rate = start_hi;
1174                                 break;
1175                         }
1176
1177                         new_rate = rate;
1178
1179                         /* Loop again with lower rate */
1180                         if (low != IWL_RATE_INVALID)
1181                                 rate = low;
1182
1183                         /* Lower rate not available, use the original */
1184                         else
1185                                 break;
1186
1187                 /* Else try to raise the "search" rate to match "active" */
1188                 } else {
1189                         /* (2nd or later pass)
1190                          * If we've already tried to lower the rate, and are
1191                          * now trying to raise it, use the lower rate. */
1192                         if (new_rate != IWL_RATE_INVALID)
1193                                 break;
1194
1195                         /* Loop again with higher rate */
1196                         else if (high != IWL_RATE_INVALID) {
1197                                 start_hi = high;
1198                                 rate = high;
1199
1200                         /* Higher rate not available, use the original */
1201                         } else {
1202                                 new_rate = rate;
1203                                 break;
1204                         }
1205                 }
1206         }
1207
1208         return new_rate;
1209 }
1210
1211 /*
1212  * Set up search table for MIMO2
1213  */
1214 static int rs_switch_to_mimo2(struct iwl_priv *priv,
1215                              struct iwl_lq_sta *lq_sta,
1216                              struct ieee80211_conf *conf,
1217                              struct ieee80211_sta *sta,
1218                              struct iwl_scale_tbl_info *tbl, int index)
1219 {
1220         u16 rate_mask;
1221         s32 rate;
1222         s8 is_green = lq_sta->is_green;
1223
1224         if (!conf_is_ht(conf) || !sta->ht_cap.ht_supported)
1225                 return -1;
1226
1227         if (((sta->ht_cap.cap & IEEE80211_HT_CAP_SM_PS) >> 2)
1228                                                 == WLAN_HT_CAP_SM_PS_STATIC)
1229                 return -1;
1230
1231         /* Need both Tx chains/antennas to support MIMO */
1232         if (priv->hw_params.tx_chains_num < 2)
1233                 return -1;
1234
1235         IWL_DEBUG_RATE(priv, "LQ: try to switch to MIMO2\n");
1236
1237         tbl->lq_type = LQ_MIMO2;
1238         tbl->is_dup = lq_sta->is_dup;
1239         tbl->action = 0;
1240         tbl->max_search = IWL_MAX_SEARCH;
1241         rate_mask = lq_sta->active_mimo2_rate;
1242
1243         if (iwl_is_ht40_tx_allowed(priv, &sta->ht_cap))
1244                 tbl->is_ht40 = 1;
1245         else
1246                 tbl->is_ht40 = 0;
1247
1248         rs_set_expected_tpt_table(lq_sta, tbl);
1249
1250         rate = rs_get_best_rate(priv, lq_sta, tbl, rate_mask, index);
1251
1252         IWL_DEBUG_RATE(priv, "LQ: MIMO2 best rate %d mask %X\n", rate, rate_mask);
1253         if ((rate == IWL_RATE_INVALID) || !((1 << rate) & rate_mask)) {
1254                 IWL_DEBUG_RATE(priv, "Can't switch with index %d rate mask %x\n",
1255                                                 rate, rate_mask);
1256                 return -1;
1257         }
1258         tbl->current_rate = rate_n_flags_from_tbl(priv, tbl, rate, is_green);
1259
1260         IWL_DEBUG_RATE(priv, "LQ: Switch to new mcs %X index is green %X\n",
1261                      tbl->current_rate, is_green);
1262         return 0;
1263 }
1264
1265 /*
1266  * Set up search table for MIMO3
1267  */
1268 static int rs_switch_to_mimo3(struct iwl_priv *priv,
1269                              struct iwl_lq_sta *lq_sta,
1270                              struct ieee80211_conf *conf,
1271                              struct ieee80211_sta *sta,
1272                              struct iwl_scale_tbl_info *tbl, int index)
1273 {
1274         u16 rate_mask;
1275         s32 rate;
1276         s8 is_green = lq_sta->is_green;
1277
1278         if (!conf_is_ht(conf) || !sta->ht_cap.ht_supported)
1279                 return -1;
1280
1281         if (((sta->ht_cap.cap & IEEE80211_HT_CAP_SM_PS) >> 2)
1282                                                 == WLAN_HT_CAP_SM_PS_STATIC)
1283                 return -1;
1284
1285         /* Need both Tx chains/antennas to support MIMO */
1286         if (priv->hw_params.tx_chains_num < 3)
1287                 return -1;
1288
1289         IWL_DEBUG_RATE(priv, "LQ: try to switch to MIMO3\n");
1290
1291         tbl->lq_type = LQ_MIMO3;
1292         tbl->is_dup = lq_sta->is_dup;
1293         tbl->action = 0;
1294         tbl->max_search = IWL_MAX_11N_MIMO3_SEARCH;
1295         rate_mask = lq_sta->active_mimo3_rate;
1296
1297         if (iwl_is_ht40_tx_allowed(priv, &sta->ht_cap))
1298                 tbl->is_ht40 = 1;
1299         else
1300                 tbl->is_ht40 = 0;
1301
1302         rs_set_expected_tpt_table(lq_sta, tbl);
1303
1304         rate = rs_get_best_rate(priv, lq_sta, tbl, rate_mask, index);
1305
1306         IWL_DEBUG_RATE(priv, "LQ: MIMO3 best rate %d mask %X\n",
1307                 rate, rate_mask);
1308         if ((rate == IWL_RATE_INVALID) || !((1 << rate) & rate_mask)) {
1309                 IWL_DEBUG_RATE(priv, "Can't switch with index %d rate mask %x\n",
1310                                                 rate, rate_mask);
1311                 return -1;
1312         }
1313         tbl->current_rate = rate_n_flags_from_tbl(priv, tbl, rate, is_green);
1314
1315         IWL_DEBUG_RATE(priv, "LQ: Switch to new mcs %X index is green %X\n",
1316                      tbl->current_rate, is_green);
1317         return 0;
1318 }
1319
1320 /*
1321  * Set up search table for SISO
1322  */
1323 static int rs_switch_to_siso(struct iwl_priv *priv,
1324                              struct iwl_lq_sta *lq_sta,
1325                              struct ieee80211_conf *conf,
1326                              struct ieee80211_sta *sta,
1327                              struct iwl_scale_tbl_info *tbl, int index)
1328 {
1329         u16 rate_mask;
1330         u8 is_green = lq_sta->is_green;
1331         s32 rate;
1332
1333         if (!conf_is_ht(conf) || !sta->ht_cap.ht_supported)
1334                 return -1;
1335
1336         IWL_DEBUG_RATE(priv, "LQ: try to switch to SISO\n");
1337
1338         tbl->is_dup = lq_sta->is_dup;
1339         tbl->lq_type = LQ_SISO;
1340         tbl->action = 0;
1341         tbl->max_search = IWL_MAX_SEARCH;
1342         rate_mask = lq_sta->active_siso_rate;
1343
1344         if (iwl_is_ht40_tx_allowed(priv, &sta->ht_cap))
1345                 tbl->is_ht40 = 1;
1346         else
1347                 tbl->is_ht40 = 0;
1348
1349         if (is_green)
1350                 tbl->is_SGI = 0; /*11n spec: no SGI in SISO+Greenfield*/
1351
1352         rs_set_expected_tpt_table(lq_sta, tbl);
1353         rate = rs_get_best_rate(priv, lq_sta, tbl, rate_mask, index);
1354
1355         IWL_DEBUG_RATE(priv, "LQ: get best rate %d mask %X\n", rate, rate_mask);
1356         if ((rate == IWL_RATE_INVALID) || !((1 << rate) & rate_mask)) {
1357                 IWL_DEBUG_RATE(priv, "can not switch with index %d rate mask %x\n",
1358                              rate, rate_mask);
1359                 return -1;
1360         }
1361         tbl->current_rate = rate_n_flags_from_tbl(priv, tbl, rate, is_green);
1362         IWL_DEBUG_RATE(priv, "LQ: Switch to new mcs %X index is green %X\n",
1363                      tbl->current_rate, is_green);
1364         return 0;
1365 }
1366
1367 /*
1368  * Try to switch to new modulation mode from legacy
1369  */
1370 static int rs_move_legacy_other(struct iwl_priv *priv,
1371                                 struct iwl_lq_sta *lq_sta,
1372                                 struct ieee80211_conf *conf,
1373                                 struct ieee80211_sta *sta,
1374                                 int index)
1375 {
1376         struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
1377         struct iwl_scale_tbl_info *search_tbl =
1378                                 &(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
1379         struct iwl_rate_scale_data *window = &(tbl->win[index]);
1380         u32 sz = (sizeof(struct iwl_scale_tbl_info) -
1381                   (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
1382         u8 start_action = tbl->action;
1383         u8 valid_tx_ant = priv->hw_params.valid_tx_ant;
1384         u8 tx_chains_num = priv->hw_params.tx_chains_num;
1385         int ret = 0;
1386         u8 update_search_tbl_counter = 0;
1387
1388         if (!iwl_ht_enabled(priv))
1389                 /* stay in Legacy */
1390                 tbl->action = IWL_LEGACY_SWITCH_ANTENNA1;
1391         else if (iwl_tx_ant_restriction(priv) == IWL_ANT_OK_SINGLE &&
1392                    tbl->action > IWL_LEGACY_SWITCH_SISO)
1393                 tbl->action = IWL_LEGACY_SWITCH_SISO;
1394         for (; ;) {
1395                 lq_sta->action_counter++;
1396                 switch (tbl->action) {
1397                 case IWL_LEGACY_SWITCH_ANTENNA1:
1398                 case IWL_LEGACY_SWITCH_ANTENNA2:
1399                         IWL_DEBUG_RATE(priv, "LQ: Legacy toggle Antenna\n");
1400
1401                         if ((tbl->action == IWL_LEGACY_SWITCH_ANTENNA1 &&
1402                                                         tx_chains_num <= 1) ||
1403                             (tbl->action == IWL_LEGACY_SWITCH_ANTENNA2 &&
1404                                                         tx_chains_num <= 2))
1405                                 break;
1406
1407                         /* Don't change antenna if success has been great */
1408                         if (window->success_ratio >= IWL_RS_GOOD_RATIO)
1409                                 break;
1410
1411                         /* Set up search table to try other antenna */
1412                         memcpy(search_tbl, tbl, sz);
1413
1414                         if (rs_toggle_antenna(valid_tx_ant,
1415                                 &search_tbl->current_rate, search_tbl)) {
1416                                 update_search_tbl_counter = 1;
1417                                 rs_set_expected_tpt_table(lq_sta, search_tbl);
1418                                 goto out;
1419                         }
1420                         break;
1421                 case IWL_LEGACY_SWITCH_SISO:
1422                         IWL_DEBUG_RATE(priv, "LQ: Legacy switch to SISO\n");
1423
1424                         /* Set up search table to try SISO */
1425                         memcpy(search_tbl, tbl, sz);
1426                         search_tbl->is_SGI = 0;
1427                         ret = rs_switch_to_siso(priv, lq_sta, conf, sta,
1428                                                  search_tbl, index);
1429                         if (!ret) {
1430                                 lq_sta->action_counter = 0;
1431                                 goto out;
1432                         }
1433
1434                         break;
1435                 case IWL_LEGACY_SWITCH_MIMO2_AB:
1436                 case IWL_LEGACY_SWITCH_MIMO2_AC:
1437                 case IWL_LEGACY_SWITCH_MIMO2_BC:
1438                         IWL_DEBUG_RATE(priv, "LQ: Legacy switch to MIMO2\n");
1439
1440                         /* Set up search table to try MIMO */
1441                         memcpy(search_tbl, tbl, sz);
1442                         search_tbl->is_SGI = 0;
1443
1444                         if (tbl->action == IWL_LEGACY_SWITCH_MIMO2_AB)
1445                                 search_tbl->ant_type = ANT_AB;
1446                         else if (tbl->action == IWL_LEGACY_SWITCH_MIMO2_AC)
1447                                 search_tbl->ant_type = ANT_AC;
1448                         else
1449                                 search_tbl->ant_type = ANT_BC;
1450
1451                         if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
1452                                 break;
1453
1454                         ret = rs_switch_to_mimo2(priv, lq_sta, conf, sta,
1455                                                  search_tbl, index);
1456                         if (!ret) {
1457                                 lq_sta->action_counter = 0;
1458                                 goto out;
1459                         }
1460                         break;
1461
1462                 case IWL_LEGACY_SWITCH_MIMO3_ABC:
1463                         IWL_DEBUG_RATE(priv, "LQ: Legacy switch to MIMO3\n");
1464
1465                         /* Set up search table to try MIMO3 */
1466                         memcpy(search_tbl, tbl, sz);
1467                         search_tbl->is_SGI = 0;
1468
1469                         search_tbl->ant_type = ANT_ABC;
1470
1471                         if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
1472                                 break;
1473
1474                         ret = rs_switch_to_mimo3(priv, lq_sta, conf, sta,
1475                                                  search_tbl, index);
1476                         if (!ret) {
1477                                 lq_sta->action_counter = 0;
1478                                 goto out;
1479                         }
1480                         break;
1481                 }
1482                 tbl->action++;
1483                 if (tbl->action > IWL_LEGACY_SWITCH_MIMO3_ABC)
1484                         tbl->action = IWL_LEGACY_SWITCH_ANTENNA1;
1485
1486                 if (tbl->action == start_action)
1487                         break;
1488
1489         }
1490         search_tbl->lq_type = LQ_NONE;
1491         return 0;
1492
1493 out:
1494         lq_sta->search_better_tbl = 1;
1495         tbl->action++;
1496         if (tbl->action > IWL_LEGACY_SWITCH_MIMO3_ABC)
1497                 tbl->action = IWL_LEGACY_SWITCH_ANTENNA1;
1498         if (update_search_tbl_counter)
1499                 search_tbl->action = tbl->action;
1500         return 0;
1501
1502 }
1503
1504 /*
1505  * Try to switch to new modulation mode from SISO
1506  */
1507 static int rs_move_siso_to_other(struct iwl_priv *priv,
1508                                  struct iwl_lq_sta *lq_sta,
1509                                  struct ieee80211_conf *conf,
1510                                  struct ieee80211_sta *sta, int index)
1511 {
1512         u8 is_green = lq_sta->is_green;
1513         struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
1514         struct iwl_scale_tbl_info *search_tbl =
1515                                 &(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
1516         struct iwl_rate_scale_data *window = &(tbl->win[index]);
1517         struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
1518         u32 sz = (sizeof(struct iwl_scale_tbl_info) -
1519                   (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
1520         u8 start_action = tbl->action;
1521         u8 valid_tx_ant = priv->hw_params.valid_tx_ant;
1522         u8 tx_chains_num = priv->hw_params.tx_chains_num;
1523         u8 update_search_tbl_counter = 0;
1524         int ret;
1525
1526         if (iwl_tx_ant_restriction(priv) == IWL_ANT_OK_SINGLE &&
1527             tbl->action > IWL_SISO_SWITCH_ANTENNA2) {
1528                 /* stay in SISO */
1529                 tbl->action = IWL_SISO_SWITCH_ANTENNA1;
1530         }
1531         for (;;) {
1532                 lq_sta->action_counter++;
1533                 switch (tbl->action) {
1534                 case IWL_SISO_SWITCH_ANTENNA1:
1535                 case IWL_SISO_SWITCH_ANTENNA2:
1536                         IWL_DEBUG_RATE(priv, "LQ: SISO toggle Antenna\n");
1537
1538                         if ((tbl->action == IWL_SISO_SWITCH_ANTENNA1 &&
1539                                                         tx_chains_num <= 1) ||
1540                             (tbl->action == IWL_SISO_SWITCH_ANTENNA2 &&
1541                                                         tx_chains_num <= 2))
1542                                 break;
1543
1544                         if (window->success_ratio >= IWL_RS_GOOD_RATIO)
1545                                 break;
1546
1547                         memcpy(search_tbl, tbl, sz);
1548                         if (rs_toggle_antenna(valid_tx_ant,
1549                                        &search_tbl->current_rate, search_tbl)) {
1550                                 update_search_tbl_counter = 1;
1551                                 goto out;
1552                         }
1553                         break;
1554                 case IWL_SISO_SWITCH_MIMO2_AB:
1555                 case IWL_SISO_SWITCH_MIMO2_AC:
1556                 case IWL_SISO_SWITCH_MIMO2_BC:
1557                         IWL_DEBUG_RATE(priv, "LQ: SISO switch to MIMO2\n");
1558                         memcpy(search_tbl, tbl, sz);
1559                         search_tbl->is_SGI = 0;
1560
1561                         if (tbl->action == IWL_SISO_SWITCH_MIMO2_AB)
1562                                 search_tbl->ant_type = ANT_AB;
1563                         else if (tbl->action == IWL_SISO_SWITCH_MIMO2_AC)
1564                                 search_tbl->ant_type = ANT_AC;
1565                         else
1566                                 search_tbl->ant_type = ANT_BC;
1567
1568                         if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
1569                                 break;
1570
1571                         ret = rs_switch_to_mimo2(priv, lq_sta, conf, sta,
1572                                                  search_tbl, index);
1573                         if (!ret)
1574                                 goto out;
1575                         break;
1576                 case IWL_SISO_SWITCH_GI:
1577                         if (!tbl->is_ht40 && !(ht_cap->cap &
1578                                                 IEEE80211_HT_CAP_SGI_20))
1579                                 break;
1580                         if (tbl->is_ht40 && !(ht_cap->cap &
1581                                                 IEEE80211_HT_CAP_SGI_40))
1582                                 break;
1583
1584                         IWL_DEBUG_RATE(priv, "LQ: SISO toggle SGI/NGI\n");
1585
1586                         memcpy(search_tbl, tbl, sz);
1587                         if (is_green) {
1588                                 if (!tbl->is_SGI)
1589                                         break;
1590                                 else
1591                                         IWL_ERR(priv,
1592                                                 "SGI was set in GF+SISO\n");
1593                         }
1594                         search_tbl->is_SGI = !tbl->is_SGI;
1595                         rs_set_expected_tpt_table(lq_sta, search_tbl);
1596                         if (tbl->is_SGI) {
1597                                 s32 tpt = lq_sta->last_tpt / 100;
1598                                 if (tpt >= search_tbl->expected_tpt[index])
1599                                         break;
1600                         }
1601                         search_tbl->current_rate =
1602                                 rate_n_flags_from_tbl(priv, search_tbl,
1603                                                       index, is_green);
1604                         update_search_tbl_counter = 1;
1605                         goto out;
1606                 case IWL_SISO_SWITCH_MIMO3_ABC:
1607                         IWL_DEBUG_RATE(priv, "LQ: SISO switch to MIMO3\n");
1608                         memcpy(search_tbl, tbl, sz);
1609                         search_tbl->is_SGI = 0;
1610                         search_tbl->ant_type = ANT_ABC;
1611
1612                         if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
1613                                 break;
1614
1615                         ret = rs_switch_to_mimo3(priv, lq_sta, conf, sta,
1616                                                  search_tbl, index);
1617                         if (!ret)
1618                                 goto out;
1619                         break;
1620                 }
1621                 tbl->action++;
1622                 if (tbl->action > IWL_LEGACY_SWITCH_MIMO3_ABC)
1623                         tbl->action = IWL_SISO_SWITCH_ANTENNA1;
1624
1625                 if (tbl->action == start_action)
1626                         break;
1627         }
1628         search_tbl->lq_type = LQ_NONE;
1629         return 0;
1630
1631  out:
1632         lq_sta->search_better_tbl = 1;
1633         tbl->action++;
1634         if (tbl->action > IWL_SISO_SWITCH_MIMO3_ABC)
1635                 tbl->action = IWL_SISO_SWITCH_ANTENNA1;
1636         if (update_search_tbl_counter)
1637                 search_tbl->action = tbl->action;
1638
1639         return 0;
1640 }
1641
1642 /*
1643  * Try to switch to new modulation mode from MIMO2
1644  */
1645 static int rs_move_mimo2_to_other(struct iwl_priv *priv,
1646                                  struct iwl_lq_sta *lq_sta,
1647                                  struct ieee80211_conf *conf,
1648                                  struct ieee80211_sta *sta, int index)
1649 {
1650         s8 is_green = lq_sta->is_green;
1651         struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
1652         struct iwl_scale_tbl_info *search_tbl =
1653                                 &(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
1654         struct iwl_rate_scale_data *window = &(tbl->win[index]);
1655         struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
1656         u32 sz = (sizeof(struct iwl_scale_tbl_info) -
1657                   (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
1658         u8 start_action = tbl->action;
1659         u8 valid_tx_ant = priv->hw_params.valid_tx_ant;
1660         u8 tx_chains_num = priv->hw_params.tx_chains_num;
1661         u8 update_search_tbl_counter = 0;
1662         int ret;
1663
1664         if ((iwl_tx_ant_restriction(priv) == IWL_ANT_OK_SINGLE) &&
1665             (tbl->action < IWL_MIMO2_SWITCH_SISO_A ||
1666              tbl->action > IWL_MIMO2_SWITCH_SISO_C)) {
1667                 /* switch in SISO */
1668                 tbl->action = IWL_MIMO2_SWITCH_SISO_A;
1669         }
1670         for (;;) {
1671                 lq_sta->action_counter++;
1672                 switch (tbl->action) {
1673                 case IWL_MIMO2_SWITCH_ANTENNA1:
1674                 case IWL_MIMO2_SWITCH_ANTENNA2:
1675                         IWL_DEBUG_RATE(priv, "LQ: MIMO2 toggle Antennas\n");
1676
1677                         if (tx_chains_num <= 2)
1678                                 break;
1679
1680                         if (window->success_ratio >= IWL_RS_GOOD_RATIO)
1681                                 break;
1682
1683                         memcpy(search_tbl, tbl, sz);
1684                         if (rs_toggle_antenna(valid_tx_ant,
1685                                        &search_tbl->current_rate, search_tbl)) {
1686                                 update_search_tbl_counter = 1;
1687                                 goto out;
1688                         }
1689                         break;
1690                 case IWL_MIMO2_SWITCH_SISO_A:
1691                 case IWL_MIMO2_SWITCH_SISO_B:
1692                 case IWL_MIMO2_SWITCH_SISO_C:
1693                         IWL_DEBUG_RATE(priv, "LQ: MIMO2 switch to SISO\n");
1694
1695                         /* Set up new search table for SISO */
1696                         memcpy(search_tbl, tbl, sz);
1697
1698                         if (tbl->action == IWL_MIMO2_SWITCH_SISO_A)
1699                                 search_tbl->ant_type = ANT_A;
1700                         else if (tbl->action == IWL_MIMO2_SWITCH_SISO_B)
1701                                 search_tbl->ant_type = ANT_B;
1702                         else
1703                                 search_tbl->ant_type = ANT_C;
1704
1705                         if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
1706                                 break;
1707
1708                         ret = rs_switch_to_siso(priv, lq_sta, conf, sta,
1709                                                  search_tbl, index);
1710                         if (!ret)
1711                                 goto out;
1712
1713                         break;
1714
1715                 case IWL_MIMO2_SWITCH_GI:
1716                         if (!tbl->is_ht40 && !(ht_cap->cap &
1717                                                 IEEE80211_HT_CAP_SGI_20))
1718                                 break;
1719                         if (tbl->is_ht40 && !(ht_cap->cap &
1720                                                 IEEE80211_HT_CAP_SGI_40))
1721                                 break;
1722
1723                         IWL_DEBUG_RATE(priv, "LQ: MIMO2 toggle SGI/NGI\n");
1724
1725                         /* Set up new search table for MIMO2 */
1726                         memcpy(search_tbl, tbl, sz);
1727                         search_tbl->is_SGI = !tbl->is_SGI;
1728                         rs_set_expected_tpt_table(lq_sta, search_tbl);
1729                         /*
1730                          * If active table already uses the fastest possible
1731                          * modulation (dual stream with short guard interval),
1732                          * and it's working well, there's no need to look
1733                          * for a better type of modulation!
1734                          */
1735                         if (tbl->is_SGI) {
1736                                 s32 tpt = lq_sta->last_tpt / 100;
1737                                 if (tpt >= search_tbl->expected_tpt[index])
1738                                         break;
1739                         }
1740                         search_tbl->current_rate =
1741                                 rate_n_flags_from_tbl(priv, search_tbl,
1742                                                       index, is_green);
1743                         update_search_tbl_counter = 1;
1744                         goto out;
1745
1746                 case IWL_MIMO2_SWITCH_MIMO3_ABC:
1747                         IWL_DEBUG_RATE(priv, "LQ: MIMO2 switch to MIMO3\n");
1748                         memcpy(search_tbl, tbl, sz);
1749                         search_tbl->is_SGI = 0;
1750                         search_tbl->ant_type = ANT_ABC;
1751
1752                         if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
1753                                 break;
1754
1755                         ret = rs_switch_to_mimo3(priv, lq_sta, conf, sta,
1756                                                  search_tbl, index);
1757                         if (!ret)
1758                                 goto out;
1759
1760                         break;
1761                 }
1762                 tbl->action++;
1763                 if (tbl->action > IWL_MIMO2_SWITCH_MIMO3_ABC)
1764                         tbl->action = IWL_MIMO2_SWITCH_ANTENNA1;
1765
1766                 if (tbl->action == start_action)
1767                         break;
1768         }
1769         search_tbl->lq_type = LQ_NONE;
1770         return 0;
1771  out:
1772         lq_sta->search_better_tbl = 1;
1773         tbl->action++;
1774         if (tbl->action > IWL_MIMO2_SWITCH_MIMO3_ABC)
1775                 tbl->action = IWL_MIMO2_SWITCH_ANTENNA1;
1776         if (update_search_tbl_counter)
1777                 search_tbl->action = tbl->action;
1778
1779         return 0;
1780
1781 }
1782
1783 /*
1784  * Try to switch to new modulation mode from MIMO3
1785  */
1786 static int rs_move_mimo3_to_other(struct iwl_priv *priv,
1787                                  struct iwl_lq_sta *lq_sta,
1788                                  struct ieee80211_conf *conf,
1789                                  struct ieee80211_sta *sta, int index)
1790 {
1791         s8 is_green = lq_sta->is_green;
1792         struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
1793         struct iwl_scale_tbl_info *search_tbl =
1794                                 &(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
1795         struct iwl_rate_scale_data *window = &(tbl->win[index]);
1796         struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
1797         u32 sz = (sizeof(struct iwl_scale_tbl_info) -
1798                   (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
1799         u8 start_action = tbl->action;
1800         u8 valid_tx_ant = priv->hw_params.valid_tx_ant;
1801         u8 tx_chains_num = priv->hw_params.tx_chains_num;
1802         int ret;
1803         u8 update_search_tbl_counter = 0;
1804
1805         if ((iwl_tx_ant_restriction(priv) == IWL_ANT_OK_SINGLE) &&
1806             (tbl->action < IWL_MIMO3_SWITCH_SISO_A ||
1807              tbl->action > IWL_MIMO3_SWITCH_SISO_C)) {
1808                 /* switch in SISO */
1809                 tbl->action = IWL_MIMO3_SWITCH_SISO_A;
1810         }
1811         for (;;) {
1812                 lq_sta->action_counter++;
1813                 switch (tbl->action) {
1814                 case IWL_MIMO3_SWITCH_ANTENNA1:
1815                 case IWL_MIMO3_SWITCH_ANTENNA2:
1816                         IWL_DEBUG_RATE(priv, "LQ: MIMO3 toggle Antennas\n");
1817
1818                         if (tx_chains_num <= 3)
1819                                 break;
1820
1821                         if (window->success_ratio >= IWL_RS_GOOD_RATIO)
1822                                 break;
1823
1824                         memcpy(search_tbl, tbl, sz);
1825                         if (rs_toggle_antenna(valid_tx_ant,
1826                                        &search_tbl->current_rate, search_tbl))
1827                                 goto out;
1828                         break;
1829                 case IWL_MIMO3_SWITCH_SISO_A:
1830                 case IWL_MIMO3_SWITCH_SISO_B:
1831                 case IWL_MIMO3_SWITCH_SISO_C:
1832                         IWL_DEBUG_RATE(priv, "LQ: MIMO3 switch to SISO\n");
1833
1834                         /* Set up new search table for SISO */
1835                         memcpy(search_tbl, tbl, sz);
1836
1837                         if (tbl->action == IWL_MIMO3_SWITCH_SISO_A)
1838                                 search_tbl->ant_type = ANT_A;
1839                         else if (tbl->action == IWL_MIMO3_SWITCH_SISO_B)
1840                                 search_tbl->ant_type = ANT_B;
1841                         else
1842                                 search_tbl->ant_type = ANT_C;
1843
1844                         if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
1845                                 break;
1846
1847                         ret = rs_switch_to_siso(priv, lq_sta, conf, sta,
1848                                                  search_tbl, index);
1849                         if (!ret)
1850                                 goto out;
1851
1852                         break;
1853
1854                 case IWL_MIMO3_SWITCH_MIMO2_AB:
1855                 case IWL_MIMO3_SWITCH_MIMO2_AC:
1856                 case IWL_MIMO3_SWITCH_MIMO2_BC:
1857                         IWL_DEBUG_RATE(priv, "LQ: MIMO3 switch to MIMO2\n");
1858
1859                         memcpy(search_tbl, tbl, sz);
1860                         search_tbl->is_SGI = 0;
1861                         if (tbl->action == IWL_MIMO3_SWITCH_MIMO2_AB)
1862                                 search_tbl->ant_type = ANT_AB;
1863                         else if (tbl->action == IWL_MIMO3_SWITCH_MIMO2_AC)
1864                                 search_tbl->ant_type = ANT_AC;
1865                         else
1866                                 search_tbl->ant_type = ANT_BC;
1867
1868                         if (!rs_is_valid_ant(valid_tx_ant, search_tbl->ant_type))
1869                                 break;
1870
1871                         ret = rs_switch_to_mimo2(priv, lq_sta, conf, sta,
1872                                                  search_tbl, index);
1873                         if (!ret)
1874                                 goto out;
1875
1876                         break;
1877
1878                 case IWL_MIMO3_SWITCH_GI:
1879                         if (!tbl->is_ht40 && !(ht_cap->cap &
1880                                                 IEEE80211_HT_CAP_SGI_20))
1881                                 break;
1882                         if (tbl->is_ht40 && !(ht_cap->cap &
1883                                                 IEEE80211_HT_CAP_SGI_40))
1884                                 break;
1885
1886                         IWL_DEBUG_RATE(priv, "LQ: MIMO3 toggle SGI/NGI\n");
1887
1888                         /* Set up new search table for MIMO */
1889                         memcpy(search_tbl, tbl, sz);
1890                         search_tbl->is_SGI = !tbl->is_SGI;
1891                         rs_set_expected_tpt_table(lq_sta, search_tbl);
1892                         /*
1893                          * If active table already uses the fastest possible
1894                          * modulation (dual stream with short guard interval),
1895                          * and it's working well, there's no need to look
1896                          * for a better type of modulation!
1897                          */
1898                         if (tbl->is_SGI) {
1899                                 s32 tpt = lq_sta->last_tpt / 100;
1900                                 if (tpt >= search_tbl->expected_tpt[index])
1901                                         break;
1902                         }
1903                         search_tbl->current_rate =
1904                                 rate_n_flags_from_tbl(priv, search_tbl,
1905                                                       index, is_green);
1906                         update_search_tbl_counter = 1;
1907                         goto out;
1908                 }
1909                 tbl->action++;
1910                 if (tbl->action > IWL_MIMO3_SWITCH_GI)
1911                         tbl->action = IWL_MIMO3_SWITCH_ANTENNA1;
1912
1913                 if (tbl->action == start_action)
1914                         break;
1915         }
1916         search_tbl->lq_type = LQ_NONE;
1917         return 0;
1918  out:
1919         lq_sta->search_better_tbl = 1;
1920         tbl->action++;
1921         if (tbl->action > IWL_MIMO3_SWITCH_GI)
1922                 tbl->action = IWL_MIMO3_SWITCH_ANTENNA1;
1923         if (update_search_tbl_counter)
1924                 search_tbl->action = tbl->action;
1925
1926         return 0;
1927
1928 }
1929
1930 /*
1931  * Check whether we should continue using same modulation mode, or
1932  * begin search for a new mode, based on:
1933  * 1) # tx successes or failures while using this mode
1934  * 2) # times calling this function
1935  * 3) elapsed time in this mode (not used, for now)
1936  */
1937 static void rs_stay_in_table(struct iwl_lq_sta *lq_sta)
1938 {
1939         struct iwl_scale_tbl_info *tbl;
1940         int i;
1941         int active_tbl;
1942         int flush_interval_passed = 0;
1943         struct iwl_priv *priv;
1944
1945         priv = lq_sta->drv;
1946         active_tbl = lq_sta->active_tbl;
1947
1948         tbl = &(lq_sta->lq_info[active_tbl]);
1949
1950         /* If we've been disallowing search, see if we should now allow it */
1951         if (lq_sta->stay_in_tbl) {
1952
1953                 /* Elapsed time using current modulation mode */
1954                 if (lq_sta->flush_timer)
1955                         flush_interval_passed =
1956                         time_after(jiffies,
1957                                         (unsigned long)(lq_sta->flush_timer +
1958                                         IWL_RATE_SCALE_FLUSH_INTVL));
1959
1960                 /*
1961                  * Check if we should allow search for new modulation mode.
1962                  * If many frames have failed or succeeded, or we've used
1963                  * this same modulation for a long time, allow search, and
1964                  * reset history stats that keep track of whether we should
1965                  * allow a new search.  Also (below) reset all bitmaps and
1966                  * stats in active history.
1967                  */
1968                 if ((lq_sta->total_failed > lq_sta->max_failure_limit) ||
1969                     (lq_sta->total_success > lq_sta->max_success_limit) ||
1970                     ((!lq_sta->search_better_tbl) && (lq_sta->flush_timer)
1971                      && (flush_interval_passed))) {
1972                         IWL_DEBUG_RATE(priv, "LQ: stay is expired %d %d %d\n:",
1973                                      lq_sta->total_failed,
1974                                      lq_sta->total_success,
1975                                      flush_interval_passed);
1976
1977                         /* Allow search for new mode */
1978                         lq_sta->stay_in_tbl = 0;        /* only place reset */
1979                         lq_sta->total_failed = 0;
1980                         lq_sta->total_success = 0;
1981                         lq_sta->flush_timer = 0;
1982
1983                 /*
1984                  * Else if we've used this modulation mode enough repetitions
1985                  * (regardless of elapsed time or success/failure), reset
1986                  * history bitmaps and rate-specific stats for all rates in
1987                  * active table.
1988                  */
1989                 } else {
1990                         lq_sta->table_count++;
1991                         if (lq_sta->table_count >=
1992                             lq_sta->table_count_limit) {
1993                                 lq_sta->table_count = 0;
1994
1995                                 IWL_DEBUG_RATE(priv, "LQ: stay in table clear win\n");
1996                                 for (i = 0; i < IWL_RATE_COUNT; i++)
1997                                         rs_rate_scale_clear_window(
1998                                                 &(tbl->win[i]));
1999                         }
2000                 }
2001
2002                 /* If transitioning to allow "search", reset all history
2003                  * bitmaps and stats in active table (this will become the new
2004                  * "search" table). */
2005                 if (!lq_sta->stay_in_tbl) {
2006                         for (i = 0; i < IWL_RATE_COUNT; i++)
2007                                 rs_rate_scale_clear_window(&(tbl->win[i]));
2008                 }
2009         }
2010 }
2011
2012 /*
2013  * setup rate table in uCode
2014  * return rate_n_flags as used in the table
2015  */
2016 static u32 rs_update_rate_tbl(struct iwl_priv *priv,
2017                                 struct iwl_lq_sta *lq_sta,
2018                                 struct iwl_scale_tbl_info *tbl,
2019                                 int index, u8 is_green)
2020 {
2021         u32 rate;
2022
2023         /* Update uCode's rate table. */
2024         rate = rate_n_flags_from_tbl(priv, tbl, index, is_green);
2025         rs_fill_link_cmd(priv, lq_sta, rate);
2026         iwl_send_lq_cmd(priv, &lq_sta->lq, CMD_ASYNC);
2027
2028         return rate;
2029 }
2030
2031 /*
2032  * Do rate scaling and search for new modulation mode.
2033  */
2034 static void rs_rate_scale_perform(struct iwl_priv *priv,
2035                                   struct sk_buff *skb,
2036                                   struct ieee80211_sta *sta,
2037                                   struct iwl_lq_sta *lq_sta)
2038 {
2039         struct ieee80211_hw *hw = priv->hw;
2040         struct ieee80211_conf *conf = &hw->conf;
2041         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2042         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
2043         int low = IWL_RATE_INVALID;
2044         int high = IWL_RATE_INVALID;
2045         int index;
2046         int i;
2047         struct iwl_rate_scale_data *window = NULL;
2048         int current_tpt = IWL_INVALID_VALUE;
2049         int low_tpt = IWL_INVALID_VALUE;
2050         int high_tpt = IWL_INVALID_VALUE;
2051         u32 fail_count;
2052         s8 scale_action = 0;
2053         u16 rate_mask;
2054         u8 update_lq = 0;
2055         struct iwl_scale_tbl_info *tbl, *tbl1;
2056         u16 rate_scale_index_msk = 0;
2057         u32 rate;
2058         u8 is_green = 0;
2059         u8 active_tbl = 0;
2060         u8 done_search = 0;
2061         u16 high_low;
2062         s32 sr;
2063         u8 tid = MAX_TID_COUNT;
2064         struct iwl_tid_data *tid_data;
2065
2066         IWL_DEBUG_RATE(priv, "rate scale calculate new rate for skb\n");
2067
2068         /* Send management frames and NO_ACK data using lowest rate. */
2069         /* TODO: this could probably be improved.. */
2070         if (!ieee80211_is_data(hdr->frame_control) ||
2071             info->flags & IEEE80211_TX_CTL_NO_ACK)
2072                 return;
2073
2074         if (!sta || !lq_sta)
2075                 return;
2076
2077         lq_sta->supp_rates = sta->supp_rates[lq_sta->band];
2078
2079         tid = rs_tl_add_packet(lq_sta, hdr);
2080
2081         /*
2082          * Select rate-scale / modulation-mode table to work with in
2083          * the rest of this function:  "search" if searching for better
2084          * modulation mode, or "active" if doing rate scaling within a mode.
2085          */
2086         if (!lq_sta->search_better_tbl)
2087                 active_tbl = lq_sta->active_tbl;
2088         else
2089                 active_tbl = 1 - lq_sta->active_tbl;
2090
2091         tbl = &(lq_sta->lq_info[active_tbl]);
2092         if (is_legacy(tbl->lq_type))
2093                 lq_sta->is_green = 0;
2094         else
2095                 lq_sta->is_green = rs_use_green(sta, &priv->current_ht_config);
2096         is_green = lq_sta->is_green;
2097
2098         /* current tx rate */
2099         index = lq_sta->last_txrate_idx;
2100
2101         IWL_DEBUG_RATE(priv, "Rate scale index %d for type %d\n", index,
2102                        tbl->lq_type);
2103
2104         /* rates available for this association, and for modulation mode */
2105         rate_mask = rs_get_supported_rates(lq_sta, hdr, tbl->lq_type);
2106
2107         IWL_DEBUG_RATE(priv, "mask 0x%04X \n", rate_mask);
2108
2109         /* mask with station rate restriction */
2110         if (is_legacy(tbl->lq_type)) {
2111                 if (lq_sta->band == IEEE80211_BAND_5GHZ)
2112                         /* supp_rates has no CCK bits in A mode */
2113                         rate_scale_index_msk = (u16) (rate_mask &
2114                                 (lq_sta->supp_rates << IWL_FIRST_OFDM_RATE));
2115                 else
2116                         rate_scale_index_msk = (u16) (rate_mask &
2117                                                       lq_sta->supp_rates);
2118
2119         } else
2120                 rate_scale_index_msk = rate_mask;
2121
2122         if (!rate_scale_index_msk)
2123                 rate_scale_index_msk = rate_mask;
2124
2125         if (!((1 << index) & rate_scale_index_msk)) {
2126                 IWL_ERR(priv, "Current Rate is not valid\n");
2127                 if (lq_sta->search_better_tbl) {
2128                         /* revert to active table if search table is not valid*/
2129                         tbl->lq_type = LQ_NONE;
2130                         lq_sta->search_better_tbl = 0;
2131                         tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
2132                         /* get "active" rate info */
2133                         index = iwl_hwrate_to_plcp_idx(tbl->current_rate);
2134                         rate = rs_update_rate_tbl(priv, lq_sta,
2135                                                   tbl, index, is_green);
2136                 }
2137                 return;
2138         }
2139
2140         /* Get expected throughput table and history window for current rate */
2141         if (!tbl->expected_tpt) {
2142                 IWL_ERR(priv, "tbl->expected_tpt is NULL\n");
2143                 return;
2144         }
2145
2146         /* force user max rate if set by user */
2147         if ((lq_sta->max_rate_idx != -1) &&
2148             (lq_sta->max_rate_idx < index)) {
2149                 index = lq_sta->max_rate_idx;
2150                 update_lq = 1;
2151                 window = &(tbl->win[index]);
2152                 goto lq_update;
2153         }
2154
2155         window = &(tbl->win[index]);
2156
2157         /*
2158          * If there is not enough history to calculate actual average
2159          * throughput, keep analyzing results of more tx frames, without
2160          * changing rate or mode (bypass most of the rest of this function).
2161          * Set up new rate table in uCode only if old rate is not supported
2162          * in current association (use new rate found above).
2163          */
2164         fail_count = window->counter - window->success_counter;
2165         if ((fail_count < IWL_RATE_MIN_FAILURE_TH) &&
2166                         (window->success_counter < IWL_RATE_MIN_SUCCESS_TH)) {
2167                 IWL_DEBUG_RATE(priv, "LQ: still below TH. succ=%d total=%d "
2168                                "for index %d\n",
2169                                window->success_counter, window->counter, index);
2170
2171                 /* Can't calculate this yet; not enough history */
2172                 window->average_tpt = IWL_INVALID_VALUE;
2173
2174                 /* Should we stay with this modulation mode,
2175                  * or search for a new one? */
2176                 rs_stay_in_table(lq_sta);
2177
2178                 goto out;
2179         }
2180
2181         /* Else we have enough samples; calculate estimate of
2182          * actual average throughput */
2183
2184         BUG_ON(window->average_tpt != ((window->success_ratio *
2185                         tbl->expected_tpt[index] + 64) / 128));
2186
2187         /* If we are searching for better modulation mode, check success. */
2188         if (lq_sta->search_better_tbl &&
2189             (iwl_tx_ant_restriction(priv) == IWL_ANT_OK_MULTI)) {
2190                 /* If good success, continue using the "search" mode;
2191                  * no need to send new link quality command, since we're
2192                  * continuing to use the setup that we've been trying. */
2193                 if (window->average_tpt > lq_sta->last_tpt) {
2194
2195                         IWL_DEBUG_RATE(priv, "LQ: SWITCHING TO NEW TABLE "
2196                                         "suc=%d cur-tpt=%d old-tpt=%d\n",
2197                                         window->success_ratio,
2198                                         window->average_tpt,
2199                                         lq_sta->last_tpt);
2200
2201                         if (!is_legacy(tbl->lq_type))
2202                                 lq_sta->enable_counter = 1;
2203
2204                         /* Swap tables; "search" becomes "active" */
2205                         lq_sta->active_tbl = active_tbl;
2206                         current_tpt = window->average_tpt;
2207
2208                 /* Else poor success; go back to mode in "active" table */
2209                 } else {
2210
2211                         IWL_DEBUG_RATE(priv, "LQ: GOING BACK TO THE OLD TABLE "
2212                                         "suc=%d cur-tpt=%d old-tpt=%d\n",
2213                                         window->success_ratio,
2214                                         window->average_tpt,
2215                                         lq_sta->last_tpt);
2216
2217                         /* Nullify "search" table */
2218                         tbl->lq_type = LQ_NONE;
2219
2220                         /* Revert to "active" table */
2221                         active_tbl = lq_sta->active_tbl;
2222                         tbl = &(lq_sta->lq_info[active_tbl]);
2223
2224                         /* Revert to "active" rate and throughput info */
2225                         index = iwl_hwrate_to_plcp_idx(tbl->current_rate);
2226                         current_tpt = lq_sta->last_tpt;
2227
2228                         /* Need to set up a new rate table in uCode */
2229                         update_lq = 1;
2230                 }
2231
2232                 /* Either way, we've made a decision; modulation mode
2233                  * search is done, allow rate adjustment next time. */
2234                 lq_sta->search_better_tbl = 0;
2235                 done_search = 1;        /* Don't switch modes below! */
2236                 goto lq_update;
2237         }
2238
2239         /* (Else) not in search of better modulation mode, try for better
2240          * starting rate, while staying in this mode. */
2241         high_low = rs_get_adjacent_rate(priv, index, rate_scale_index_msk,
2242                                         tbl->lq_type);
2243         low = high_low & 0xff;
2244         high = (high_low >> 8) & 0xff;
2245
2246         /* If user set max rate, dont allow higher than user constrain */
2247         if ((lq_sta->max_rate_idx != -1) &&
2248             (lq_sta->max_rate_idx < high))
2249                 high = IWL_RATE_INVALID;
2250
2251         sr = window->success_ratio;
2252
2253         /* Collect measured throughputs for current and adjacent rates */
2254         current_tpt = window->average_tpt;
2255         if (low != IWL_RATE_INVALID)
2256                 low_tpt = tbl->win[low].average_tpt;
2257         if (high != IWL_RATE_INVALID)
2258                 high_tpt = tbl->win[high].average_tpt;
2259
2260         scale_action = 0;
2261
2262         /* Too many failures, decrease rate */
2263         if ((sr <= IWL_RATE_DECREASE_TH) || (current_tpt == 0)) {
2264                 IWL_DEBUG_RATE(priv, "decrease rate because of low success_ratio\n");
2265                 scale_action = -1;
2266
2267         /* No throughput measured yet for adjacent rates; try increase. */
2268         } else if ((low_tpt == IWL_INVALID_VALUE) &&
2269                    (high_tpt == IWL_INVALID_VALUE)) {
2270
2271                 if (high != IWL_RATE_INVALID && sr >= IWL_RATE_INCREASE_TH)
2272                         scale_action = 1;
2273                 else if (low != IWL_RATE_INVALID)
2274                         scale_action = 0;
2275         }
2276
2277         /* Both adjacent throughputs are measured, but neither one has better
2278          * throughput; we're using the best rate, don't change it! */
2279         else if ((low_tpt != IWL_INVALID_VALUE) &&
2280                  (high_tpt != IWL_INVALID_VALUE) &&
2281                  (low_tpt < current_tpt) &&
2282                  (high_tpt < current_tpt))
2283                 scale_action = 0;
2284
2285         /* At least one adjacent rate's throughput is measured,
2286          * and may have better performance. */
2287         else {
2288                 /* Higher adjacent rate's throughput is measured */
2289                 if (high_tpt != IWL_INVALID_VALUE) {
2290                         /* Higher rate has better throughput */
2291                         if (high_tpt > current_tpt &&
2292                                         sr >= IWL_RATE_INCREASE_TH) {
2293                                 scale_action = 1;
2294                         } else {
2295                                 scale_action = 0;
2296                         }
2297
2298                 /* Lower adjacent rate's throughput is measured */
2299                 } else if (low_tpt != IWL_INVALID_VALUE) {
2300                         /* Lower rate has better throughput */
2301                         if (low_tpt > current_tpt) {
2302                                 IWL_DEBUG_RATE(priv,
2303                                     "decrease rate because of low tpt\n");
2304                                 scale_action = -1;
2305                         } else if (sr >= IWL_RATE_INCREASE_TH) {
2306                                 scale_action = 1;
2307                         }
2308                 }
2309         }
2310
2311         /* Sanity check; asked for decrease, but success rate or throughput
2312          * has been good at old rate.  Don't change it. */
2313         if ((scale_action == -1) && (low != IWL_RATE_INVALID) &&
2314                     ((sr > IWL_RATE_HIGH_TH) ||
2315                      (current_tpt > (100 * tbl->expected_tpt[low]))))
2316                 scale_action = 0;
2317         if (!iwl_ht_enabled(priv) && !is_legacy(tbl->lq_type))
2318                 scale_action = -1;
2319         if (iwl_tx_ant_restriction(priv) != IWL_ANT_OK_MULTI &&
2320                 (is_mimo2(tbl->lq_type) || is_mimo3(tbl->lq_type)))
2321                 scale_action = -1;
2322         switch (scale_action) {
2323         case -1:
2324                 /* Decrease starting rate, update uCode's rate table */
2325                 if (low != IWL_RATE_INVALID) {
2326                         update_lq = 1;
2327                         index = low;
2328                 }
2329
2330                 break;
2331         case 1:
2332                 /* Increase starting rate, update uCode's rate table */
2333                 if (high != IWL_RATE_INVALID) {
2334                         update_lq = 1;
2335                         index = high;
2336                 }
2337
2338                 break;
2339         case 0:
2340                 /* No change */
2341         default:
2342                 break;
2343         }
2344
2345         IWL_DEBUG_RATE(priv, "choose rate scale index %d action %d low %d "
2346                     "high %d type %d\n",
2347                      index, scale_action, low, high, tbl->lq_type);
2348
2349 lq_update:
2350         /* Replace uCode's rate table for the destination station. */
2351         if (update_lq)
2352                 rate = rs_update_rate_tbl(priv, lq_sta,
2353                                           tbl, index, is_green);
2354
2355         if (iwl_tx_ant_restriction(priv) == IWL_ANT_OK_MULTI) {
2356                 /* Should we stay with this modulation mode,
2357                  * or search for a new one? */
2358                 rs_stay_in_table(lq_sta);
2359         }
2360         /*
2361          * Search for new modulation mode if we're:
2362          * 1)  Not changing rates right now
2363          * 2)  Not just finishing up a search
2364          * 3)  Allowing a new search
2365          */
2366         if (!update_lq && !done_search && !lq_sta->stay_in_tbl && window->counter) {
2367                 /* Save current throughput to compare with "search" throughput*/
2368                 lq_sta->last_tpt = current_tpt;
2369
2370                 /* Select a new "search" modulation mode to try.
2371                  * If one is found, set up the new "search" table. */
2372                 if (is_legacy(tbl->lq_type))
2373                         rs_move_legacy_other(priv, lq_sta, conf, sta, index);
2374                 else if (is_siso(tbl->lq_type))
2375                         rs_move_siso_to_other(priv, lq_sta, conf, sta, index);
2376                 else if (is_mimo2(tbl->lq_type))
2377                         rs_move_mimo2_to_other(priv, lq_sta, conf, sta, index);
2378                 else
2379                         rs_move_mimo3_to_other(priv, lq_sta, conf, sta, index);
2380
2381                 /* If new "search" mode was selected, set up in uCode table */
2382                 if (lq_sta->search_better_tbl) {
2383                         /* Access the "search" table, clear its history. */
2384                         tbl = &(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
2385                         for (i = 0; i < IWL_RATE_COUNT; i++)
2386                                 rs_rate_scale_clear_window(&(tbl->win[i]));
2387
2388                         /* Use new "search" start rate */
2389                         index = iwl_hwrate_to_plcp_idx(tbl->current_rate);
2390
2391                         IWL_DEBUG_RATE(priv, "Switch current  mcs: %X index: %d\n",
2392                                      tbl->current_rate, index);
2393                         rs_fill_link_cmd(priv, lq_sta, tbl->current_rate);
2394                         iwl_send_lq_cmd(priv, &lq_sta->lq, CMD_ASYNC);
2395                 } else
2396                         done_search = 1;
2397         }
2398
2399         if (done_search && !lq_sta->stay_in_tbl) {
2400                 /* If the "active" (non-search) mode was legacy,
2401                  * and we've tried switching antennas,
2402                  * but we haven't been able to try HT modes (not available),
2403                  * stay with best antenna legacy modulation for a while
2404                  * before next round of mode comparisons. */
2405                 tbl1 = &(lq_sta->lq_info[lq_sta->active_tbl]);
2406                 if (is_legacy(tbl1->lq_type) && !conf_is_ht(conf) &&
2407                     lq_sta->action_counter > tbl1->max_search) {
2408                         IWL_DEBUG_RATE(priv, "LQ: STAY in legacy table\n");
2409                         rs_set_stay_in_table(priv, 1, lq_sta);
2410                 }
2411
2412                 /* If we're in an HT mode, and all 3 mode switch actions
2413                  * have been tried and compared, stay in this best modulation
2414                  * mode for a while before next round of mode comparisons. */
2415                 if (lq_sta->enable_counter &&
2416                     (lq_sta->action_counter >= tbl1->max_search) &&
2417                     iwl_ht_enabled(priv)) {
2418                         if ((lq_sta->last_tpt > IWL_AGG_TPT_THREHOLD) &&
2419                             (lq_sta->tx_agg_tid_en & (1 << tid)) &&
2420                             (tid != MAX_TID_COUNT)) {
2421                                 tid_data =
2422                                    &priv->stations[lq_sta->lq.sta_id].tid[tid];
2423                                 if (tid_data->agg.state == IWL_AGG_OFF) {
2424                                         IWL_DEBUG_RATE(priv,
2425                                                        "try to aggregate tid %d\n",
2426                                                        tid);
2427                                         rs_tl_turn_on_agg(priv, tid,
2428                                                           lq_sta, sta);
2429                                 }
2430                         }
2431                         rs_set_stay_in_table(priv, 0, lq_sta);
2432                 }
2433         }
2434
2435 out:
2436         tbl->current_rate = rate_n_flags_from_tbl(priv, tbl, index, is_green);
2437         i = index;
2438         lq_sta->last_txrate_idx = i;
2439
2440         return;
2441 }
2442
2443
2444 static void rs_initialize_lq(struct iwl_priv *priv,
2445                              struct ieee80211_conf *conf,
2446                              struct ieee80211_sta *sta,
2447                              struct iwl_lq_sta *lq_sta)
2448 {
2449         struct iwl_scale_tbl_info *tbl;
2450         int rate_idx;
2451         int i;
2452         u32 rate;
2453         u8 use_green = rs_use_green(sta, &priv->current_ht_config);
2454         u8 active_tbl = 0;
2455         u8 valid_tx_ant;
2456
2457         if (!sta || !lq_sta)
2458                 goto out;
2459
2460         i = lq_sta->last_txrate_idx;
2461
2462         if ((lq_sta->lq.sta_id == 0xff) &&
2463             (priv->iw_mode == NL80211_IFTYPE_ADHOC))
2464                 goto out;
2465
2466         valid_tx_ant = priv->hw_params.valid_tx_ant;
2467
2468         if (!lq_sta->search_better_tbl)
2469                 active_tbl = lq_sta->active_tbl;
2470         else
2471                 active_tbl = 1 - lq_sta->active_tbl;
2472
2473         tbl = &(lq_sta->lq_info[active_tbl]);
2474
2475         if ((i < 0) || (i >= IWL_RATE_COUNT))
2476                 i = 0;
2477
2478         rate = iwl_rates[i].plcp;
2479         tbl->ant_type = first_antenna(valid_tx_ant);
2480         rate |= tbl->ant_type << RATE_MCS_ANT_POS;
2481
2482         if (i >= IWL_FIRST_CCK_RATE && i <= IWL_LAST_CCK_RATE)
2483                 rate |= RATE_MCS_CCK_MSK;
2484
2485         rs_get_tbl_info_from_mcs(rate, priv->band, tbl, &rate_idx);
2486         if (!rs_is_valid_ant(valid_tx_ant, tbl->ant_type))
2487             rs_toggle_antenna(valid_tx_ant, &rate, tbl);
2488
2489         rate = rate_n_flags_from_tbl(priv, tbl, rate_idx, use_green);
2490         tbl->current_rate = rate;
2491         rs_set_expected_tpt_table(lq_sta, tbl);
2492         rs_fill_link_cmd(NULL, lq_sta, rate);
2493         iwl_send_lq_cmd(priv, &lq_sta->lq, CMD_ASYNC);
2494  out:
2495         return;
2496 }
2497
2498 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta, void *priv_sta,
2499                         struct ieee80211_tx_rate_control *txrc)
2500 {
2501
2502         struct sk_buff *skb = txrc->skb;
2503         struct ieee80211_supported_band *sband = txrc->sband;
2504         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
2505         struct ieee80211_conf *conf = &priv->hw->conf;
2506         struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
2507         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
2508         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
2509         struct iwl_lq_sta *lq_sta = priv_sta;
2510         int rate_idx;
2511
2512         IWL_DEBUG_RATE_LIMIT(priv, "rate scale calculate new rate for skb\n");
2513
2514         /* Get max rate if user set max rate */
2515         if (lq_sta) {
2516                 lq_sta->max_rate_idx = txrc->max_rate_idx;
2517                 if ((sband->band == IEEE80211_BAND_5GHZ) &&
2518                     (lq_sta->max_rate_idx != -1))
2519                         lq_sta->max_rate_idx += IWL_FIRST_OFDM_RATE;
2520                 if ((lq_sta->max_rate_idx < 0) ||
2521                     (lq_sta->max_rate_idx >= IWL_RATE_COUNT))
2522                         lq_sta->max_rate_idx = -1;
2523         }
2524
2525         /* Send management frames and NO_ACK data using lowest rate. */
2526         if (rate_control_send_low(sta, priv_sta, txrc))
2527                 return;
2528
2529         rate_idx  = lq_sta->last_txrate_idx;
2530
2531         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
2532             !lq_sta->ibss_sta_added) {
2533                 u8 sta_id = iwl_find_station(priv, hdr->addr1);
2534
2535                 if (sta_id == IWL_INVALID_STATION) {
2536                         IWL_DEBUG_RATE(priv, "LQ: ADD station %pM\n",
2537                                        hdr->addr1);
2538                         sta_id = iwl_add_station(priv, hdr->addr1,
2539                                                 false, CMD_ASYNC, ht_cap);
2540                 }
2541                 if ((sta_id != IWL_INVALID_STATION)) {
2542                         lq_sta->lq.sta_id = sta_id;
2543                         lq_sta->lq.rs_table[0].rate_n_flags = 0;
2544                         lq_sta->ibss_sta_added = 1;
2545                         rs_initialize_lq(priv, conf, sta, lq_sta);
2546                 }
2547         }
2548
2549         if (lq_sta->last_rate_n_flags & RATE_MCS_HT_MSK) {
2550                 rate_idx -= IWL_FIRST_OFDM_RATE;
2551                 /* 6M and 9M shared same MCS index */
2552                 rate_idx = (rate_idx > 0) ? (rate_idx - 1) : 0;
2553                 if (rs_extract_rate(lq_sta->last_rate_n_flags) >=
2554                     IWL_RATE_MIMO3_6M_PLCP)
2555                         rate_idx = rate_idx + (2 * MCS_INDEX_PER_STREAM);
2556                 else if (rs_extract_rate(lq_sta->last_rate_n_flags) >=
2557                          IWL_RATE_MIMO2_6M_PLCP)
2558                         rate_idx = rate_idx + MCS_INDEX_PER_STREAM;
2559                 info->control.rates[0].flags = IEEE80211_TX_RC_MCS;
2560                 if (lq_sta->last_rate_n_flags & RATE_MCS_SGI_MSK)
2561                         info->control.rates[0].flags |= IEEE80211_TX_RC_SHORT_GI;
2562                 if (lq_sta->last_rate_n_flags & RATE_MCS_DUP_MSK)
2563                         info->control.rates[0].flags |= IEEE80211_TX_RC_DUP_DATA;
2564                 if (lq_sta->last_rate_n_flags & RATE_MCS_HT40_MSK)
2565                         info->control.rates[0].flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
2566                 if (lq_sta->last_rate_n_flags & RATE_MCS_GF_MSK)
2567                         info->control.rates[0].flags |= IEEE80211_TX_RC_GREEN_FIELD;
2568         } else {
2569                 /* Check for invalid rates */
2570                 if ((rate_idx < 0) || (rate_idx >= IWL_RATE_COUNT_LEGACY) ||
2571                                 ((sband->band == IEEE80211_BAND_5GHZ) &&
2572                                  (rate_idx < IWL_FIRST_OFDM_RATE)))
2573                         rate_idx = rate_lowest_index(sband, sta);
2574                 /* On valid 5 GHz rate, adjust index */
2575                 else if (sband->band == IEEE80211_BAND_5GHZ)
2576                         rate_idx -= IWL_FIRST_OFDM_RATE;
2577                 info->control.rates[0].flags = 0;
2578         }
2579         info->control.rates[0].idx = rate_idx;
2580
2581 }
2582
2583 static void *rs_alloc_sta(void *priv_rate, struct ieee80211_sta *sta,
2584                           gfp_t gfp)
2585 {
2586         struct iwl_lq_sta *lq_sta;
2587         struct iwl_priv *priv;
2588         int i, j;
2589
2590         priv = (struct iwl_priv *)priv_rate;
2591         IWL_DEBUG_RATE(priv, "create station rate scale window\n");
2592
2593         lq_sta = kzalloc(sizeof(struct iwl_lq_sta), gfp);
2594
2595         if (lq_sta == NULL)
2596                 return NULL;
2597         lq_sta->lq.sta_id = 0xff;
2598
2599
2600         for (j = 0; j < LQ_SIZE; j++)
2601                 for (i = 0; i < IWL_RATE_COUNT; i++)
2602                         rs_rate_scale_clear_window(&lq_sta->lq_info[j].win[i]);
2603
2604         return lq_sta;
2605 }
2606
2607 static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
2608                          struct ieee80211_sta *sta, void *priv_sta)
2609 {
2610         int i, j;
2611         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
2612         struct ieee80211_conf *conf = &priv->hw->conf;
2613         struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
2614         struct iwl_lq_sta *lq_sta = priv_sta;
2615
2616         lq_sta->flush_timer = 0;
2617         lq_sta->supp_rates = sta->supp_rates[sband->band];
2618         for (j = 0; j < LQ_SIZE; j++)
2619                 for (i = 0; i < IWL_RATE_COUNT; i++)
2620                         rs_rate_scale_clear_window(&lq_sta->lq_info[j].win[i]);
2621
2622         IWL_DEBUG_RATE(priv, "LQ: *** rate scale station global init ***\n");
2623         /* TODO: what is a good starting rate for STA? About middle? Maybe not
2624          * the lowest or the highest rate.. Could consider using RSSI from
2625          * previous packets? Need to have IEEE 802.1X auth succeed immediately
2626          * after assoc.. */
2627
2628         lq_sta->ibss_sta_added = 0;
2629         if (priv->iw_mode == NL80211_IFTYPE_AP) {
2630                 u8 sta_id = iwl_find_station(priv,
2631                                                                 sta->addr);
2632
2633                 /* for IBSS the call are from tasklet */
2634                 IWL_DEBUG_RATE(priv, "LQ: ADD station %pM\n", sta->addr);
2635
2636                 if (sta_id == IWL_INVALID_STATION) {
2637                         IWL_DEBUG_RATE(priv, "LQ: ADD station %pM\n", sta->addr);
2638                         sta_id = iwl_add_station(priv, sta->addr, false,
2639                                                 CMD_ASYNC, ht_cap);
2640                 }
2641                 if ((sta_id != IWL_INVALID_STATION)) {
2642                         lq_sta->lq.sta_id = sta_id;
2643                         lq_sta->lq.rs_table[0].rate_n_flags = 0;
2644                 }
2645                 /* FIXME: this is w/a remove it later */
2646                 priv->assoc_station_added = 1;
2647         }
2648
2649         lq_sta->is_dup = 0;
2650         lq_sta->max_rate_idx = -1;
2651         lq_sta->missed_rate_counter = IWL_MISSED_RATE_MAX;
2652         lq_sta->is_green = rs_use_green(sta, &priv->current_ht_config);
2653         lq_sta->active_legacy_rate = priv->active_rate & ~(0x1000);
2654         lq_sta->active_rate_basic = priv->active_rate_basic;
2655         lq_sta->band = priv->band;
2656         /*
2657          * active_siso_rate mask includes 9 MBits (bit 5), and CCK (bits 0-3),
2658          * supp_rates[] does not; shift to convert format, force 9 MBits off.
2659          */
2660         lq_sta->active_siso_rate = ht_cap->mcs.rx_mask[0] << 1;
2661         lq_sta->active_siso_rate |= ht_cap->mcs.rx_mask[0] & 0x1;
2662         lq_sta->active_siso_rate &= ~((u16)0x2);
2663         lq_sta->active_siso_rate <<= IWL_FIRST_OFDM_RATE;
2664
2665         /* Same here */
2666         lq_sta->active_mimo2_rate = ht_cap->mcs.rx_mask[1] << 1;
2667         lq_sta->active_mimo2_rate |= ht_cap->mcs.rx_mask[1] & 0x1;
2668         lq_sta->active_mimo2_rate &= ~((u16)0x2);
2669         lq_sta->active_mimo2_rate <<= IWL_FIRST_OFDM_RATE;
2670
2671         lq_sta->active_mimo3_rate = ht_cap->mcs.rx_mask[2] << 1;
2672         lq_sta->active_mimo3_rate |= ht_cap->mcs.rx_mask[2] & 0x1;
2673         lq_sta->active_mimo3_rate &= ~((u16)0x2);
2674         lq_sta->active_mimo3_rate <<= IWL_FIRST_OFDM_RATE;
2675
2676         IWL_DEBUG_RATE(priv, "SISO-RATE=%X MIMO2-RATE=%X MIMO3-RATE=%X\n",
2677                      lq_sta->active_siso_rate,
2678                      lq_sta->active_mimo2_rate,
2679                      lq_sta->active_mimo3_rate);
2680
2681         /* These values will be overridden later */
2682         lq_sta->lq.general_params.single_stream_ant_msk = ANT_A;
2683         lq_sta->lq.general_params.dual_stream_ant_msk = ANT_AB;
2684
2685         /* as default allow aggregation for all tids */
2686         lq_sta->tx_agg_tid_en = IWL_AGG_ALL_TID;
2687         lq_sta->drv = priv;
2688
2689         /* Set last_txrate_idx to lowest rate */
2690         lq_sta->last_txrate_idx = rate_lowest_index(sband, sta);
2691         if (sband->band == IEEE80211_BAND_5GHZ)
2692                 lq_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
2693
2694         rs_initialize_lq(priv, conf, sta, lq_sta);
2695 }
2696
2697 static void rs_fill_link_cmd(struct iwl_priv *priv,
2698                              struct iwl_lq_sta *lq_sta, u32 new_rate)
2699 {
2700         struct iwl_scale_tbl_info tbl_type;
2701         int index = 0;
2702         int rate_idx;
2703         int repeat_rate = 0;
2704         u8 ant_toggle_cnt = 0;
2705         u8 use_ht_possible = 1;
2706         u8 valid_tx_ant = 0;
2707         struct iwl_link_quality_cmd *lq_cmd = &lq_sta->lq;
2708
2709         /* Override starting rate (index 0) if needed for debug purposes */
2710         rs_dbgfs_set_mcs(lq_sta, &new_rate, index);
2711
2712         /* Interpret new_rate (rate_n_flags) */
2713         memset(&tbl_type, 0, sizeof(tbl_type));
2714         rs_get_tbl_info_from_mcs(new_rate, lq_sta->band,
2715                                   &tbl_type, &rate_idx);
2716
2717         /* How many times should we repeat the initial rate? */
2718         if (is_legacy(tbl_type.lq_type)) {
2719                 ant_toggle_cnt = 1;
2720                 repeat_rate = IWL_NUMBER_TRY;
2721         } else {
2722                 repeat_rate = IWL_HT_NUMBER_TRY;
2723         }
2724
2725         lq_cmd->general_params.mimo_delimiter =
2726                         is_mimo(tbl_type.lq_type) ? 1 : 0;
2727
2728         /* Fill 1st table entry (index 0) */
2729         lq_cmd->rs_table[index].rate_n_flags = cpu_to_le32(new_rate);
2730
2731         if (num_of_ant(tbl_type.ant_type) == 1) {
2732                 lq_cmd->general_params.single_stream_ant_msk =
2733                                                 tbl_type.ant_type;
2734         } else if (num_of_ant(tbl_type.ant_type) == 2) {
2735                 lq_cmd->general_params.dual_stream_ant_msk =
2736                                                 tbl_type.ant_type;
2737         } /* otherwise we don't modify the existing value */
2738
2739         index++;
2740         repeat_rate--;
2741
2742         if (priv)
2743                 valid_tx_ant = priv->hw_params.valid_tx_ant;
2744
2745         /* Fill rest of rate table */
2746         while (index < LINK_QUAL_MAX_RETRY_NUM) {
2747                 /* Repeat initial/next rate.
2748                  * For legacy IWL_NUMBER_TRY == 1, this loop will not execute.
2749                  * For HT IWL_HT_NUMBER_TRY == 3, this executes twice. */
2750                 while (repeat_rate > 0 && (index < LINK_QUAL_MAX_RETRY_NUM)) {
2751                         if (is_legacy(tbl_type.lq_type)) {
2752                                 if (ant_toggle_cnt < NUM_TRY_BEFORE_ANT_TOGGLE)
2753                                         ant_toggle_cnt++;
2754                                 else if (priv &&
2755                                          rs_toggle_antenna(valid_tx_ant,
2756                                                         &new_rate, &tbl_type))
2757                                         ant_toggle_cnt = 1;
2758 }
2759
2760                         /* Override next rate if needed for debug purposes */
2761                         rs_dbgfs_set_mcs(lq_sta, &new_rate, index);
2762
2763                         /* Fill next table entry */
2764                         lq_cmd->rs_table[index].rate_n_flags =
2765                                         cpu_to_le32(new_rate);
2766                         repeat_rate--;
2767                         index++;
2768                 }
2769
2770                 rs_get_tbl_info_from_mcs(new_rate, lq_sta->band, &tbl_type,
2771                                                 &rate_idx);
2772
2773                 /* Indicate to uCode which entries might be MIMO.
2774                  * If initial rate was MIMO, this will finally end up
2775                  * as (IWL_HT_NUMBER_TRY * 2), after 2nd pass, otherwise 0. */
2776                 if (is_mimo(tbl_type.lq_type))
2777                         lq_cmd->general_params.mimo_delimiter = index;
2778
2779                 /* Get next rate */
2780                 new_rate = rs_get_lower_rate(lq_sta, &tbl_type, rate_idx,
2781                                              use_ht_possible);
2782
2783                 /* How many times should we repeat the next rate? */
2784                 if (is_legacy(tbl_type.lq_type)) {
2785                         if (ant_toggle_cnt < NUM_TRY_BEFORE_ANT_TOGGLE)
2786                                 ant_toggle_cnt++;
2787                         else if (priv &&
2788                                  rs_toggle_antenna(valid_tx_ant,
2789                                                    &new_rate, &tbl_type))
2790                                 ant_toggle_cnt = 1;
2791
2792                         repeat_rate = IWL_NUMBER_TRY;
2793                 } else {
2794                         repeat_rate = IWL_HT_NUMBER_TRY;
2795                 }
2796
2797                 /* Don't allow HT rates after next pass.
2798                  * rs_get_lower_rate() will change type to LQ_A or LQ_G. */
2799                 use_ht_possible = 0;
2800
2801                 /* Override next rate if needed for debug purposes */
2802                 rs_dbgfs_set_mcs(lq_sta, &new_rate, index);
2803
2804                 /* Fill next table entry */
2805                 lq_cmd->rs_table[index].rate_n_flags = cpu_to_le32(new_rate);
2806
2807                 index++;
2808                 repeat_rate--;
2809         }
2810
2811         lq_cmd->agg_params.agg_frame_cnt_limit = LINK_QUAL_AGG_FRAME_LIMIT_MAX;
2812         lq_cmd->agg_params.agg_dis_start_th = LINK_QUAL_AGG_DISABLE_START_DEF;
2813         lq_cmd->agg_params.agg_time_limit =
2814                 cpu_to_le16(LINK_QUAL_AGG_TIME_LIMIT_DEF);
2815 }
2816
2817 static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
2818 {
2819         return hw->priv;
2820 }
2821 /* rate scale requires free function to be implemented */
2822 static void rs_free(void *priv_rate)
2823 {
2824         return;
2825 }
2826
2827 static void rs_free_sta(void *priv_r, struct ieee80211_sta *sta,
2828                         void *priv_sta)
2829 {
2830         struct iwl_lq_sta *lq_sta = priv_sta;
2831         struct iwl_priv *priv __maybe_unused = priv_r;
2832
2833         IWL_DEBUG_RATE(priv, "enter\n");
2834         kfree(lq_sta);
2835         IWL_DEBUG_RATE(priv, "leave\n");
2836 }
2837
2838
2839 #ifdef CONFIG_MAC80211_DEBUGFS
2840 static int open_file_generic(struct inode *inode, struct file *file)
2841 {
2842         file->private_data = inode->i_private;
2843         return 0;
2844 }
2845 static void rs_dbgfs_set_mcs(struct iwl_lq_sta *lq_sta,
2846                              u32 *rate_n_flags, int index)
2847 {
2848         struct iwl_priv *priv;
2849         u8 valid_tx_ant;
2850         u8 ant_sel_tx;
2851
2852         priv = lq_sta->drv;
2853         valid_tx_ant = priv->hw_params.valid_tx_ant;
2854         if (lq_sta->dbg_fixed_rate) {
2855                 ant_sel_tx =
2856                   ((lq_sta->dbg_fixed_rate & RATE_MCS_ANT_ABC_MSK)
2857                   >> RATE_MCS_ANT_POS);
2858                 if ((valid_tx_ant & ant_sel_tx) == ant_sel_tx) {
2859                         *rate_n_flags = lq_sta->dbg_fixed_rate;
2860                         IWL_DEBUG_RATE(priv, "Fixed rate ON\n");
2861                 } else {
2862                         lq_sta->dbg_fixed_rate = 0;
2863                         IWL_ERR(priv,
2864                             "Invalid antenna selection 0x%X, Valid is 0x%X\n",
2865                             ant_sel_tx, valid_tx_ant);
2866                         IWL_DEBUG_RATE(priv, "Fixed rate OFF\n");
2867                 }
2868         } else {
2869                 IWL_DEBUG_RATE(priv, "Fixed rate OFF\n");
2870         }
2871 }
2872
2873 static ssize_t rs_sta_dbgfs_scale_table_write(struct file *file,
2874                         const char __user *user_buf, size_t count, loff_t *ppos)
2875 {
2876         struct iwl_lq_sta *lq_sta = file->private_data;
2877         struct iwl_priv *priv;
2878         char buf[64];
2879         int buf_size;
2880         u32 parsed_rate;
2881
2882         priv = lq_sta->drv;
2883         memset(buf, 0, sizeof(buf));
2884         buf_size = min(count, sizeof(buf) -  1);
2885         if (copy_from_user(buf, user_buf, buf_size))
2886                 return -EFAULT;
2887
2888         if (sscanf(buf, "%x", &parsed_rate) == 1)
2889                 lq_sta->dbg_fixed_rate = parsed_rate;
2890         else
2891                 lq_sta->dbg_fixed_rate = 0;
2892
2893         lq_sta->active_legacy_rate = 0x0FFF;    /* 1 - 54 MBits, includes CCK */
2894         lq_sta->active_siso_rate   = 0x1FD0;    /* 6 - 60 MBits, no 9, no CCK */
2895         lq_sta->active_mimo2_rate  = 0x1FD0;    /* 6 - 60 MBits, no 9, no CCK */
2896         lq_sta->active_mimo3_rate  = 0x1FD0;    /* 6 - 60 MBits, no 9, no CCK */
2897
2898         IWL_DEBUG_RATE(priv, "sta_id %d rate 0x%X\n",
2899                 lq_sta->lq.sta_id, lq_sta->dbg_fixed_rate);
2900
2901         if (lq_sta->dbg_fixed_rate) {
2902                 rs_fill_link_cmd(NULL, lq_sta, lq_sta->dbg_fixed_rate);
2903                 iwl_send_lq_cmd(lq_sta->drv, &lq_sta->lq, CMD_ASYNC);
2904         }
2905
2906         return count;
2907 }
2908
2909 static ssize_t rs_sta_dbgfs_scale_table_read(struct file *file,
2910                         char __user *user_buf, size_t count, loff_t *ppos)
2911 {
2912         char *buff;
2913         int desc = 0;
2914         int i = 0;
2915         int index = 0;
2916         ssize_t ret;
2917
2918         struct iwl_lq_sta *lq_sta = file->private_data;
2919         struct iwl_priv *priv;
2920         struct iwl_scale_tbl_info *tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
2921
2922         priv = lq_sta->drv;
2923         buff = kmalloc(1024, GFP_KERNEL);
2924         if (!buff)
2925                 return -ENOMEM;
2926
2927         desc += sprintf(buff+desc, "sta_id %d\n", lq_sta->lq.sta_id);
2928         desc += sprintf(buff+desc, "failed=%d success=%d rate=0%X\n",
2929                         lq_sta->total_failed, lq_sta->total_success,
2930                         lq_sta->active_legacy_rate);
2931         desc += sprintf(buff+desc, "fixed rate 0x%X\n",
2932                         lq_sta->dbg_fixed_rate);
2933         desc += sprintf(buff+desc, "valid_tx_ant %s%s%s\n",