rt2870_amrr.c

   1
   2 /*-
   3  * Copyright (c) 2009-2010 Alexander Egorenkov <egorenar@gmail.com>
   4  * Copyright (c) 2009 Damien Bergamini <damien.bergamini@free.fr>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/param.h>
  20 #include <sys/kernel.h>
  21 #include <sys/module.h>
  22 #include <sys/socket.h>
  23 #include <sys/sysctl.h>
  24
  25 #include <net/if.h>
  26 #include <net/if_media.h>
  27
  28 #include <net80211/ieee80211_var.h>
  29
  30 #include "rt2870_amrr.h"
  31
  32 /*
  33  * Defines and macros
  34  */
  35
  36 #define RT2870_AMRR_IS_SUCCESS(amrr_node)                               ((amrr_node)->retrycnt < (amrr_node)->txcnt / 10)
  37
  38 #define RT2870_AMRR_IS_FAILURE(amrr_node)                               ((amrr_node)->retrycnt > (amrr_node)->txcnt / 3)
  39
  40 #define RT2870_AMRR_IS_ENOUGH(amrr_node)                                ((amrr_node)->txcnt > 10)
  41
  42 /*
  43  * Static function prototypes
  44  */
  45
  46 static int rt2870_amrr_update(struct rt2870_amrr *amrr,
  47         struct rt2870_amrr_node *amrr_node, struct ieee80211_node *ni);
  48
  49 /*
  50  * rt2870_amrr_init
  51  */
  52 void rt2870_amrr_init(struct rt2870_amrr *amrr, struct ieee80211com *ic,
  53         int ntxpath, int min_success_threshold, int max_success_threshold, int msecs)
  54 {
  55         int t;
  56
  57         amrr->ntxpath = ntxpath;
  58
  59         amrr->min_success_threshold = min_success_threshold;
  60         amrr->max_success_threshold = max_success_threshold;
  61
  62         if (msecs < 100)
  63                 msecs = 100;
  64
  65         t = msecs_to_ticks(msecs);
  66
  67         amrr->interval = (t < 1) ? 1 : t;
  68 }
  69
  70 /*
  71  * rt2870_amrr_cleanup
  72  */
  73 void rt2870_amrr_cleanup(struct rt2870_amrr *amrr)
  74 {
  75 }
  76
  77 /*
  78  * rt2870_amrr_node_init
  79  */
  80 void rt2870_amrr_node_init(struct rt2870_amrr *amrr,
  81     struct rt2870_amrr_node *amrr_node, struct ieee80211_node *ni)
  82 {
  83         const struct ieee80211_rateset *rs;
  84
  85         rs = &ni->ni_rates;
  86
  87         amrr_node->amrr = amrr;
  88         amrr_node->success = 0;
  89         amrr_node->recovery = 0;
  90         amrr_node->txcnt = 0;
  91         amrr_node->retrycnt = 0;
  92         amrr_node->success_threshold = amrr->min_success_threshold;
  93
  94         if (ni->ni_flags & IEEE80211_NODE_HT)
  95         {
  96                 rs = (const struct ieee80211_rateset *) &ni->ni_htrates;
  97
  98                 for (ni->ni_txrate = rs->rs_nrates - 1;
  99                         ni->ni_txrate > 0 && (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) > 4;
 100                         ni->ni_txrate--) ;
 101         }
 102         else
 103         {
 104                 rs = &ni->ni_rates;
 105
 106                 for (ni->ni_txrate = rs->rs_nrates - 1;
 107                         ni->ni_txrate > 0 && (rs->rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL) > 72;
 108                         ni->ni_txrate--) ;
 109         }
 110
 111         amrr_node->ticks = ticks;
 112 }
 113
 114 /*
 115  * rt2870_amrr_choose
 116  */
 117 int rt2870_amrr_choose(struct ieee80211_node *ni,
 118         struct rt2870_amrr_node *amrr_node)
 119 {
 120         struct rt2870_amrr *amrr;
 121         int rate_index;
 122
 123         amrr = amrr_node->amrr;
 124
 125         if (RT2870_AMRR_IS_ENOUGH(amrr_node) &&
 126                 (ticks - amrr_node->ticks) > amrr->interval)
 127         {
 128                 rate_index = rt2870_amrr_update(amrr, amrr_node, ni);
 129                 if (rate_index != ni->ni_txrate)
 130                         ni->ni_txrate = rate_index;
 131
 132                 amrr_node->ticks = ticks;
 133         }
 134         else
 135         {
 136                 rate_index = ni->ni_txrate;
 137         }
 138
 139         return rate_index;
 140 }
 141
 142 /*
 143  * rt2870_amrr_update
 144  */
 145 static int rt2870_amrr_update(struct rt2870_amrr *amrr,
 146         struct rt2870_amrr_node *amrr_node, struct ieee80211_node *ni)
 147 {
 148         const struct ieee80211_rateset *rs;
 149         int rate_index;
 150
 151         KASSERT(RT2870_AMRR_IS_ENOUGH(amrr_node),
 152                 ("not enough Tx count: txcnt=%d",
 153                  amrr_node->txcnt));
 154
 155         if (ni->ni_flags & IEEE80211_NODE_HT)
 156                 rs = (const struct ieee80211_rateset *) &ni->ni_htrates;
 157         else
 158                 rs = &ni->ni_rates;
 159
 160         rate_index = ni->ni_txrate;
 161
 162         if (RT2870_AMRR_IS_SUCCESS(amrr_node))
 163         {
 164                 amrr_node->success++;
 165                 if ((amrr_node->success >= amrr_node->success_threshold) &&
 166                     (rate_index + 1 < rs->rs_nrates) &&
 167                         (!(ni->ni_flags & IEEE80211_NODE_HT) || (rs->rs_rates[rate_index + 1] & IEEE80211_RATE_VAL) < (amrr->ntxpath * 8)))
 168                 {
 169                         amrr_node->recovery = 1;
 170                         amrr_node->success = 0;
 171
 172                         rate_index++;
 173                 }
 174                 else
 175                 {
 176                         amrr_node->recovery = 0;
 177                 }
 178         }
 179         else if (RT2870_AMRR_IS_FAILURE(amrr_node))
 180         {
 181                 amrr_node->success = 0;
 182
 183                 if (rate_index > 0)
 184                 {
 185                         if (amrr_node->recovery)
 186                         {
 187                                 amrr_node->success_threshold *= 2;
 188                                 if (amrr_node->success_threshold > amrr->max_success_threshold)
 189                                         amrr_node->success_threshold = amrr->max_success_threshold;
 190                         }
 191                         else
 192                         {
 193                                 amrr_node->success_threshold = amrr->min_success_threshold;
 194                         }
 195
 196                         rate_index--;
 197                 }
 198
 199                 amrr_node->recovery = 0;
 200         }
 201
 202         amrr_node->txcnt = 0;
 203         amrr_node->retrycnt = 0;
 204
 205         return rate_index;
 206 }