2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005, Devicescape Software, Inc.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/netdevice.h>
13 #include <linux/types.h>
14 #include <linux/slab.h>
15 #include <linux/skbuff.h>
16 #include <linux/compiler.h>
18 #include <net/mac80211.h>
19 #include "ieee80211_i.h"
20 #include "ieee80211_rate.h"
23 /* This is a minimal implementation of TX rate controlling that can be used
24 * as the default when no improved mechanisms are available. */
27 #define RATE_CONTROL_EMERG_DEC 2
28 #define RATE_CONTROL_INTERVAL (HZ / 20)
29 #define RATE_CONTROL_MIN_TX 10
31 MODULE_ALIAS("rc80211_default");
33 static void rate_control_rate_inc(struct ieee80211_local *local,
36 struct ieee80211_sub_if_data *sdata;
37 struct ieee80211_hw_mode *mode;
41 sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
42 if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
43 /* forced unicast rate - do not change STA rate */
47 mode = local->oper_hw_mode;
48 maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
50 if (i > mode->num_rates)
51 i = mode->num_rates - 2;
53 while (i + 1 < mode->num_rates) {
55 if (sta->supp_rates & BIT(i) &&
56 mode->rates[i].flags & IEEE80211_RATE_SUPPORTED &&
57 (maxrate < 0 || i <= maxrate)) {
65 static void rate_control_rate_dec(struct ieee80211_local *local,
68 struct ieee80211_sub_if_data *sdata;
69 struct ieee80211_hw_mode *mode;
72 sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
73 if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
74 /* forced unicast rate - do not change STA rate */
78 mode = local->oper_hw_mode;
79 if (i > mode->num_rates)
84 if (sta->supp_rates & BIT(i) &&
85 mode->rates[i].flags & IEEE80211_RATE_SUPPORTED) {
93 static struct ieee80211_rate *
94 rate_control_lowest_rate(struct ieee80211_local *local,
95 struct ieee80211_hw_mode *mode)
99 for (i = 0; i < mode->num_rates; i++) {
100 struct ieee80211_rate *rate = &mode->rates[i];
102 if (rate->flags & IEEE80211_RATE_SUPPORTED)
106 printk(KERN_DEBUG "rate_control_lowest_rate - no supported rates "
108 return &mode->rates[0];
112 struct global_rate_control {
116 struct sta_rate_control {
117 unsigned long last_rate_change;
121 unsigned long avg_rate_update;
127 static void rate_control_simple_tx_status(void *priv, struct net_device *dev,
129 struct ieee80211_tx_status *status)
131 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
132 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
133 struct sta_info *sta;
134 struct sta_rate_control *srctrl;
136 sta = sta_info_get(local, hdr->addr1);
141 srctrl = sta->rate_ctrl_priv;
142 srctrl->tx_num_xmit++;
143 if (status->excessive_retries) {
144 sta->antenna_sel_tx = sta->antenna_sel_tx == 1 ? 2 : 1;
145 sta->antenna_sel_rx = sta->antenna_sel_rx == 1 ? 2 : 1;
146 if (local->sta_antenna_sel == STA_ANTENNA_SEL_SW_CTRL_DEBUG) {
147 printk(KERN_DEBUG "%s: " MAC_FMT " TX antenna --> %d "
148 "RX antenna --> %d (@%lu)\n",
149 dev->name, MAC_ARG(hdr->addr1),
150 sta->antenna_sel_tx, sta->antenna_sel_rx, jiffies);
152 srctrl->tx_num_failures++;
153 sta->tx_retry_failed++;
154 sta->tx_num_consecutive_failures++;
155 sta->tx_num_mpdu_fail++;
157 sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
158 sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
159 sta->last_ack_rssi[2] = status->ack_signal;
160 sta->tx_num_consecutive_failures = 0;
161 sta->tx_num_mpdu_ok++;
163 sta->tx_retry_count += status->retry_count;
164 sta->tx_num_mpdu_fail += status->retry_count;
166 if (time_after(jiffies,
167 srctrl->last_rate_change + RATE_CONTROL_INTERVAL) &&
168 srctrl->tx_num_xmit > RATE_CONTROL_MIN_TX) {
170 srctrl->last_rate_change = jiffies;
172 per_failed = (100 * sta->tx_num_mpdu_fail) /
173 (sta->tx_num_mpdu_fail + sta->tx_num_mpdu_ok);
174 /* TODO: calculate average per_failed to make adjusting
175 * parameters easier */
177 if (net_ratelimit()) {
178 printk(KERN_DEBUG "MPDU fail=%d ok=%d per_failed=%d\n",
179 sta->tx_num_mpdu_fail, sta->tx_num_mpdu_ok,
184 if (per_failed > local->rate_ctrl_num_down) {
185 rate_control_rate_dec(local, sta);
186 } else if (per_failed < local->rate_ctrl_num_up) {
187 rate_control_rate_inc(local, sta);
189 srctrl->tx_avg_rate_sum += status->control.rate->rate;
190 srctrl->tx_avg_rate_num++;
191 srctrl->tx_num_failures = 0;
192 srctrl->tx_num_xmit = 0;
193 } else if (sta->tx_num_consecutive_failures >=
194 RATE_CONTROL_EMERG_DEC) {
195 rate_control_rate_dec(local, sta);
198 if (srctrl->avg_rate_update + 60 * HZ < jiffies) {
199 srctrl->avg_rate_update = jiffies;
200 if (srctrl->tx_avg_rate_num > 0) {
201 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
202 printk(KERN_DEBUG "%s: STA " MAC_FMT " Average rate: "
204 dev->name, MAC_ARG(sta->addr),
205 srctrl->tx_avg_rate_sum /
206 srctrl->tx_avg_rate_num,
207 srctrl->tx_avg_rate_sum,
208 srctrl->tx_avg_rate_num);
209 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
210 srctrl->tx_avg_rate_sum = 0;
211 srctrl->tx_avg_rate_num = 0;
219 static struct ieee80211_rate *
220 rate_control_simple_get_rate(void *priv, struct net_device *dev,
222 struct rate_control_extra *extra)
224 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
225 struct ieee80211_sub_if_data *sdata;
226 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
227 struct ieee80211_hw_mode *mode = extra->mode;
228 struct sta_info *sta;
229 int rateidx, nonerp_idx;
232 memset(extra, 0, sizeof(*extra));
234 fc = le16_to_cpu(hdr->frame_control);
235 if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
236 (hdr->addr1[0] & 0x01)) {
237 /* Send management frames and broadcast/multicast data using
239 /* TODO: this could probably be improved.. */
240 return rate_control_lowest_rate(local, mode);
243 sta = sta_info_get(local, hdr->addr1);
246 return rate_control_lowest_rate(local, mode);
248 sdata = IEEE80211_DEV_TO_SUB_IF(dev);
249 if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
250 sta->txrate = sdata->bss->force_unicast_rateidx;
252 rateidx = sta->txrate;
254 if (rateidx >= mode->num_rates)
255 rateidx = mode->num_rates - 1;
257 sta->last_txrate = rateidx;
258 nonerp_idx = rateidx;
259 while (nonerp_idx > 0 &&
260 ((mode->rates[nonerp_idx].flags & IEEE80211_RATE_ERP) ||
261 !(mode->rates[nonerp_idx].flags & IEEE80211_RATE_SUPPORTED) ||
262 !(sta->supp_rates & BIT(nonerp_idx))))
264 extra->nonerp = &mode->rates[nonerp_idx];
268 return &mode->rates[rateidx];
272 static void rate_control_simple_rate_init(void *priv, void *priv_sta,
273 struct ieee80211_local *local,
274 struct sta_info *sta)
276 struct ieee80211_hw_mode *mode;
279 mode = local->oper_hw_mode;
280 /* TODO: what is a good starting rate for STA? About middle? Maybe not
281 * the lowest or the highest rate.. Could consider using RSSI from
282 * previous packets? Need to have IEEE 802.1X auth succeed immediately
284 for (i = 0; i < mode->num_rates; i++) {
285 if ((sta->supp_rates & BIT(i)) &&
286 (mode->rates[i].flags & IEEE80211_RATE_SUPPORTED))
292 static void * rate_control_simple_alloc(struct ieee80211_local *local)
294 struct global_rate_control *rctrl;
296 rctrl = kzalloc(sizeof(*rctrl), GFP_ATOMIC);
302 static void rate_control_simple_free(void *priv)
304 struct global_rate_control *rctrl = priv;
309 static void rate_control_simple_clear(void *priv)
314 static void * rate_control_simple_alloc_sta(void *priv, gfp_t gfp)
316 struct sta_rate_control *rctrl;
318 rctrl = kzalloc(sizeof(*rctrl), gfp);
324 static void rate_control_simple_free_sta(void *priv, void *priv_sta)
326 struct sta_rate_control *rctrl = priv_sta;
331 static struct rate_control_ops rate_control_simple = {
332 .module = THIS_MODULE,
334 .tx_status = rate_control_simple_tx_status,
335 .get_rate = rate_control_simple_get_rate,
336 .rate_init = rate_control_simple_rate_init,
337 .clear = rate_control_simple_clear,
338 .alloc = rate_control_simple_alloc,
339 .free = rate_control_simple_free,
340 .alloc_sta = rate_control_simple_alloc_sta,
341 .free_sta = rate_control_simple_free_sta,
345 static int __init rate_control_simple_init(void)
347 return ieee80211_rate_control_register(&rate_control_simple);
351 static void __exit rate_control_simple_exit(void)
353 ieee80211_rate_control_unregister(&rate_control_simple);
357 module_init(rate_control_simple_init);
358 module_exit(rate_control_simple_exit);
360 MODULE_DESCRIPTION("Simple rate control algorithm for ieee80211");
361 MODULE_LICENSE("GPL");