Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2002-2005, Instant802 Networks, Inc. |
| 3 | * Copyright 2005, Devicescape Software, Inc. |
| 4 | * Copyright 2007, Mattias Nissler <mattias.nissler@gmx.de> |
Stefano Brivio | b7c50de9 | 2008-01-29 20:29:16 +0100 | [diff] [blame^] | 5 | * Copyright 2007-2008, Stefano Brivio <stefano.brivio@polimi.it> |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/netdevice.h> |
| 13 | #include <linux/types.h> |
| 14 | #include <linux/skbuff.h> |
Johannes Berg | 4b47589 | 2008-01-02 15:17:03 +0100 | [diff] [blame] | 15 | #include <linux/debugfs.h> |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 16 | #include <net/mac80211.h> |
| 17 | #include "ieee80211_rate.h" |
| 18 | |
Mattias Nissler | 12446c6 | 2007-12-19 01:27:18 +0100 | [diff] [blame] | 19 | #include "rc80211_pid.h" |
| 20 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 21 | |
| 22 | /* This is an implementation of a TX rate control algorithm that uses a PID |
| 23 | * controller. Given a target failed frames rate, the controller decides about |
| 24 | * TX rate changes to meet the target failed frames rate. |
| 25 | * |
| 26 | * The controller basically computes the following: |
| 27 | * |
Stefano Brivio | 1dc4d1e | 2007-12-19 01:26:52 +0100 | [diff] [blame] | 28 | * adj = CP * err + CI * err_avg + CD * (err - last_err) * (1 + sharpening) |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 29 | * |
| 30 | * where |
| 31 | * adj adjustment value that is used to switch TX rate (see below) |
| 32 | * err current error: target vs. current failed frames percentage |
| 33 | * last_err last error |
| 34 | * err_avg average (i.e. poor man's integral) of recent errors |
Stefano Brivio | 1dc4d1e | 2007-12-19 01:26:52 +0100 | [diff] [blame] | 35 | * sharpening non-zero when fast response is needed (i.e. right after |
| 36 | * association or no frames sent for a long time), heading |
| 37 | * to zero over time |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 38 | * CP Proportional coefficient |
| 39 | * CI Integral coefficient |
| 40 | * CD Derivative coefficient |
| 41 | * |
| 42 | * CP, CI, CD are subject to careful tuning. |
| 43 | * |
| 44 | * The integral component uses a exponential moving average approach instead of |
| 45 | * an actual sliding window. The advantage is that we don't need to keep an |
| 46 | * array of the last N error values and computation is easier. |
| 47 | * |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 48 | * Once we have the adj value, we map it to a rate by means of a learning |
| 49 | * algorithm. This algorithm keeps the state of the percentual failed frames |
| 50 | * difference between rates. The behaviour of the lowest available rate is kept |
| 51 | * as a reference value, and every time we switch between two rates, we compute |
| 52 | * the difference between the failed frames each rate exhibited. By doing so, |
| 53 | * we compare behaviours which different rates exhibited in adjacent timeslices, |
| 54 | * thus the comparison is minimally affected by external conditions. This |
| 55 | * difference gets propagated to the whole set of measurements, so that the |
| 56 | * reference is always the same. Periodically, we normalize this set so that |
| 57 | * recent events weigh the most. By comparing the adj value with this set, we |
| 58 | * avoid pejorative switches to lower rates and allow for switches to higher |
| 59 | * rates if they behaved well. |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 60 | * |
| 61 | * Note that for the computations we use a fixed-point representation to avoid |
| 62 | * floating point arithmetic. Hence, all values are shifted left by |
| 63 | * RC_PID_ARITH_SHIFT. |
| 64 | */ |
| 65 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 66 | |
Stefano Brivio | b7c50de9 | 2008-01-29 20:29:16 +0100 | [diff] [blame^] | 67 | /* Adjust the rate while ensuring that we won't switch to a lower rate if it |
| 68 | * exhibited a worse failed frames behaviour and we'll choose the highest rate |
| 69 | * whose failed frames behaviour is not worse than the one of the original rate |
| 70 | * target. While at it, check that the new rate is valid. */ |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 71 | static void rate_control_pid_adjust_rate(struct ieee80211_local *local, |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 72 | struct sta_info *sta, int adj, |
| 73 | struct rc_pid_rateinfo *rinfo) |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 74 | { |
| 75 | struct ieee80211_sub_if_data *sdata; |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 76 | struct ieee80211_supported_band *sband; |
Stefano Brivio | b7c50de9 | 2008-01-29 20:29:16 +0100 | [diff] [blame^] | 77 | int cur_sorted, new_sorted, probe, tmp, n_bitrates, band; |
| 78 | int cur = sta->txrate_idx; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 79 | |
| 80 | sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev); |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 81 | sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; |
Stefano Brivio | b7c50de9 | 2008-01-29 20:29:16 +0100 | [diff] [blame^] | 82 | band = sband->band; |
| 83 | n_bitrates = sband->n_bitrates; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 84 | |
Stefano Brivio | b7c50de9 | 2008-01-29 20:29:16 +0100 | [diff] [blame^] | 85 | /* Map passed arguments to sorted values. */ |
| 86 | cur_sorted = rinfo[cur].rev_index; |
| 87 | new_sorted = cur_sorted + adj; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 88 | |
Stefano Brivio | b7c50de9 | 2008-01-29 20:29:16 +0100 | [diff] [blame^] | 89 | /* Check limits. */ |
| 90 | if (new_sorted < 0) |
| 91 | new_sorted = rinfo[0].rev_index; |
| 92 | else if (new_sorted >= n_bitrates) |
| 93 | new_sorted = rinfo[n_bitrates - 1].rev_index; |
| 94 | |
| 95 | tmp = new_sorted; |
| 96 | |
| 97 | if (adj < 0) { |
| 98 | /* Ensure that the rate decrease isn't disadvantageous. */ |
| 99 | for (probe = cur_sorted; probe >= new_sorted; probe--) |
| 100 | if (rinfo[probe].diff <= rinfo[cur_sorted].diff && |
| 101 | rate_supported(sta, band, rinfo[probe].index)) |
| 102 | tmp = probe; |
| 103 | } else { |
| 104 | /* Look for rate increase with zero (or below) cost. */ |
| 105 | for (probe = new_sorted + 1; probe < n_bitrates; probe++) |
| 106 | if (rinfo[probe].diff <= rinfo[new_sorted].diff && |
| 107 | rate_supported(sta, band, rinfo[probe].index)) |
| 108 | tmp = probe; |
| 109 | } |
| 110 | |
| 111 | /* Fit the rate found to the nearest supported rate. */ |
| 112 | do { |
| 113 | if (rate_supported(sta, band, rinfo[tmp].index)) { |
| 114 | sta->txrate_idx = rinfo[tmp].index; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 115 | break; |
| 116 | } |
Stefano Brivio | b7c50de9 | 2008-01-29 20:29:16 +0100 | [diff] [blame^] | 117 | if (adj < 0) |
| 118 | tmp--; |
| 119 | else |
| 120 | tmp++; |
| 121 | } while (tmp < n_bitrates && tmp >= 0); |
Mattias Nissler | 12446c6 | 2007-12-19 01:27:18 +0100 | [diff] [blame] | 122 | |
| 123 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 124 | rate_control_pid_event_rate_change( |
| 125 | &((struct rc_pid_sta_info *)sta->rate_ctrl_priv)->events, |
Stefano Brivio | b7c50de9 | 2008-01-29 20:29:16 +0100 | [diff] [blame^] | 126 | sta->txrate_idx, sband->bitrates[sta->txrate_idx].bitrate); |
Mattias Nissler | 12446c6 | 2007-12-19 01:27:18 +0100 | [diff] [blame] | 127 | #endif |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 128 | } |
| 129 | |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 130 | /* Normalize the failed frames per-rate differences. */ |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 131 | static void rate_control_pid_normalize(struct rc_pid_info *pinfo, int l) |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 132 | { |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 133 | int i, norm_offset = pinfo->norm_offset; |
| 134 | struct rc_pid_rateinfo *r = pinfo->rinfo; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 135 | |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 136 | if (r[0].diff > norm_offset) |
| 137 | r[0].diff -= norm_offset; |
| 138 | else if (r[0].diff < -norm_offset) |
| 139 | r[0].diff += norm_offset; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 140 | for (i = 0; i < l - 1; i++) |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 141 | if (r[i + 1].diff > r[i].diff + norm_offset) |
| 142 | r[i + 1].diff -= norm_offset; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 143 | else if (r[i + 1].diff <= r[i].diff) |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 144 | r[i + 1].diff += norm_offset; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 145 | } |
| 146 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 147 | static void rate_control_pid_sample(struct rc_pid_info *pinfo, |
| 148 | struct ieee80211_local *local, |
| 149 | struct sta_info *sta) |
| 150 | { |
| 151 | struct rc_pid_sta_info *spinfo = sta->rate_ctrl_priv; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 152 | struct rc_pid_rateinfo *rinfo = pinfo->rinfo; |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 153 | struct ieee80211_supported_band *sband; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 154 | u32 pf; |
| 155 | s32 err_avg; |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 156 | u32 err_prop; |
| 157 | u32 err_int; |
| 158 | u32 err_der; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 159 | int adj, i, j, tmp; |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 160 | unsigned long period; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 161 | |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 162 | sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 163 | spinfo = sta->rate_ctrl_priv; |
Stefano Brivio | 1dc4d1e | 2007-12-19 01:26:52 +0100 | [diff] [blame] | 164 | |
| 165 | /* In case nothing happened during the previous control interval, turn |
| 166 | * the sharpening factor on. */ |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 167 | period = (HZ * pinfo->sampling_period + 500) / 1000; |
| 168 | if (!period) |
| 169 | period = 1; |
| 170 | if (jiffies - spinfo->last_sample > 2 * period) |
| 171 | spinfo->sharp_cnt = pinfo->sharpen_duration; |
Stefano Brivio | 1dc4d1e | 2007-12-19 01:26:52 +0100 | [diff] [blame] | 172 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 173 | spinfo->last_sample = jiffies; |
| 174 | |
Stefano Brivio | 1dc4d1e | 2007-12-19 01:26:52 +0100 | [diff] [blame] | 175 | /* This should never happen, but in case, we assume the old sample is |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 176 | * still a good measurement and copy it. */ |
Stefano Brivio | 1dc4d1e | 2007-12-19 01:26:52 +0100 | [diff] [blame] | 177 | if (unlikely(spinfo->tx_num_xmit == 0)) |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 178 | pf = spinfo->last_pf; |
| 179 | else { |
| 180 | pf = spinfo->tx_num_failed * 100 / spinfo->tx_num_xmit; |
| 181 | pf <<= RC_PID_ARITH_SHIFT; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 182 | } |
| 183 | |
Stefano Brivio | 1dc4d1e | 2007-12-19 01:26:52 +0100 | [diff] [blame] | 184 | spinfo->tx_num_xmit = 0; |
| 185 | spinfo->tx_num_failed = 0; |
| 186 | |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 187 | /* If we just switched rate, update the rate behaviour info. */ |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 188 | if (pinfo->oldrate != sta->txrate_idx) { |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 189 | |
| 190 | i = rinfo[pinfo->oldrate].rev_index; |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 191 | j = rinfo[sta->txrate_idx].rev_index; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 192 | |
| 193 | tmp = (pf - spinfo->last_pf); |
| 194 | tmp = RC_PID_DO_ARITH_RIGHT_SHIFT(tmp, RC_PID_ARITH_SHIFT); |
| 195 | |
| 196 | rinfo[j].diff = rinfo[i].diff + tmp; |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 197 | pinfo->oldrate = sta->txrate_idx; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 198 | } |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 199 | rate_control_pid_normalize(pinfo, sband->n_bitrates); |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 200 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 201 | /* Compute the proportional, integral and derivative errors. */ |
Stefano Brivio | 426706c | 2007-12-23 04:39:17 +0100 | [diff] [blame] | 202 | err_prop = (pinfo->target << RC_PID_ARITH_SHIFT) - pf; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 203 | |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 204 | err_avg = spinfo->err_avg_sc >> pinfo->smoothing_shift; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 205 | spinfo->err_avg_sc = spinfo->err_avg_sc - err_avg + err_prop; |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 206 | err_int = spinfo->err_avg_sc >> pinfo->smoothing_shift; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 207 | |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 208 | err_der = (pf - spinfo->last_pf) * |
| 209 | (1 + pinfo->sharpen_factor * spinfo->sharp_cnt); |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 210 | spinfo->last_pf = pf; |
Stefano Brivio | 1dc4d1e | 2007-12-19 01:26:52 +0100 | [diff] [blame] | 211 | if (spinfo->sharp_cnt) |
| 212 | spinfo->sharp_cnt--; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 213 | |
Mattias Nissler | 12446c6 | 2007-12-19 01:27:18 +0100 | [diff] [blame] | 214 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 215 | rate_control_pid_event_pf_sample(&spinfo->events, pf, err_prop, err_int, |
| 216 | err_der); |
| 217 | #endif |
| 218 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 219 | /* Compute the controller output. */ |
| 220 | adj = (err_prop * pinfo->coeff_p + err_int * pinfo->coeff_i |
| 221 | + err_der * pinfo->coeff_d); |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 222 | adj = RC_PID_DO_ARITH_RIGHT_SHIFT(adj, 2 * RC_PID_ARITH_SHIFT); |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 223 | |
| 224 | /* Change rate. */ |
| 225 | if (adj) |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 226 | rate_control_pid_adjust_rate(local, sta, adj, rinfo); |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 227 | } |
| 228 | |
| 229 | static void rate_control_pid_tx_status(void *priv, struct net_device *dev, |
| 230 | struct sk_buff *skb, |
| 231 | struct ieee80211_tx_status *status) |
| 232 | { |
| 233 | struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); |
| 234 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; |
Andrew Lutomirski | df26e7e | 2008-01-03 21:05:37 -0800 | [diff] [blame] | 235 | struct ieee80211_sub_if_data *sdata; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 236 | struct rc_pid_info *pinfo = priv; |
| 237 | struct sta_info *sta; |
| 238 | struct rc_pid_sta_info *spinfo; |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 239 | unsigned long period; |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 240 | struct ieee80211_supported_band *sband; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 241 | |
| 242 | sta = sta_info_get(local, hdr->addr1); |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 243 | sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 244 | |
| 245 | if (!sta) |
| 246 | return; |
| 247 | |
Andrew Lutomirski | df26e7e | 2008-01-03 21:05:37 -0800 | [diff] [blame] | 248 | /* Don't update the state if we're not controlling the rate. */ |
| 249 | sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev); |
| 250 | if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) { |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 251 | sta->txrate_idx = sdata->bss->max_ratectrl_rateidx; |
Andrew Lutomirski | df26e7e | 2008-01-03 21:05:37 -0800 | [diff] [blame] | 252 | return; |
| 253 | } |
| 254 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 255 | /* Ignore all frames that were sent with a different rate than the rate |
| 256 | * we currently advise mac80211 to use. */ |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 257 | if (status->control.tx_rate != &sband->bitrates[sta->txrate_idx]) |
Stefano Brivio | 13e05aa | 2007-12-23 04:43:57 +0100 | [diff] [blame] | 258 | goto ignore; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 259 | |
| 260 | spinfo = sta->rate_ctrl_priv; |
| 261 | spinfo->tx_num_xmit++; |
| 262 | |
Mattias Nissler | 12446c6 | 2007-12-19 01:27:18 +0100 | [diff] [blame] | 263 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 264 | rate_control_pid_event_tx_status(&spinfo->events, status); |
| 265 | #endif |
| 266 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 267 | /* We count frames that totally failed to be transmitted as two bad |
| 268 | * frames, those that made it out but had some retries as one good and |
| 269 | * one bad frame. */ |
| 270 | if (status->excessive_retries) { |
| 271 | spinfo->tx_num_failed += 2; |
| 272 | spinfo->tx_num_xmit++; |
| 273 | } else if (status->retry_count) { |
| 274 | spinfo->tx_num_failed++; |
| 275 | spinfo->tx_num_xmit++; |
| 276 | } |
| 277 | |
| 278 | if (status->excessive_retries) { |
| 279 | sta->tx_retry_failed++; |
| 280 | sta->tx_num_consecutive_failures++; |
| 281 | sta->tx_num_mpdu_fail++; |
| 282 | } else { |
| 283 | sta->last_ack_rssi[0] = sta->last_ack_rssi[1]; |
| 284 | sta->last_ack_rssi[1] = sta->last_ack_rssi[2]; |
| 285 | sta->last_ack_rssi[2] = status->ack_signal; |
| 286 | sta->tx_num_consecutive_failures = 0; |
| 287 | sta->tx_num_mpdu_ok++; |
| 288 | } |
| 289 | sta->tx_retry_count += status->retry_count; |
| 290 | sta->tx_num_mpdu_fail += status->retry_count; |
| 291 | |
| 292 | /* Update PID controller state. */ |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 293 | period = (HZ * pinfo->sampling_period + 500) / 1000; |
| 294 | if (!period) |
| 295 | period = 1; |
| 296 | if (time_after(jiffies, spinfo->last_sample + period)) |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 297 | rate_control_pid_sample(pinfo, local, sta); |
| 298 | |
Stefano Brivio | 13e05aa | 2007-12-23 04:43:57 +0100 | [diff] [blame] | 299 | ignore: |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 300 | sta_info_put(sta); |
| 301 | } |
| 302 | |
| 303 | static void rate_control_pid_get_rate(void *priv, struct net_device *dev, |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 304 | struct ieee80211_supported_band *sband, |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 305 | struct sk_buff *skb, |
| 306 | struct rate_selection *sel) |
| 307 | { |
| 308 | struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); |
| 309 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; |
Michael Wu | 2bc454b | 2007-12-25 19:33:16 -0500 | [diff] [blame] | 310 | struct ieee80211_sub_if_data *sdata; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 311 | struct sta_info *sta; |
| 312 | int rateidx; |
Michael Wu | 2bc454b | 2007-12-25 19:33:16 -0500 | [diff] [blame] | 313 | u16 fc; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 314 | |
| 315 | sta = sta_info_get(local, hdr->addr1); |
| 316 | |
Michael Wu | 2bc454b | 2007-12-25 19:33:16 -0500 | [diff] [blame] | 317 | /* Send management frames and broadcast/multicast data using lowest |
| 318 | * rate. */ |
| 319 | fc = le16_to_cpu(hdr->frame_control); |
| 320 | if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA || |
| 321 | is_multicast_ether_addr(hdr->addr1) || !sta) { |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 322 | sel->rate = rate_lowest(local, sband, sta); |
Michael Wu | 2bc454b | 2007-12-25 19:33:16 -0500 | [diff] [blame] | 323 | if (sta) |
| 324 | sta_info_put(sta); |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 325 | return; |
| 326 | } |
| 327 | |
Michael Wu | 2bc454b | 2007-12-25 19:33:16 -0500 | [diff] [blame] | 328 | /* If a forced rate is in effect, select it. */ |
| 329 | sdata = IEEE80211_DEV_TO_SUB_IF(dev); |
| 330 | if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 331 | sta->txrate_idx = sdata->bss->force_unicast_rateidx; |
Michael Wu | 2bc454b | 2007-12-25 19:33:16 -0500 | [diff] [blame] | 332 | |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 333 | rateidx = sta->txrate_idx; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 334 | |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 335 | if (rateidx >= sband->n_bitrates) |
| 336 | rateidx = sband->n_bitrates - 1; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 337 | |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 338 | sta->last_txrate_idx = rateidx; |
Michael Wu | 2bc454b | 2007-12-25 19:33:16 -0500 | [diff] [blame] | 339 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 340 | sta_info_put(sta); |
| 341 | |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 342 | sel->rate = &sband->bitrates[rateidx]; |
Mattias Nissler | 12446c6 | 2007-12-19 01:27:18 +0100 | [diff] [blame] | 343 | |
| 344 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 345 | rate_control_pid_event_tx_rate( |
| 346 | &((struct rc_pid_sta_info *) sta->rate_ctrl_priv)->events, |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 347 | rateidx, sband->bitrates[rateidx].bitrate); |
Mattias Nissler | 12446c6 | 2007-12-19 01:27:18 +0100 | [diff] [blame] | 348 | #endif |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 349 | } |
| 350 | |
| 351 | static void rate_control_pid_rate_init(void *priv, void *priv_sta, |
| 352 | struct ieee80211_local *local, |
| 353 | struct sta_info *sta) |
| 354 | { |
| 355 | /* TODO: This routine should consider using RSSI from previous packets |
| 356 | * as we need to have IEEE 802.1X auth succeed immediately after assoc.. |
| 357 | * Until that method is implemented, we will use the lowest supported |
| 358 | * rate as a workaround. */ |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 359 | struct ieee80211_supported_band *sband; |
| 360 | |
| 361 | sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; |
| 362 | sta->txrate_idx = rate_lowest_index(local, sband, sta); |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 363 | } |
| 364 | |
| 365 | static void *rate_control_pid_alloc(struct ieee80211_local *local) |
| 366 | { |
| 367 | struct rc_pid_info *pinfo; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 368 | struct rc_pid_rateinfo *rinfo; |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 369 | struct ieee80211_supported_band *sband; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 370 | int i, j, tmp; |
| 371 | bool s; |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 372 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 373 | struct rc_pid_debugfs_entries *de; |
| 374 | #endif |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 375 | |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 376 | sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; |
| 377 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 378 | pinfo = kmalloc(sizeof(*pinfo), GFP_ATOMIC); |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 379 | if (!pinfo) |
| 380 | return NULL; |
| 381 | |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 382 | /* We can safely assume that sband won't change unless we get |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 383 | * reinitialized. */ |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 384 | rinfo = kmalloc(sizeof(*rinfo) * sband->n_bitrates, GFP_ATOMIC); |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 385 | if (!rinfo) { |
| 386 | kfree(pinfo); |
| 387 | return NULL; |
| 388 | } |
| 389 | |
| 390 | /* Sort the rates. This is optimized for the most common case (i.e. |
| 391 | * almost-sorted CCK+OFDM rates). Kind of bubble-sort with reversed |
| 392 | * mapping too. */ |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 393 | for (i = 0; i < sband->n_bitrates; i++) { |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 394 | rinfo[i].index = i; |
| 395 | rinfo[i].rev_index = i; |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 396 | if (pinfo->fast_start) |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 397 | rinfo[i].diff = 0; |
| 398 | else |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 399 | rinfo[i].diff = i * pinfo->norm_offset; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 400 | } |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 401 | for (i = 1; i < sband->n_bitrates; i++) { |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 402 | s = 0; |
Johannes Berg | 8318d78 | 2008-01-24 19:38:38 +0100 | [diff] [blame] | 403 | for (j = 0; j < sband->n_bitrates - i; j++) |
| 404 | if (unlikely(sband->bitrates[rinfo[j].index].bitrate > |
| 405 | sband->bitrates[rinfo[j + 1].index].bitrate)) { |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 406 | tmp = rinfo[j].index; |
| 407 | rinfo[j].index = rinfo[j + 1].index; |
| 408 | rinfo[j + 1].index = tmp; |
| 409 | rinfo[rinfo[j].index].rev_index = j; |
| 410 | rinfo[rinfo[j + 1].index].rev_index = j + 1; |
| 411 | s = 1; |
| 412 | } |
| 413 | if (!s) |
| 414 | break; |
| 415 | } |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 416 | |
| 417 | pinfo->target = RC_PID_TARGET_PF; |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 418 | pinfo->sampling_period = RC_PID_INTERVAL; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 419 | pinfo->coeff_p = RC_PID_COEFF_P; |
| 420 | pinfo->coeff_i = RC_PID_COEFF_I; |
| 421 | pinfo->coeff_d = RC_PID_COEFF_D; |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 422 | pinfo->smoothing_shift = RC_PID_SMOOTHING_SHIFT; |
| 423 | pinfo->sharpen_factor = RC_PID_SHARPENING_FACTOR; |
| 424 | pinfo->sharpen_duration = RC_PID_SHARPENING_DURATION; |
| 425 | pinfo->norm_offset = RC_PID_NORM_OFFSET; |
| 426 | pinfo->fast_start = RC_PID_FAST_START; |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 427 | pinfo->rinfo = rinfo; |
| 428 | pinfo->oldrate = 0; |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 429 | |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 430 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 431 | de = &pinfo->dentries; |
| 432 | de->dir = debugfs_create_dir("rc80211_pid", |
| 433 | local->hw.wiphy->debugfsdir); |
| 434 | de->target = debugfs_create_u32("target_pf", S_IRUSR | S_IWUSR, |
| 435 | de->dir, &pinfo->target); |
| 436 | de->sampling_period = debugfs_create_u32("sampling_period", |
| 437 | S_IRUSR | S_IWUSR, de->dir, |
| 438 | &pinfo->sampling_period); |
| 439 | de->coeff_p = debugfs_create_u32("coeff_p", S_IRUSR | S_IWUSR, |
| 440 | de->dir, &pinfo->coeff_p); |
| 441 | de->coeff_i = debugfs_create_u32("coeff_i", S_IRUSR | S_IWUSR, |
| 442 | de->dir, &pinfo->coeff_i); |
| 443 | de->coeff_d = debugfs_create_u32("coeff_d", S_IRUSR | S_IWUSR, |
| 444 | de->dir, &pinfo->coeff_d); |
| 445 | de->smoothing_shift = debugfs_create_u32("smoothing_shift", |
| 446 | S_IRUSR | S_IWUSR, de->dir, |
| 447 | &pinfo->smoothing_shift); |
| 448 | de->sharpen_factor = debugfs_create_u32("sharpen_factor", |
| 449 | S_IRUSR | S_IWUSR, de->dir, |
| 450 | &pinfo->sharpen_factor); |
| 451 | de->sharpen_duration = debugfs_create_u32("sharpen_duration", |
| 452 | S_IRUSR | S_IWUSR, de->dir, |
| 453 | &pinfo->sharpen_duration); |
| 454 | de->norm_offset = debugfs_create_u32("norm_offset", |
| 455 | S_IRUSR | S_IWUSR, de->dir, |
| 456 | &pinfo->norm_offset); |
| 457 | de->fast_start = debugfs_create_bool("fast_start", |
| 458 | S_IRUSR | S_IWUSR, de->dir, |
| 459 | &pinfo->fast_start); |
| 460 | #endif |
| 461 | |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 462 | return pinfo; |
| 463 | } |
| 464 | |
| 465 | static void rate_control_pid_free(void *priv) |
| 466 | { |
| 467 | struct rc_pid_info *pinfo = priv; |
Mattias Nissler | 1946b74 | 2007-12-20 13:27:26 +0100 | [diff] [blame] | 468 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 469 | struct rc_pid_debugfs_entries *de = &pinfo->dentries; |
| 470 | |
| 471 | debugfs_remove(de->fast_start); |
| 472 | debugfs_remove(de->norm_offset); |
| 473 | debugfs_remove(de->sharpen_duration); |
| 474 | debugfs_remove(de->sharpen_factor); |
| 475 | debugfs_remove(de->smoothing_shift); |
| 476 | debugfs_remove(de->coeff_d); |
| 477 | debugfs_remove(de->coeff_i); |
| 478 | debugfs_remove(de->coeff_p); |
| 479 | debugfs_remove(de->sampling_period); |
| 480 | debugfs_remove(de->target); |
| 481 | debugfs_remove(de->dir); |
| 482 | #endif |
| 483 | |
Stefano Brivio | 90d501d | 2007-12-19 01:26:34 +0100 | [diff] [blame] | 484 | kfree(pinfo->rinfo); |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 485 | kfree(pinfo); |
| 486 | } |
| 487 | |
| 488 | static void rate_control_pid_clear(void *priv) |
| 489 | { |
| 490 | } |
| 491 | |
| 492 | static void *rate_control_pid_alloc_sta(void *priv, gfp_t gfp) |
| 493 | { |
| 494 | struct rc_pid_sta_info *spinfo; |
| 495 | |
| 496 | spinfo = kzalloc(sizeof(*spinfo), gfp); |
Mattias Nissler | 12446c6 | 2007-12-19 01:27:18 +0100 | [diff] [blame] | 497 | if (spinfo == NULL) |
| 498 | return NULL; |
| 499 | |
Stefano Brivio | c09c723 | 2008-01-17 00:38:29 +0100 | [diff] [blame] | 500 | spinfo->last_sample = jiffies; |
| 501 | |
Mattias Nissler | 12446c6 | 2007-12-19 01:27:18 +0100 | [diff] [blame] | 502 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 503 | spin_lock_init(&spinfo->events.lock); |
| 504 | init_waitqueue_head(&spinfo->events.waitqueue); |
| 505 | #endif |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 506 | |
| 507 | return spinfo; |
| 508 | } |
| 509 | |
| 510 | static void rate_control_pid_free_sta(void *priv, void *priv_sta) |
| 511 | { |
| 512 | struct rc_pid_sta_info *spinfo = priv_sta; |
| 513 | kfree(spinfo); |
| 514 | } |
| 515 | |
Johannes Berg | 4b47589 | 2008-01-02 15:17:03 +0100 | [diff] [blame] | 516 | static struct rate_control_ops mac80211_rcpid = { |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 517 | .name = "pid", |
| 518 | .tx_status = rate_control_pid_tx_status, |
| 519 | .get_rate = rate_control_pid_get_rate, |
| 520 | .rate_init = rate_control_pid_rate_init, |
| 521 | .clear = rate_control_pid_clear, |
| 522 | .alloc = rate_control_pid_alloc, |
| 523 | .free = rate_control_pid_free, |
| 524 | .alloc_sta = rate_control_pid_alloc_sta, |
| 525 | .free_sta = rate_control_pid_free_sta, |
Mattias Nissler | 12446c6 | 2007-12-19 01:27:18 +0100 | [diff] [blame] | 526 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 527 | .add_sta_debugfs = rate_control_pid_add_sta_debugfs, |
| 528 | .remove_sta_debugfs = rate_control_pid_remove_sta_debugfs, |
| 529 | #endif |
Mattias Nissler | ad01837 | 2007-12-19 01:25:57 +0100 | [diff] [blame] | 530 | }; |
Johannes Berg | 4b47589 | 2008-01-02 15:17:03 +0100 | [diff] [blame] | 531 | |
| 532 | MODULE_DESCRIPTION("PID controller based rate control algorithm"); |
| 533 | MODULE_AUTHOR("Stefano Brivio"); |
| 534 | MODULE_AUTHOR("Mattias Nissler"); |
| 535 | MODULE_LICENSE("GPL"); |
| 536 | |
| 537 | int __init rc80211_pid_init(void) |
| 538 | { |
| 539 | return ieee80211_rate_control_register(&mac80211_rcpid); |
| 540 | } |
| 541 | |
Johannes Berg | f0b9205 | 2008-01-31 19:31:57 +0100 | [diff] [blame] | 542 | void rc80211_pid_exit(void) |
Johannes Berg | 4b47589 | 2008-01-02 15:17:03 +0100 | [diff] [blame] | 543 | { |
| 544 | ieee80211_rate_control_unregister(&mac80211_rcpid); |
| 545 | } |
| 546 | |
| 547 | #ifdef CONFIG_MAC80211_RC_PID_MODULE |
| 548 | module_init(rc80211_pid_init); |
| 549 | module_exit(rc80211_pid_exit); |
| 550 | #endif |