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* Copyright 2002-2005, Instant802 Networks, Inc.
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* Copyright 2005, Devicescape Software, Inc.
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/netdevice.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/skbuff.h>
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#include <linux/compiler.h>
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#include <net/mac80211.h>
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#include "ieee80211_i.h"
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#include "ieee80211_rate.h"
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/* This is a minimal implementation of TX rate controlling that can be used
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* as the default when no improved mechanisms are available. */
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#define RATE_CONTROL_EMERG_DEC 2
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#define RATE_CONTROL_INTERVAL (HZ / 20)
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#define RATE_CONTROL_MIN_TX 10
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MODULE_ALIAS("rc80211_default");
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static void rate_control_rate_inc(struct ieee80211_local *local,
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struct ieee80211_sub_if_data *sdata;
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struct ieee80211_hw_mode *mode;
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sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
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if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
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/* forced unicast rate - do not change STA rate */
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mode = local->oper_hw_mode;
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maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
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if (i > mode->num_rates)
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i = mode->num_rates - 2;
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while (i + 1 < mode->num_rates) {
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if (sta->supp_rates & BIT(i) &&
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mode->rates[i].flags & IEEE80211_RATE_SUPPORTED &&
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(maxrate < 0 || i <= maxrate)) {
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static void rate_control_rate_dec(struct ieee80211_local *local,
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struct ieee80211_sub_if_data *sdata;
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struct ieee80211_hw_mode *mode;
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sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
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if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
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/* forced unicast rate - do not change STA rate */
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mode = local->oper_hw_mode;
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if (i > mode->num_rates)
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if (sta->supp_rates & BIT(i) &&
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mode->rates[i].flags & IEEE80211_RATE_SUPPORTED) {
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static struct ieee80211_rate *
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rate_control_lowest_rate(struct ieee80211_local *local,
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struct ieee80211_hw_mode *mode)
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for (i = 0; i < mode->num_rates; i++) {
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struct ieee80211_rate *rate = &mode->rates[i];
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if (rate->flags & IEEE80211_RATE_SUPPORTED)
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printk(KERN_DEBUG "rate_control_lowest_rate - no supported rates "
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return &mode->rates[0];
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struct global_rate_control {
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struct sta_rate_control {
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unsigned long last_rate_change;
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unsigned long avg_rate_update;
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#ifdef CONFIG_MAC80211_DEBUGFS
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struct dentry *tx_avg_rate_sum_dentry;
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struct dentry *tx_avg_rate_num_dentry;
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static void rate_control_simple_tx_status(void *priv, struct net_device *dev,
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struct iwlwifi_ieee80211_tx_status *status)
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struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
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struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
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struct sta_info *sta;
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struct sta_rate_control *srctrl;
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sta = iwlwifi_sta_info_get(local, hdr->addr1);
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srctrl = sta->rate_ctrl_priv;
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srctrl->tx_num_xmit++;
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if (status->excessive_retries) {
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sta->antenna_sel_tx = sta->antenna_sel_tx == 1 ? 2 : 1;
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sta->antenna_sel_rx = sta->antenna_sel_rx == 1 ? 2 : 1;
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if (local->sta_antenna_sel == STA_ANTENNA_SEL_SW_CTRL_DEBUG) {
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printk(KERN_DEBUG "%s: " MAC_FMT " TX antenna --> %d "
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"RX antenna --> %d (@%lu)\n",
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dev->name, MAC_ARG(hdr->addr1),
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sta->antenna_sel_tx, sta->antenna_sel_rx, jiffies);
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srctrl->tx_num_failures++;
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sta->tx_retry_failed++;
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sta->tx_num_consecutive_failures++;
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sta->tx_num_mpdu_fail++;
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sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
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sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
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sta->last_ack_rssi[2] = status->ack_signal;
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sta->tx_num_consecutive_failures = 0;
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sta->tx_num_mpdu_ok++;
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sta->tx_retry_count += status->retry_count;
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sta->tx_num_mpdu_fail += status->retry_count;
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if (time_after(jiffies,
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srctrl->last_rate_change + RATE_CONTROL_INTERVAL) &&
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srctrl->tx_num_xmit > RATE_CONTROL_MIN_TX) {
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srctrl->last_rate_change = jiffies;
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per_failed = (100 * sta->tx_num_mpdu_fail) /
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(sta->tx_num_mpdu_fail + sta->tx_num_mpdu_ok);
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/* TODO: calculate average per_failed to make adjusting
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* parameters easier */
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if (net_ratelimit()) {
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printk(KERN_DEBUG "MPDU fail=%d ok=%d per_failed=%d\n",
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sta->tx_num_mpdu_fail, sta->tx_num_mpdu_ok,
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* XXX: Make these configurable once we have an
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* interface to the rate control algorithms
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if (per_failed > RATE_CONTROL_NUM_DOWN) {
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rate_control_rate_dec(local, sta);
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} else if (per_failed < RATE_CONTROL_NUM_UP) {
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rate_control_rate_inc(local, sta);
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srctrl->tx_avg_rate_sum += status->control.rate->rate;
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srctrl->tx_avg_rate_num++;
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srctrl->tx_num_failures = 0;
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srctrl->tx_num_xmit = 0;
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} else if (sta->tx_num_consecutive_failures >=
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RATE_CONTROL_EMERG_DEC) {
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rate_control_rate_dec(local, sta);
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if (srctrl->avg_rate_update + 60 * HZ < jiffies) {
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srctrl->avg_rate_update = jiffies;
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if (srctrl->tx_avg_rate_num > 0) {
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#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
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printk(KERN_DEBUG "%s: STA " MAC_FMT " Average rate: "
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dev->name, MAC_ARG(sta->addr),
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srctrl->tx_avg_rate_sum /
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srctrl->tx_avg_rate_num,
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srctrl->tx_avg_rate_sum,
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srctrl->tx_avg_rate_num);
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#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
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srctrl->tx_avg_rate_sum = 0;
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srctrl->tx_avg_rate_num = 0;
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iwlwifi_sta_info_put(sta);
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static struct ieee80211_rate *
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rate_control_simple_get_rate(void *priv, struct net_device *dev,
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struct rate_control_extra *extra)
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struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
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struct ieee80211_sub_if_data *sdata;
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struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
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struct ieee80211_hw_mode *mode = extra->mode;
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struct sta_info *sta;
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int rateidx, nonerp_idx;
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memset(extra, 0, sizeof(*extra));
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fc = le16_to_cpu(hdr->frame_control);
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if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
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(hdr->addr1[0] & 0x01)) {
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/* Send management frames and broadcast/multicast data using
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/* TODO: this could probably be improved.. */
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return rate_control_lowest_rate(local, mode);
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sta = iwlwifi_sta_info_get(local, hdr->addr1);
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return rate_control_lowest_rate(local, mode);
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sdata = IEEE80211_DEV_TO_SUB_IF(dev);
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if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
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sta->txrate = sdata->bss->force_unicast_rateidx;
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rateidx = sta->txrate;
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if (rateidx >= mode->num_rates)
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rateidx = mode->num_rates - 1;
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sta->last_txrate = rateidx;
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nonerp_idx = rateidx;
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while (nonerp_idx > 0 &&
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((mode->rates[nonerp_idx].flags & IEEE80211_RATE_ERP) ||
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!(mode->rates[nonerp_idx].flags & IEEE80211_RATE_SUPPORTED) ||
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!(sta->supp_rates & BIT(nonerp_idx))))
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extra->nonerp = &mode->rates[nonerp_idx];
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iwlwifi_sta_info_put(sta);
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return &mode->rates[rateidx];
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static void rate_control_simple_rate_init(void *priv, void *priv_sta,
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struct ieee80211_local *local,
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struct sta_info *sta)
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struct ieee80211_hw_mode *mode;
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mode = local->oper_hw_mode;
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/* TODO: This routine should consider using RSSI from previous packets
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* as we need to have IEEE 802.1X auth succeed immediately after assoc..
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* Until that method is implemented, we will use the lowest supported rate
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* as a workaround, */
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for (i = 0; i < mode->num_rates; i++) {
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if ((sta->supp_rates & BIT(i)) &&
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(mode->rates[i].flags & IEEE80211_RATE_SUPPORTED)) {
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static void * rate_control_simple_alloc(struct ieee80211_local *local)
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struct global_rate_control *rctrl;
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rctrl = kzalloc(sizeof(*rctrl), GFP_ATOMIC);
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static void rate_control_simple_free(void *priv)
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struct global_rate_control *rctrl = priv;
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static void rate_control_simple_clear(void *priv)
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static void * rate_control_simple_alloc_sta(void *priv, gfp_t gfp)
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struct sta_rate_control *rctrl;
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rctrl = kzalloc(sizeof(*rctrl), gfp);
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static void rate_control_simple_free_sta(void *priv, void *priv_sta)
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struct sta_rate_control *rctrl = priv_sta;
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#ifdef CONFIG_MAC80211_DEBUGFS
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static int open_file_generic(struct inode *inode, struct file *file)
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file->private_data = inode->i_private;
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static ssize_t sta_tx_avg_rate_sum_read(struct file *file,
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char __user *userbuf,
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size_t count, loff_t *ppos)
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struct sta_rate_control *srctrl = file->private_data;
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sprintf(buf, "%d\n", srctrl->tx_avg_rate_sum);
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return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
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static const struct file_operations sta_tx_avg_rate_sum_ops = {
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.read = sta_tx_avg_rate_sum_read,
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.open = open_file_generic,
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static ssize_t sta_tx_avg_rate_num_read(struct file *file,
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char __user *userbuf,
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size_t count, loff_t *ppos)
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struct sta_rate_control *srctrl = file->private_data;
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sprintf(buf, "%d\n", srctrl->tx_avg_rate_num);
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return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
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static const struct file_operations sta_tx_avg_rate_num_ops = {
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.read = sta_tx_avg_rate_num_read,
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.open = open_file_generic,
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static void rate_control_simple_add_sta_debugfs(void *priv, void *priv_sta,
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struct sta_rate_control *srctrl = priv_sta;
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srctrl->tx_avg_rate_num_dentry =
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debugfs_create_file("rc_simple_sta_tx_avg_rate_num", 0400,
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dir, srctrl, &sta_tx_avg_rate_num_ops);
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srctrl->tx_avg_rate_sum_dentry =
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debugfs_create_file("rc_simple_sta_tx_avg_rate_sum", 0400,
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dir, srctrl, &sta_tx_avg_rate_sum_ops);
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static void rate_control_simple_remove_sta_debugfs(void *priv, void *priv_sta)
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struct sta_rate_control *srctrl = priv_sta;
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debugfs_remove(srctrl->tx_avg_rate_sum_dentry);
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debugfs_remove(srctrl->tx_avg_rate_num_dentry);
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static struct rate_control_ops rate_control_simple = {
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.module = THIS_MODULE,
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.tx_status = rate_control_simple_tx_status,
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.get_rate = rate_control_simple_get_rate,
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.rate_init = rate_control_simple_rate_init,
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.clear = rate_control_simple_clear,
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.alloc = rate_control_simple_alloc,
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.free = rate_control_simple_free,
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.alloc_sta = rate_control_simple_alloc_sta,
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.free_sta = rate_control_simple_free_sta,
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#ifdef CONFIG_MAC80211_DEBUGFS
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.add_sta_debugfs = rate_control_simple_add_sta_debugfs,
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.remove_sta_debugfs = rate_control_simple_remove_sta_debugfs,
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static int __init rate_control_simple_init(void)
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return iwlwifi_ieee80211_rate_control_register(&rate_control_simple);
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static void __exit rate_control_simple_exit(void)
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iwlwifi_ieee80211_rate_control_unregister(&rate_control_simple);
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module_init(rate_control_simple_init);
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module_exit(rate_control_simple_exit);
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MODULE_DESCRIPTION("Simple rate control algorithm for ieee80211");
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MODULE_LICENSE("GPL");