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linux/net/mac80211/rc80211_simple.c
Larry Finger eef6caf8a9 [MAC80211]: Set low initial rate in rc80211_simple 
The initial rate for STA's using rc80211_simple is set to the last
rate in the rate table. For situations for which the signal is weak,
the rate may be too high for authentication and association. Although
the rc80211_simple module will adjust the speed, the response may not
be fast enough for a successful connection. This modification sets the
initial rate to the lowest supported value.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-10 22:16:25 -07:00

435 lines
11 KiB
C
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/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005, Devicescape Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/compiler.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "ieee80211_rate.h"
#include "debugfs.h"
/* This is a minimal implementation of TX rate controlling that can be used
* as the default when no improved mechanisms are available. */
#define RATE_CONTROL_EMERG_DEC 2
#define RATE_CONTROL_INTERVAL (HZ / 20)
#define RATE_CONTROL_MIN_TX 10
MODULE_ALIAS("rc80211_default");
static void rate_control_rate_inc(struct ieee80211_local *local,
struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata;
struct ieee80211_hw_mode *mode;
int i = sta->txrate;
int maxrate;
sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
/* forced unicast rate - do not change STA rate */
return;
}
mode = local->oper_hw_mode;
maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
if (i > mode->num_rates)
i = mode->num_rates - 2;
while (i + 1 < mode->num_rates) {
i++;
if (sta->supp_rates & BIT(i) &&
mode->rates[i].flags & IEEE80211_RATE_SUPPORTED &&
(maxrate < 0 || i <= maxrate)) {
sta->txrate = i;
break;
}
}
}
static void rate_control_rate_dec(struct ieee80211_local *local,
struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata;
struct ieee80211_hw_mode *mode;
int i = sta->txrate;
sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
/* forced unicast rate - do not change STA rate */
return;
}
mode = local->oper_hw_mode;
if (i > mode->num_rates)
i = mode->num_rates;
while (i > 0) {
i--;
if (sta->supp_rates & BIT(i) &&
mode->rates[i].flags & IEEE80211_RATE_SUPPORTED) {
sta->txrate = i;
break;
}
}
}
static struct ieee80211_rate *
rate_control_lowest_rate(struct ieee80211_local *local,
struct ieee80211_hw_mode *mode)
{
int i;
for (i = 0; i < mode->num_rates; i++) {
struct ieee80211_rate *rate = &mode->rates[i];
if (rate->flags & IEEE80211_RATE_SUPPORTED)
return rate;
}
printk(KERN_DEBUG "rate_control_lowest_rate - no supported rates "
"found\n");
return &mode->rates[0];
}
struct global_rate_control {
int dummy;
};
struct sta_rate_control {
unsigned long last_rate_change;
u32 tx_num_failures;
u32 tx_num_xmit;
unsigned long avg_rate_update;
u32 tx_avg_rate_sum;
u32 tx_avg_rate_num;
#ifdef CONFIG_MAC80211_DEBUGFS
struct dentry *tx_avg_rate_sum_dentry;
struct dentry *tx_avg_rate_num_dentry;
#endif
};
static void rate_control_simple_tx_status(void *priv, struct net_device *dev,
struct sk_buff *skb,
struct ieee80211_tx_status *status)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct sta_info *sta;
struct sta_rate_control *srctrl;
sta = sta_info_get(local, hdr->addr1);
if (!sta)
return;
srctrl = sta->rate_ctrl_priv;
srctrl->tx_num_xmit++;
if (status->excessive_retries) {
sta->antenna_sel_tx = sta->antenna_sel_tx == 1 ? 2 : 1;
sta->antenna_sel_rx = sta->antenna_sel_rx == 1 ? 2 : 1;
if (local->sta_antenna_sel == STA_ANTENNA_SEL_SW_CTRL_DEBUG) {
printk(KERN_DEBUG "%s: " MAC_FMT " TX antenna --> %d "
"RX antenna --> %d (@%lu)\n",
dev->name, MAC_ARG(hdr->addr1),
sta->antenna_sel_tx, sta->antenna_sel_rx, jiffies);
}
srctrl->tx_num_failures++;
sta->tx_retry_failed++;
sta->tx_num_consecutive_failures++;
sta->tx_num_mpdu_fail++;
} else {
sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
sta->last_ack_rssi[2] = status->ack_signal;
sta->tx_num_consecutive_failures = 0;
sta->tx_num_mpdu_ok++;
}
sta->tx_retry_count += status->retry_count;
sta->tx_num_mpdu_fail += status->retry_count;
if (time_after(jiffies,
srctrl->last_rate_change + RATE_CONTROL_INTERVAL) &&
srctrl->tx_num_xmit > RATE_CONTROL_MIN_TX) {
u32 per_failed;
srctrl->last_rate_change = jiffies;
per_failed = (100 * sta->tx_num_mpdu_fail) /
(sta->tx_num_mpdu_fail + sta->tx_num_mpdu_ok);
/* TODO: calculate average per_failed to make adjusting
* parameters easier */
#if 0
if (net_ratelimit()) {
printk(KERN_DEBUG "MPDU fail=%d ok=%d per_failed=%d\n",
sta->tx_num_mpdu_fail, sta->tx_num_mpdu_ok,
per_failed);
}
#endif
if (per_failed > local->rate_ctrl_num_down) {
rate_control_rate_dec(local, sta);
} else if (per_failed < local->rate_ctrl_num_up) {
rate_control_rate_inc(local, sta);
}
srctrl->tx_avg_rate_sum += status->control.rate->rate;
srctrl->tx_avg_rate_num++;
srctrl->tx_num_failures = 0;
srctrl->tx_num_xmit = 0;
} else if (sta->tx_num_consecutive_failures >=
RATE_CONTROL_EMERG_DEC) {
rate_control_rate_dec(local, sta);
}
if (srctrl->avg_rate_update + 60 * HZ < jiffies) {
srctrl->avg_rate_update = jiffies;
if (srctrl->tx_avg_rate_num > 0) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
printk(KERN_DEBUG "%s: STA " MAC_FMT " Average rate: "
"%d (%d/%d)\n",
dev->name, MAC_ARG(sta->addr),
srctrl->tx_avg_rate_sum /
srctrl->tx_avg_rate_num,
srctrl->tx_avg_rate_sum,
srctrl->tx_avg_rate_num);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
srctrl->tx_avg_rate_sum = 0;
srctrl->tx_avg_rate_num = 0;
}
}
sta_info_put(sta);
}
static struct ieee80211_rate *
rate_control_simple_get_rate(void *priv, struct net_device *dev,
struct sk_buff *skb,
struct rate_control_extra *extra)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_sub_if_data *sdata;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_hw_mode *mode = extra->mode;
struct sta_info *sta;
int rateidx, nonerp_idx;
u16 fc;
memset(extra, 0, sizeof(*extra));
fc = le16_to_cpu(hdr->frame_control);
if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
(hdr->addr1[0] & 0x01)) {
/* Send management frames and broadcast/multicast data using
* lowest rate. */
/* TODO: this could probably be improved.. */
return rate_control_lowest_rate(local, mode);
}
sta = sta_info_get(local, hdr->addr1);
if (!sta)
return rate_control_lowest_rate(local, mode);
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
sta->txrate = sdata->bss->force_unicast_rateidx;
rateidx = sta->txrate;
if (rateidx >= mode->num_rates)
rateidx = mode->num_rates - 1;
sta->last_txrate = rateidx;
nonerp_idx = rateidx;
while (nonerp_idx > 0 &&
((mode->rates[nonerp_idx].flags & IEEE80211_RATE_ERP) ||
!(mode->rates[nonerp_idx].flags & IEEE80211_RATE_SUPPORTED) ||
!(sta->supp_rates & BIT(nonerp_idx))))
nonerp_idx--;
extra->nonerp = &mode->rates[nonerp_idx];
sta_info_put(sta);
return &mode->rates[rateidx];
}
static void rate_control_simple_rate_init(void *priv, void *priv_sta,
struct ieee80211_local *local,
struct sta_info *sta)
{
struct ieee80211_hw_mode *mode;
int i;
sta->txrate = 0;
mode = local->oper_hw_mode;
/* TODO: This routine should consider using RSSI from previous packets
* as we need to have IEEE 802.1X auth succeed immediately after assoc..
* Until that method is implemented, we will use the lowest supported rate
* as a workaround, */
for (i = 0; i < mode->num_rates; i++) {
if ((sta->supp_rates & BIT(i)) &&
(mode->rates[i].flags & IEEE80211_RATE_SUPPORTED)) {
sta->txrate = i;
break;
}
}
}
static void * rate_control_simple_alloc(struct ieee80211_local *local)
{
struct global_rate_control *rctrl;
rctrl = kzalloc(sizeof(*rctrl), GFP_ATOMIC);
return rctrl;
}
static void rate_control_simple_free(void *priv)
{
struct global_rate_control *rctrl = priv;
kfree(rctrl);
}
static void rate_control_simple_clear(void *priv)
{
}
static void * rate_control_simple_alloc_sta(void *priv, gfp_t gfp)
{
struct sta_rate_control *rctrl;
rctrl = kzalloc(sizeof(*rctrl), gfp);
return rctrl;
}
static void rate_control_simple_free_sta(void *priv, void *priv_sta)
{
struct sta_rate_control *rctrl = priv_sta;
kfree(rctrl);
}
#ifdef CONFIG_MAC80211_DEBUGFS
static int open_file_generic(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static ssize_t sta_tx_avg_rate_sum_read(struct file *file,
char __user *userbuf,
size_t count, loff_t *ppos)
{
struct sta_rate_control *srctrl = file->private_data;
char buf[20];
sprintf(buf, "%d\n", srctrl->tx_avg_rate_sum);
return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
}
static const struct file_operations sta_tx_avg_rate_sum_ops = {
.read = sta_tx_avg_rate_sum_read,
.open = open_file_generic,
};
static ssize_t sta_tx_avg_rate_num_read(struct file *file,
char __user *userbuf,
size_t count, loff_t *ppos)
{
struct sta_rate_control *srctrl = file->private_data;
char buf[20];
sprintf(buf, "%d\n", srctrl->tx_avg_rate_num);
return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
}
static const struct file_operations sta_tx_avg_rate_num_ops = {
.read = sta_tx_avg_rate_num_read,
.open = open_file_generic,
};
static void rate_control_simple_add_sta_debugfs(void *priv, void *priv_sta,
struct dentry *dir)
{
struct sta_rate_control *srctrl = priv_sta;
srctrl->tx_avg_rate_num_dentry =
debugfs_create_file("rc_simple_sta_tx_avg_rate_num", 0400,
dir, srctrl, &sta_tx_avg_rate_num_ops);
srctrl->tx_avg_rate_sum_dentry =
debugfs_create_file("rc_simple_sta_tx_avg_rate_sum", 0400,
dir, srctrl, &sta_tx_avg_rate_sum_ops);
}
static void rate_control_simple_remove_sta_debugfs(void *priv, void *priv_sta)
{
struct sta_rate_control *srctrl = priv_sta;
debugfs_remove(srctrl->tx_avg_rate_sum_dentry);
debugfs_remove(srctrl->tx_avg_rate_num_dentry);
}
#endif
static struct rate_control_ops rate_control_simple = {
.module = THIS_MODULE,
.name = "simple",
.tx_status = rate_control_simple_tx_status,
.get_rate = rate_control_simple_get_rate,
.rate_init = rate_control_simple_rate_init,
.clear = rate_control_simple_clear,
.alloc = rate_control_simple_alloc,
.free = rate_control_simple_free,
.alloc_sta = rate_control_simple_alloc_sta,
.free_sta = rate_control_simple_free_sta,
#ifdef CONFIG_MAC80211_DEBUGFS
.add_sta_debugfs = rate_control_simple_add_sta_debugfs,
.remove_sta_debugfs = rate_control_simple_remove_sta_debugfs,
#endif
};
static int __init rate_control_simple_init(void)
{
return ieee80211_rate_control_register(&rate_control_simple);
}
static void __exit rate_control_simple_exit(void)
{
ieee80211_rate_control_unregister(&rate_control_simple);
}
module_init(rate_control_simple_init);
module_exit(rate_control_simple_exit);
MODULE_DESCRIPTION("Simple rate control algorithm for ieee80211");
MODULE_LICENSE("GPL");
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