/******************************************************************************
*
* Copyright(c) 2005 - 2010 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
*
* The full GNU General Public License is included in this distribution in the
* file called LICENSE.
*
* Contact Information:
* Intel Linux Wireless <ilw@linux.intel.com>
* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
*
*****************************************************************************/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/wireless.h>
#include <net/mac80211.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include "iwl-commands.h"
#include "iwl-3945.h"
#include "iwl-sta.h"
#define RS_NAME "iwl-3945-rs"
static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT_3945] = {
7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
};
static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT_3945] = {
7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
};
static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT_3945] = {
0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
};
static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT_3945] = {
7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
};
struct iwl3945_tpt_entry {
s8 min_rssi;
u8 index;
};
static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
{-60, IWL_RATE_54M_INDEX},
{-64, IWL_RATE_48M_INDEX},
{-72, IWL_RATE_36M_INDEX},
{-80, IWL_RATE_24M_INDEX},
{-84, IWL_RATE_18M_INDEX},
{-85, IWL_RATE_12M_INDEX},
{-87, IWL_RATE_9M_INDEX},
{-89, IWL_RATE_6M_INDEX}
};
static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
{-60, IWL_RATE_54M_INDEX},
{-64, IWL_RATE_48M_INDEX},
{-68, IWL_RATE_36M_INDEX},
{-80, IWL_RATE_24M_INDEX},
{-84, IWL_RATE_18M_INDEX},
{-85, IWL_RATE_12M_INDEX},
{-86, IWL_RATE_11M_INDEX},
{-88, IWL_RATE_5M_INDEX},
{-90, IWL_RATE_2M_INDEX},
{-92, IWL_RATE_1M_INDEX}
};
#define IWL_RATE_MAX_WINDOW 62
#define IWL_RATE_FLUSH (3*HZ)
#define IWL_RATE_WIN_FLUSH (HZ/2)
#define IWL39_RATE_HIGH_TH 11520
#define IWL_SUCCESS_UP_TH 8960
#define IWL_SUCCESS_DOWN_TH 10880
#define IWL_RATE_MIN_FAILURE_TH 6
#define IWL_RATE_MIN_SUCCESS_TH 8
#define IWL_RATE_DECREASE_TH 1920
#define IWL_RATE_RETRY_TH 15
static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
{
u32 index = 0;
u32 table_size = 0;
struct iwl3945_tpt_entry *tpt_table = NULL;
if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
rssi = IWL_MIN_RSSI_VAL;
switch (band) {
case IEEE80211_BAND_2GHZ:
tpt_table = iwl3945_tpt_table_g;
table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
break;
case IEEE80211_BAND_5GHZ:
tpt_table = iwl3945_tpt_table_a;
table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
break;
default:
BUG();
break;
}
while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
index++;
index = min(index, (table_size - 1));
return tpt_table[index].index;
}
static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
{
window->data = 0;
window->success_counter = 0;
window->success_ratio = -1;
window->counter = 0;
window->average_tpt = IWL_INVALID_VALUE;
window->stamp = 0;
}
/**
* iwl3945_rate_scale_flush_windows - flush out the rate scale windows
*
* Returns the number of windows that have gathered data but were
* not flushed. If there were any that were not flushed, then
* reschedule the rate flushing routine.
*/
static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
{
int unflushed = 0;
int i;
unsigned long flags;
struct iwl_priv *priv __maybe_unused = rs_sta->priv;
/*
* For each rate, if we have collected data on that rate
* and it has been more than IWL_RATE_WIN_FLUSH
* since we flushed, clear out the gathered statistics
*/
for (i = 0; i < IWL_RATE_COUNT_3945; i++) {
if (!rs_sta->win[i].counter)
continue;
spin_lock_irqsave(&rs_sta->lock, flags);
if (time_after(jiffies, rs_sta->win[i].stamp +
IWL_RATE_WIN_FLUSH)) {
IWL_DEBUG_RATE(priv, "flushing %d samples of rate "
"index %d\n",
rs_sta->win[i].counter, i);
iwl3945_clear_window(&rs_sta->win[i]);
} else
unflushed++;
spin_unlock_irqrestore(&rs_sta->lock, flags);
}
return unflushed;
}
#define IWL_RATE_FLUSH_MAX 5000 /* msec */
#define IWL_RATE_FLUSH_MIN 50 /* msec */
#define IWL_AVERAGE_PACKETS 1500
static void iwl3945_bg_rate_scale_flush(unsigned long data)
{
struct iwl3945_rs_sta *rs_sta = (void *)data;
struct iwl_priv *priv __maybe_unused = rs_sta->priv;
int unflushed = 0;
unsigned long flags;
u32 packet_count, duration, pps;
IWL_DEBUG_RATE(priv, "enter\n");
unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
spin_lock_irqsave(&rs_sta->lock, flags);
/* Number of packets Rx'd since last time this timer ran */
packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
if (unflushed) {
duration =
jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
IWL_DEBUG_RATE(priv, "Tx'd %d packets in %dms\n",
packet_count, duration);
/* Determine packets per second */
if (duration)
pps = (packet_count * 1000) / duration;
else
pps = 0;
if (pps) {
duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
if (duration < IWL_RATE_FLUSH_MIN)
duration = IWL_RATE_FLUSH_MIN;
else if (duration > IWL_RATE_FLUSH_MAX)
duration = IWL_RATE_FLUSH_MAX;
} else
duration = IWL_RATE_FLUSH_MAX;
rs_sta->flush_time = msecs_to_jiffies(duration);
IWL_DEBUG_RATE(priv, "new flush period: %d msec ave %d\n",
duration, packet_count);
mod_timer(&rs_sta->rate_scale_flush, jiffies +
rs_sta->flush_time);
rs_sta->last_partial_flush = jiffies;
} else {
rs_sta->flush_time = IWL_RATE_FLUSH;
rs_sta->flush_pending = 0;
}
/* If there weren't any unflushed entries, we don't schedule the timer
* to run again */
rs_sta->last_flush = jiffies;
spin_unlock_irqrestore(&rs_sta->lock, flags);
IWL_DEBUG_RATE(priv, "leave\n");
}
/**
* iwl3945_collect_tx_data - Update the success/failure sliding window
*
* We keep a sliding window of the last 64 packets transmitted
* at this rate. window->data contains the bitmask of successful
* packets.
*/
static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
struct iwl3945_rate_scale_data *window,
int success, int retries, int index)
{
unsigned long flags;
s32 fail_count;
struct iwl_priv *priv __maybe_unused = rs_sta->priv;
if (!retries) {
IWL_DEBUG_RATE(priv, "leave: retries == 0 -- should be at least 1\n");
return;
}
spin_lock_irqsave(&rs_sta->lock, flags);
/*
* Keep track of only the latest 62 tx frame attempts in this rate's
* history window; anything older isn't really relevant any more.
* If we have filled up the sliding window, drop the oldest attempt;
* if the oldest attempt (highest bit in bitmap) shows "success",
* subtract "1" from the success counter (this is the main reason
* we keep these bitmaps!).
* */
while (retries > 0) {
if (window->counter >= IWL_RATE_MAX_WINDOW) {
/* remove earliest */
window->counter = IWL_RATE_MAX_WINDOW - 1;
if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1))) {
window->data &= ~(1ULL << (IWL_RATE_MAX_WINDOW - 1));
window->success_counter--;
}
}
/* Increment frames-attempted counter */
window->counter++;
/* Shift bitmap by one frame (throw away oldest history),
* OR in "1", and increment "success" if this
* frame was successful. */
window->data <<= 1;
if (success > 0) {
window->success_counter++;
window->data |= 0x1;
success--;
}
retries--;
}
/* Calculate current success ratio, avoid divide-by-0! */
if (window->counter > 0)
window->success_ratio = 128 * (100 * window->success_counter)
/ window->counter;
else
window->success_ratio = IWL_INVALID_VALUE;
fail_count = window->counter - window->success_counter;
/* Calculate average throughput, if we have enough history. */
if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
(window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
window->average_tpt = ((window->success_ratio *
rs_sta->expected_tpt[index] + 64) / 128);
else
window->average_tpt = IWL_INVALID_VALUE;
/* Tag this window as having been updated */
window->stamp = jiffies;
spin_unlock_irqrestore(&rs_sta->lock, flags);
}
static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
struct ieee80211_sta *sta, void *priv_sta)
{
struct iwl3945_rs_sta *rs_sta = priv_sta;
struct iwl_priv *priv = (struct iwl_priv *)priv_r;
int i;
IWL_DEBUG_RATE(priv, "enter\n");
spin_lock_init(&rs_sta->lock);
rs_sta->priv = priv;
rs_sta->start_rate = IWL_RATE_INVALID;
/* default to just 802.11b */
rs_sta->expected_tpt = iwl3945_expected_tpt_b;
rs_sta->last_partial_flush = jiffies;
rs_sta->last_flush = jiffies;
rs_sta->flush_time = IWL_RATE_FLUSH;
rs_sta->last_tx_packets = 0;
rs_sta->ibss_sta_added = 0;
init_timer(&rs_sta->rate_scale_flush);
rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
rs_sta->rate_scale_flush.function = iwl3945_bg_rate_scale_flush;
for (i = 0; i < IWL_RATE_COUNT_3945; i++)
iwl3945_clear_window(&rs_sta->win[i]);
/* TODO: what is a good starting rate for STA? About middle? Maybe not
* the lowest or the highest rate.. Could consider using RSSI from
* previous packets? Need to have IEEE 802.1X auth succeed immediately
* after assoc.. */
for (i = sband->n_bitrates - 1; i >= 0; i--) {
if (sta->supp_rates[sband->band] & (1 << i)) {
rs_sta->last_txrate_idx = i;
break;
}
}
priv->sta_supp_rates = sta->supp_rates[sband->band];
/* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
if (sband->band == IEEE80211_BAND_5GHZ) {
rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
priv->sta_supp_rates = priv->sta_supp_rates <<
IWL_FIRST_OFDM_RATE;
}
IWL_DEBUG_RATE(priv, "leave\n");
}
static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
{
return hw->priv;
}
/* rate scale requires free function to be implemented */
static void rs_free(void *priv)
{
return;
}
static void *rs_alloc_sta(void *iwl_priv, struct ieee80211_sta *sta, gfp_t gfp)
{
struct iwl3945_rs_sta *rs_sta;
struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
struct iwl_priv *priv __maybe_unused = iwl_priv;
IWL_DEBUG_RATE(priv, "enter\n");
rs_sta = &psta->rs_sta;
IWL_DEBUG_RATE(priv, "leave\n");
return rs_sta;
}
static void rs_free_sta(void *iwl_priv, struct ieee80211_sta *sta,
void *priv_sta)
{
struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
struct iwl3945_rs_sta *rs_sta = &psta->rs_sta;
struct iwl_priv *priv __maybe_unused = rs_sta->priv;
IWL_DEBUG_RATE(priv, "enter\n");
del_timer_sync(&rs_sta->rate_scale_flush);
IWL_DEBUG_RATE(priv, "leave\n");
}
/**
* rs_tx_status - Update rate control values based on Tx results
*
* NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
* the hardware for each rate.
*/
static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
struct ieee80211_sta *sta, void *priv_sta,
struct sk_buff *skb)
{
s8 retries = 0, current_count;
int scale_rate_index, first_index, last_index;
unsigned long flags;
struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
struct iwl3945_rs_sta *rs_sta = priv_sta;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
IWL_DEBUG_RATE(priv, "enter\n");
retries = info->status.rates[0].count;
/* Sanity Check for retries */
if (retries > IWL_RATE_RETRY_TH)
retries = IWL_RATE_RETRY_TH;
first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
if ((first_index < 0) || (first_index >= IWL_RATE_COUNT_3945)) {
IWL_DEBUG_RATE(priv, "leave: Rate out of bounds: %d\n", first_index);
return;
}
if (!priv_sta) {
IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n");
return;
}
rs_sta->tx_packets++;
scale_rate_index = first_index;
last_index = first_index;
/*
* Update the window for each rate. We determine which rates
* were Tx'd based on the total number of retries vs. the number
* of retries configured for each rate -- currently set to the
* priv value 'retry_rate' vs. rate specific
*
* On exit from this while loop last_index indicates the rate
* at which the frame was finally transmitted (or failed if no
* ACK)
*/
while (retries > 1) {
if ((retries - 1) < priv->retry_rate) {
current_count = (retries - 1);
last_index = scale_rate_index;
} else {
current_count = priv->retry_rate;
last_index = iwl3945_rs_next_rate(priv,
scale_rate_index);
}
/* Update this rate accounting for as many retries
* as was used for it (per current_count) */
iwl3945_collect_tx_data(rs_sta,
&rs_sta->win[scale_rate_index],
0, current_count, scale_rate_index);
IWL_DEBUG_RATE(priv, "Update rate %d for %d retries.\n",
scale_rate_index, current_count);
retries -= current_count;
scale_rate_index = last_index;
}
/* Update the last index window with success/failure based on ACK */
IWL_DEBUG_RATE(priv, "Update rate %d with %s.\n",
last_index,
(info->flags & IEEE80211_TX_STAT_ACK) ?
"success" : "failure");
iwl3945_collect_tx_data(rs_sta,
&rs_sta->win[last_index],
info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
/* We updated the rate scale window -- if its been more than
* flush_time since the last run, schedule the flush
* again */
spin_lock_irqsave(&rs_sta->lock, flags);
if (!rs_sta->flush_pending &&
time_after(jiffies, rs_sta->last_flush +
rs_sta->flush_time)) {
rs_sta->last_partial_flush = jiffies;
rs_sta->flush_pending = 1;
mod_timer(&rs_sta->rate_scale_flush,
jiffies + rs_sta->flush_time);
}
spin_unlock_irqrestore(&rs_sta->lock, flags);
IWL_DEBUG_RATE(priv, "leave\n");
return;
}
static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
u8 index, u16 rate_mask, enum ieee80211_band band)
{
u8 high = IWL_RATE_INVALID;
u8 low = IWL_RATE_INVALID;
struct iwl_priv *priv __maybe_unused = rs_sta->priv;
/* 802.11A walks to the next literal adjacent rate in
* the rate table */
if (unlikely(band == IEEE80211_BAND_5GHZ)) {
int i;
u32 mask;
/* Find the previous rate that is in the rate mask */
i = index - 1;
for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
if (rate_mask & mask) {
low = i;
break;
}
}
/* Find the next rate that is in the rate mask */
i = index + 1;
for (mask = (1 << i); i < IWL_RATE_COUNT_3945;
i++, mask <<= 1) {
if (rate_mask & mask) {
high = i;
break;
}
}
return (high << 8) | low;
}
low = index;
while (low != IWL_RATE_INVALID) {
if (rs_sta->tgg)
low = iwl3945_rates[low].prev_rs_tgg;
else
low = iwl3945_rates[low].prev_rs;
if (low == IWL_RATE_INVALID)
break;
if (rate_mask & (1 << low))
break;
IWL_DEBUG_RATE(priv, "Skipping masked lower rate: %d\n", low);
}
high = index;
while (high != IWL_RATE_INVALID) {
if (rs_sta->tgg)
high = iwl3945_rates[high].next_rs_tgg;
else
high = iwl3945_rates[high].next_rs;
if (high == IWL_RATE_INVALID)
break;
if (rate_mask & (1 << high))
break;
IWL_DEBUG_RATE(priv, "Skipping masked higher rate: %d\n", high);
}
return (high << 8) | low;
}
/**
* rs_get_rate - find the rate for the requested packet
*
* Returns the ieee80211_rate structure allocated by the driver.
*
* The rate control algorithm has no internal mapping between hw_mode's
* rate ordering and the rate ordering used by the rate control algorithm.
*
* The rate control algorithm uses a single table of rates that goes across
* the entire A/B/G spectrum vs. being limited to just one particular
* hw_mode.
*
* As such, we can't convert the index obtained below into the hw_mode's
* rate table and must reference the driver allocated rate table
*
*/
static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
void *priv_sta, struct ieee80211_tx_rate_control *txrc)
{
struct ieee80211_supported_band *sband = txrc->sband;
struct sk_buff *skb = txrc->skb;
u8 low = IWL_RATE_INVALID;
u8 high = IWL_RATE_INVALID;
u16 high_low;
int index;
struct iwl3945_rs_sta *rs_sta = priv_sta;
struct iwl3945_rate_scale_data *window = NULL;
int current_tpt = IWL_INVALID_VALUE;
int low_tpt = IWL_INVALID_VALUE;
int high_tpt = IWL_INVALID_VALUE;
u32 fail_count;
s8 scale_action = 0;
unsigned long flags;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
u16 rate_mask = sta ? sta->supp_rates[sband->band] : 0;
s8 max_rate_idx = -1;
struct iwl_priv *priv = (struct iwl_priv *)priv_r;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
IWL_DEBUG_RATE(priv, "enter\n");
if (rate_control_send_low(sta, priv_sta, txrc))
return;
rate_mask = sta->supp_rates[sband->band];
/* get user max rate if set */
max_rate_idx = txrc->max_rate_idx;
if ((sband->band == IEEE80211_BAND_5GHZ) && (max_rate_idx != -1))
max_rate_idx += IWL_FIRST_OFDM_RATE;
if ((max_rate_idx < 0) || (max_rate_idx >= IWL_RATE_COUNT))
max_rate_idx = -1;
index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT_3945 - 1);
if (sband->band == IEEE80211_BAND_5GHZ)
rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
!rs_sta->ibss_sta_added) {
u8 sta_id = iwl_find_station(priv, hdr->addr1);
if (sta_id == IWL_INVALID_STATION) {
IWL_DEBUG_RATE(priv, "LQ: ADD station %pM\n",
hdr->addr1);
sta_id = iwl_add_station(priv, hdr->addr1, false,
CMD_ASYNC, NULL);
}
if (sta_id != IWL_INVALID_STATION)
rs_sta->ibss_sta_added = 1;
}
spin_lock_irqsave(&rs_sta->lock, flags);
/* for recent assoc, choose best rate regarding
* to rssi value
*/
if (rs_sta->start_rate != IWL_RATE_INVALID) {
if (rs_sta->start_rate < index &&
(rate_mask & (1 << rs_sta->start_rate)))
index = rs_sta->start_rate;
rs_sta->start_rate = IWL_RATE_INVALID;
}
/* force user max rate if set by user */
if ((max_rate_idx != -1) && (max_rate_idx < index)) {
if (rate_mask & (1 << max_rate_idx))
index = max_rate_idx;
}
window = &(rs_sta->win[index]);
fail_count = window->counter - window->success_counter;
if (((fail_count < IWL_RATE_MIN_FAILURE_TH) &&
(window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
spin_unlock_irqrestore(&rs_sta->lock, flags);
IWL_DEBUG_RATE(priv, "Invalid average_tpt on rate %d: "
"counter: %d, success_counter: %d, "
"expected_tpt is %sNULL\n",
index,
window->counter,
window->success_counter,
rs_sta->expected_tpt ? "not " : "");
/* Can't calculate this yet; not enough history */
window->average_tpt = IWL_INVALID_VALUE;
goto out;
}
current_tpt = window->average_tpt;
high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
sband->band);
low = high_low & 0xff;
high = (high_low >> 8) & 0xff;
/* If user set max rate, dont allow higher than user constrain */
if ((max_rate_idx != -1) && (max_rate_idx < high))
high = IWL_RATE_INVALID;
/* Collect Measured throughputs of adjacent rates */
if (low != IWL_RATE_INVALID)
low_tpt = rs_sta->win[low].average_tpt;
if (high != IWL_RATE_INVALID)
high_tpt = rs_sta->win[high].average_tpt;
spin_unlock_irqrestore(&rs_sta->lock, flags);
scale_action = 0;
/* Low success ratio , need to drop the rate */
if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
IWL_DEBUG_RATE(priv, "decrease rate because of low success_ratio\n");
scale_action = -1;
/* No throughput measured yet for adjacent rates,
* try increase */
} else if ((low_tpt == IWL_INVALID_VALUE) &&
(high_tpt == IWL_INVALID_VALUE)) {
if (high != IWL_RATE_INVALID && window->success_ratio >= IWL_RATE_INCREASE_TH)
scale_action = 1;
else if (low != IWL_RATE_INVALID)
scale_action = 0;
/* Both adjacent throughputs are measured, but neither one has
* better throughput; we're using the best rate, don't change
* it! */
} else if ((low_tpt != IWL_INVALID_VALUE) &&
(high_tpt != IWL_INVALID_VALUE) &&
(low_tpt < current_tpt) && (high_tpt < current_tpt)) {
IWL_DEBUG_RATE(priv, "No action -- low [%d] & high [%d] < "
"current_tpt [%d]\n",
low_tpt, high_tpt, current_tpt);
scale_action = 0;
/* At least one of the rates has better throughput */
} else {
if (high_tpt != IWL_INVALID_VALUE) {
/* High rate has better throughput, Increase
* rate */
if (high_tpt > current_tpt &&
window->success_ratio >= IWL_RATE_INCREASE_TH)
scale_action = 1;
else {
IWL_DEBUG_RATE(priv,
"decrease rate because of high tpt\n");
scale_action = 0;
}
} else if (low_tpt != IWL_INVALID_VALUE) {
if (low_tpt > current_tpt) {
IWL_DEBUG_RATE(priv,
"decrease rate because of low tpt\n");
scale_action = -1;
} else if (window->success_ratio >= IWL_RATE_INCREASE_TH) {
/* Lower rate has better
* throughput,decrease rate */
scale_action = 1;
}
}
}
/* Sanity check; asked for decrease, but success rate or throughput
* has been good at old rate. Don't change it. */
if ((scale_action == -1) && (low != IWL_RATE_INVALID) &&
((window->success_ratio > IWL_RATE_HIGH_TH) ||
(current_tpt > (100 * rs_sta->expected_tpt[low]))))
scale_action = 0;
switch (scale_action) {
case -1:
/* Decrese rate */
if (low != IWL_RATE_INVALID)
index = low;
break;
case 1:
/* Increase rate */
if (high != IWL_RATE_INVALID)
index = high;
break;
case 0:
default:
/* No change */
break;
}
IWL_DEBUG_RATE(priv, "Selected %d (action %d) - low %d high %d\n",
index, scale_action, low, high);
out:
rs_sta->last_txrate_idx = index;
if (sband->band == IEEE80211_BAND_5GHZ)
info->control.rates[0].idx = rs_sta->last_txrate_idx -
IWL_FIRST_OFDM_RATE;
else
info->control.rates[0].idx = rs_sta->last_txrate_idx;
IWL_DEBUG_RATE(priv, "leave: %d\n", index);
}
#ifdef CONFIG_MAC80211_DEBUGFS
static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
char __user *user_buf,
size_t count, loff_t *ppos)
{
char *buff;
int desc = 0;
int j;
ssize_t ret;
struct iwl3945_rs_sta *lq_sta = file->private_data;
buff = kmalloc(1024, GFP_KERNEL);
if (!buff)
return -ENOMEM;
desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
"rate=0x%X flush time %d\n",
lq_sta->tx_packets,
lq_sta->last_txrate_idx,
lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
for (j = 0; j < IWL_RATE_COUNT_3945; j++) {
desc += sprintf(buff+desc,
"counter=%d success=%d %%=%d\n",
lq_sta->win[j].counter,
lq_sta->win[j].success_counter,
lq_sta->win[j].success_ratio);
}
ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
kfree(buff);
return ret;
}
static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
.read = iwl3945_sta_dbgfs_stats_table_read,
.open = iwl3945_open_file_generic,
};
static void iwl3945_add_debugfs(void *priv, void *priv_sta,
struct dentry *dir)
{
struct iwl3945_rs_sta *lq_sta = priv_sta;
lq_sta->rs_sta_dbgfs_stats_table_file =
debugfs_create_file("rate_stats_table", 0600, dir,
lq_sta, &rs_sta_dbgfs_stats_table_ops);
}
static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
{
struct iwl3945_rs_sta *lq_sta = priv_sta;
debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
}
#endif
static struct rate_control_ops rs_ops = {
.module = NULL,
.name = RS_NAME,
.tx_status = rs_tx_status,
.get_rate = rs_get_rate,
.rate_init = rs_rate_init,
.alloc = rs_alloc,
.free = rs_free,
.alloc_sta = rs_alloc_sta,
.free_sta = rs_free_sta,
#ifdef CONFIG_MAC80211_DEBUGFS
.add_sta_debugfs = iwl3945_add_debugfs,
.remove_sta_debugfs = iwl3945_remove_debugfs,
#endif
};
void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
{
struct iwl_priv *priv = hw->priv;
s32 rssi = 0;
unsigned long flags;
struct iwl3945_rs_sta *rs_sta;
struct ieee80211_sta *sta;
struct iwl3945_sta_priv *psta;
IWL_DEBUG_RATE(priv, "enter\n");
rcu_read_lock();
sta = ieee80211_find_sta(priv->vif,
priv->stations[sta_id].sta.sta.addr);
if (!sta) {
rcu_read_unlock();
return;
}
psta = (void *) sta->drv_priv;
rs_sta = &psta->rs_sta;
spin_lock_irqsave(&rs_sta->lock, flags);
rs_sta->tgg = 0;
switch (priv->band) {
case IEEE80211_BAND_2GHZ:
/* TODO: this always does G, not a regression */
if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
rs_sta->tgg = 1;
rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
} else
rs_sta->expected_tpt = iwl3945_expected_tpt_g;
break;
case IEEE80211_BAND_5GHZ:
rs_sta->expected_tpt = iwl3945_expected_tpt_a;
break;
case IEEE80211_NUM_BANDS:
BUG();
break;
}
spin_unlock_irqrestore(&rs_sta->lock, flags);
rssi = priv->last_rx_rssi;
if (rssi == 0)
rssi = IWL_MIN_RSSI_VAL;
IWL_DEBUG_RATE(priv, "Network RSSI: %d\n", rssi);
rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
IWL_DEBUG_RATE(priv, "leave: rssi %d assign rate index: "
"%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
iwl3945_rates[rs_sta->start_rate].plcp);
rcu_read_unlock();
}
int iwl3945_rate_control_register(void)
{
return ieee80211_rate_control_register(&rs_ops);
}
void iwl3945_rate_control_unregister(void)
{
ieee80211_rate_control_unregister(&rs_ops);
}
