path: root/drivers/net/wireless/iwlegacy/3945-rs.c

/******************************************************************************
 *
 * Copyright(c) 2005 - 2011 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/slab.h>
#include <net/mac80211.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/delay.h>

#include <linux/workqueue.h>

#include "commands.h"
#include "3945.h"

#define RS_NAME "iwl-3945-rs"

static s32 il3945_expected_tpt_g[RATE_COUNT_3945] = {
	7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
};

static s32 il3945_expected_tpt_g_prot[RATE_COUNT_3945] = {
	7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
};

static s32 il3945_expected_tpt_a[RATE_COUNT_3945] = {
	0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
};

static s32 il3945_expected_tpt_b[RATE_COUNT_3945] = {
	7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
};

struct il3945_tpt_entry {
	s8 min_rssi;
	u8 idx;
};

static struct il3945_tpt_entry il3945_tpt_table_a[] = {
	{-60, RATE_54M_IDX},
	{-64, RATE_48M_IDX},
	{-72, RATE_36M_IDX},
	{-80, RATE_24M_IDX},
	{-84, RATE_18M_IDX},
	{-85, RATE_12M_IDX},
	{-87, RATE_9M_IDX},
	{-89, RATE_6M_IDX}
};

static struct il3945_tpt_entry il3945_tpt_table_g[] = {
	{-60, RATE_54M_IDX},
	{-64, RATE_48M_IDX},
	{-68, RATE_36M_IDX},
	{-80, RATE_24M_IDX},
	{-84, RATE_18M_IDX},
	{-85, RATE_12M_IDX},
	{-86, RATE_11M_IDX},
	{-88, RATE_5M_IDX},
	{-90, RATE_2M_IDX},
	{-92, RATE_1M_IDX}
};

#define RATE_MAX_WINDOW		62
#define RATE_FLUSH		(3*HZ)
#define RATE_WIN_FLUSH		(HZ/2)
#define IL39_RATE_HIGH_TH	11520
#define IL_SUCCESS_UP_TH	8960
#define IL_SUCCESS_DOWN_TH	10880
#define RATE_MIN_FAILURE_TH	6
#define RATE_MIN_SUCCESS_TH	8
#define RATE_DECREASE_TH	1920
#define RATE_RETRY_TH		15

static u8
il3945_get_rate_idx_by_rssi(s32 rssi, enum ieee80211_band band)
{
	u32 idx = 0;
	u32 table_size = 0;
	struct il3945_tpt_entry *tpt_table = NULL;

	if (rssi < IL_MIN_RSSI_VAL || rssi > IL_MAX_RSSI_VAL)
		rssi = IL_MIN_RSSI_VAL;

	switch (band) {
	case IEEE80211_BAND_2GHZ:
		tpt_table = il3945_tpt_table_g;
		table_size = ARRAY_SIZE(il3945_tpt_table_g);
		break;
	case IEEE80211_BAND_5GHZ:
		tpt_table = il3945_tpt_table_a;
		table_size = ARRAY_SIZE(il3945_tpt_table_a);
		break;
	default:
		BUG();
		break;
	}

	while (idx < table_size && rssi < tpt_table[idx].min_rssi)
		idx++;

	idx = min(idx, table_size - 1);

	return tpt_table[idx].idx;
}

static void
il3945_clear_win(struct il3945_rate_scale_data *win)
{
	win->data = 0;
	win->success_counter = 0;
	win->success_ratio = -1;
	win->counter = 0;
	win->average_tpt = IL_INVALID_VALUE;
	win->stamp = 0;
}

/**
 * il3945_rate_scale_flush_wins - flush out the rate scale wins
 *
 * Returns the number of wins that have gathered data but were
 * not flushed.  If there were any that were not flushed, then
 * reschedule the rate flushing routine.
 */
static int
il3945_rate_scale_flush_wins(struct il3945_rs_sta *rs_sta)
{
	int unflushed = 0;
	int i;
	unsigned long flags;
	struct il_priv *il __maybe_unused = rs_sta->il;

	/*
	 * For each rate, if we have collected data on that rate
	 * and it has been more than RATE_WIN_FLUSH
	 * since we flushed, clear out the gathered stats
	 */
	for (i = 0; i < 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 + RATE_WIN_FLUSH)) {
			D_RATE("flushing %d samples of rate " "idx %d\n",
			       rs_sta->win[i].counter, i);