linux/drivers/net/wireless/rt2x00/rt2x00config.c
Ivo van Doorn 0262ab0df6 rt2x00: Fix race conditions in flag handling
Some of the flags should be accessed atomically to
prevent race conditions. The flags that are most important
are those that can change often and indicate the actual
state of the device, queue or queue entry.

The big flag rename was done to move all state flags to
the same naming type as the other rt2x00dev flags and
made sure all places where the flags were used were changed. ;)

Thanks to Stephen for most of the queue flags updates,
which fixes some of the most obvious consequences of the
race conditions. Among those the notorious:

rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the non-full queue 0.
rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the non-full queue 0.
rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the non-full queue 0.

Signed-off-by: Stephen Blackheath <tramp.enshrine.stephen@blacksapphire.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-29 16:24:11 -04:00

312 lines
8.9 KiB
C

/*
Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
<http://rt2x00.serialmonkey.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/*
Module: rt2x00lib
Abstract: rt2x00 generic configuration routines.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include "rt2x00.h"
#include "rt2x00lib.h"
void rt2x00lib_config_intf(struct rt2x00_dev *rt2x00dev,
struct rt2x00_intf *intf,
enum ieee80211_if_types type,
u8 *mac, u8 *bssid)
{
struct rt2x00intf_conf conf;
unsigned int flags = 0;
conf.type = type;
switch (type) {
case IEEE80211_IF_TYPE_IBSS:
case IEEE80211_IF_TYPE_AP:
conf.sync = TSF_SYNC_BEACON;
break;
case IEEE80211_IF_TYPE_STA:
conf.sync = TSF_SYNC_INFRA;
break;
default:
conf.sync = TSF_SYNC_NONE;
break;
}
/*
* Note that when NULL is passed as address we will send
* 00:00:00:00:00 to the device to clear the address.
* This will prevent the device being confused when it wants
* to ACK frames or consideres itself associated.
*/
memset(&conf.mac, 0, sizeof(conf.mac));
if (mac)
memcpy(&conf.mac, mac, ETH_ALEN);
memset(&conf.bssid, 0, sizeof(conf.bssid));
if (bssid)
memcpy(&conf.bssid, bssid, ETH_ALEN);
flags |= CONFIG_UPDATE_TYPE;
if (mac || (!rt2x00dev->intf_ap_count && !rt2x00dev->intf_sta_count))
flags |= CONFIG_UPDATE_MAC;
if (bssid || (!rt2x00dev->intf_ap_count && !rt2x00dev->intf_sta_count))
flags |= CONFIG_UPDATE_BSSID;
rt2x00dev->ops->lib->config_intf(rt2x00dev, intf, &conf, flags);
}
void rt2x00lib_config_erp(struct rt2x00_dev *rt2x00dev,
struct rt2x00_intf *intf,
struct ieee80211_bss_conf *bss_conf)
{
struct rt2x00lib_erp erp;
memset(&erp, 0, sizeof(erp));
erp.short_preamble = bss_conf->use_short_preamble;
erp.cts_protection = bss_conf->use_cts_prot;
erp.ack_timeout = PLCP + get_duration(ACK_SIZE, 10);
erp.ack_consume_time = SIFS + PLCP + get_duration(ACK_SIZE, 10);
if (rt2x00dev->hw->conf.flags & IEEE80211_CONF_SHORT_SLOT_TIME)
erp.ack_timeout += SHORT_DIFS;
else
erp.ack_timeout += DIFS;
if (bss_conf->use_short_preamble) {
erp.ack_timeout += SHORT_PREAMBLE;
erp.ack_consume_time += SHORT_PREAMBLE;
} else {
erp.ack_timeout += PREAMBLE;
erp.ack_consume_time += PREAMBLE;
}
rt2x00dev->ops->lib->config_erp(rt2x00dev, &erp);
}
void rt2x00lib_config_antenna(struct rt2x00_dev *rt2x00dev,
enum antenna rx, enum antenna tx)
{
struct rt2x00lib_conf libconf;
libconf.ant.rx = rx;
libconf.ant.tx = tx;
if (rx == rt2x00dev->link.ant.active.rx &&
tx == rt2x00dev->link.ant.active.tx)
return;
/*
* Antenna setup changes require the RX to be disabled,
* else the changes will be ignored by the device.
*/
if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_OFF_LINK);
/*
* Write new antenna setup to device and reset the link tuner.
* The latter is required since we need to recalibrate the
* noise-sensitivity ratio for the new setup.
*/
rt2x00dev->ops->lib->config(rt2x00dev, &libconf, CONFIG_UPDATE_ANTENNA);
rt2x00lib_reset_link_tuner(rt2x00dev);
rt2x00_reset_link_ant_rssi(&rt2x00dev->link);
rt2x00dev->link.ant.active.rx = libconf.ant.rx;
rt2x00dev->link.ant.active.tx = libconf.ant.tx;
if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON_LINK);
}
static u32 rt2x00lib_get_basic_rates(struct ieee80211_supported_band *band)
{
const struct rt2x00_rate *rate;
unsigned int i;
u32 mask = 0;
for (i = 0; i < band->n_bitrates; i++) {
rate = rt2x00_get_rate(band->bitrates[i].hw_value);
if (rate->flags & DEV_RATE_BASIC)
mask |= rate->ratemask;
}
return mask;
}
void rt2x00lib_config(struct rt2x00_dev *rt2x00dev,
struct ieee80211_conf *conf, const int force_config)
{
struct rt2x00lib_conf libconf;
struct ieee80211_supported_band *band;
struct antenna_setup *default_ant = &rt2x00dev->default_ant;
struct antenna_setup *active_ant = &rt2x00dev->link.ant.active;
int flags = 0;
int short_slot_time;
/*
* In some situations we want to force all configurations
* to be reloaded (When resuming for instance).
*/
if (force_config) {
flags = CONFIG_UPDATE_ALL;
goto config;
}
/*
* Check which configuration options have been
* updated and should be send to the device.
*/
if (rt2x00dev->rx_status.band != conf->channel->band)
flags |= CONFIG_UPDATE_PHYMODE;
if (rt2x00dev->rx_status.freq != conf->channel->center_freq)
flags |= CONFIG_UPDATE_CHANNEL;
if (rt2x00dev->tx_power != conf->power_level)
flags |= CONFIG_UPDATE_TXPOWER;
/*
* Determining changes in the antenna setups request several checks:
* antenna_sel_{r,t}x = 0
* -> Does active_{r,t}x match default_{r,t}x
* -> Is default_{r,t}x SW_DIVERSITY
* antenna_sel_{r,t}x = 1/2
* -> Does active_{r,t}x match antenna_sel_{r,t}x
* The reason for not updating the antenna while SW diversity
* should be used is simple: Software diversity means that
* we should switch between the antenna's based on the
* quality. This means that the current antenna is good enough
* to work with untill the link tuner decides that an antenna
* switch should be performed.
*/
if (!conf->antenna_sel_rx &&
default_ant->rx != ANTENNA_SW_DIVERSITY &&
default_ant->rx != active_ant->rx)
flags |= CONFIG_UPDATE_ANTENNA;
else if (conf->antenna_sel_rx &&
conf->antenna_sel_rx != active_ant->rx)
flags |= CONFIG_UPDATE_ANTENNA;
else if (active_ant->rx == ANTENNA_SW_DIVERSITY)
flags |= CONFIG_UPDATE_ANTENNA;
if (!conf->antenna_sel_tx &&
default_ant->tx != ANTENNA_SW_DIVERSITY &&
default_ant->tx != active_ant->tx)
flags |= CONFIG_UPDATE_ANTENNA;
else if (conf->antenna_sel_tx &&
conf->antenna_sel_tx != active_ant->tx)
flags |= CONFIG_UPDATE_ANTENNA;
else if (active_ant->tx == ANTENNA_SW_DIVERSITY)
flags |= CONFIG_UPDATE_ANTENNA;
/*
* The following configuration options are never
* stored anywhere and will always be updated.
*/
flags |= CONFIG_UPDATE_SLOT_TIME;
flags |= CONFIG_UPDATE_BEACON_INT;
/*
* We have determined what options should be updated,
* now precalculate device configuration values depending
* on what configuration options need to be updated.
*/
config:
memset(&libconf, 0, sizeof(libconf));
if (flags & CONFIG_UPDATE_PHYMODE) {
band = &rt2x00dev->bands[conf->channel->band];
libconf.band = conf->channel->band;
libconf.basic_rates = rt2x00lib_get_basic_rates(band);
}
if (flags & CONFIG_UPDATE_CHANNEL) {
memcpy(&libconf.rf,
&rt2x00dev->spec.channels[conf->channel->hw_value],
sizeof(libconf.rf));
memcpy(&libconf.channel,
&rt2x00dev->spec.channels_info[conf->channel->hw_value],
sizeof(libconf.channel));
}
if (flags & CONFIG_UPDATE_ANTENNA) {
if (conf->antenna_sel_rx)
libconf.ant.rx = conf->antenna_sel_rx;
else if (default_ant->rx != ANTENNA_SW_DIVERSITY)
libconf.ant.rx = default_ant->rx;
else if (active_ant->rx == ANTENNA_SW_DIVERSITY)
libconf.ant.rx = ANTENNA_B;
else
libconf.ant.rx = active_ant->rx;
if (conf->antenna_sel_tx)
libconf.ant.tx = conf->antenna_sel_tx;
else if (default_ant->tx != ANTENNA_SW_DIVERSITY)
libconf.ant.tx = default_ant->tx;
else if (active_ant->tx == ANTENNA_SW_DIVERSITY)
libconf.ant.tx = ANTENNA_B;
else
libconf.ant.tx = active_ant->tx;
}
if (flags & CONFIG_UPDATE_SLOT_TIME) {
short_slot_time = conf->flags & IEEE80211_CONF_SHORT_SLOT_TIME;
libconf.slot_time =
short_slot_time ? SHORT_SLOT_TIME : SLOT_TIME;
libconf.sifs = SIFS;
libconf.pifs = short_slot_time ? SHORT_PIFS : PIFS;
libconf.difs = short_slot_time ? SHORT_DIFS : DIFS;
libconf.eifs = short_slot_time ? SHORT_EIFS : EIFS;
}
libconf.conf = conf;
/*
* Start configuration.
*/
rt2x00dev->ops->lib->config(rt2x00dev, &libconf, flags);
/*
* Some configuration changes affect the link quality
* which means we need to reset the link tuner.
*/
if (flags & (CONFIG_UPDATE_CHANNEL | CONFIG_UPDATE_ANTENNA))
rt2x00lib_reset_link_tuner(rt2x00dev);
if (flags & CONFIG_UPDATE_PHYMODE) {
rt2x00dev->curr_band = conf->channel->band;
rt2x00dev->rx_status.band = conf->channel->band;
}
rt2x00dev->rx_status.freq = conf->channel->center_freq;
rt2x00dev->tx_power = conf->power_level;
if (flags & CONFIG_UPDATE_ANTENNA) {
rt2x00dev->link.ant.active.rx = libconf.ant.rx;
rt2x00dev->link.ant.active.tx = libconf.ant.tx;
}
}