// SPDX-License-Identifier: GPL-2.0-or-later
|
/*
|
Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
|
<http://rt2x00.serialmonkey.com>
|
|
*/
|
|
/*
|
Module: rt2x00lib
|
Abstract: rt2x00 generic link tuning routines.
|
*/
|
|
#include <linux/kernel.h>
|
#include <linux/module.h>
|
|
#include "rt2x00.h"
|
#include "rt2x00lib.h"
|
|
/*
|
* When we lack RSSI information return something less then -80 to
|
* tell the driver to tune the device to maximum sensitivity.
|
*/
|
#define DEFAULT_RSSI -128
|
|
static inline int rt2x00link_get_avg_rssi(struct ewma_rssi *ewma)
|
{
|
unsigned long avg;
|
|
avg = ewma_rssi_read(ewma);
|
if (avg)
|
return -avg;
|
|
return DEFAULT_RSSI;
|
}
|
|
static int rt2x00link_antenna_get_link_rssi(struct rt2x00_dev *rt2x00dev)
|
{
|
struct link_ant *ant = &rt2x00dev->link.ant;
|
|
if (rt2x00dev->link.qual.rx_success)
|
return rt2x00link_get_avg_rssi(&ant->rssi_ant);
|
|
return DEFAULT_RSSI;
|
}
|
|
static int rt2x00link_antenna_get_rssi_history(struct rt2x00_dev *rt2x00dev)
|
{
|
struct link_ant *ant = &rt2x00dev->link.ant;
|
|
if (ant->rssi_history)
|
return ant->rssi_history;
|
return DEFAULT_RSSI;
|
}
|
|
static void rt2x00link_antenna_update_rssi_history(struct rt2x00_dev *rt2x00dev,
|
int rssi)
|
{
|
struct link_ant *ant = &rt2x00dev->link.ant;
|
ant->rssi_history = rssi;
|
}
|
|
static void rt2x00link_antenna_reset(struct rt2x00_dev *rt2x00dev)
|
{
|
ewma_rssi_init(&rt2x00dev->link.ant.rssi_ant);
|
}
|
|
static void rt2x00lib_antenna_diversity_sample(struct rt2x00_dev *rt2x00dev)
|
{
|
struct link_ant *ant = &rt2x00dev->link.ant;
|
struct antenna_setup new_ant;
|
int other_antenna;
|
|
int sample_current = rt2x00link_antenna_get_link_rssi(rt2x00dev);
|
int sample_other = rt2x00link_antenna_get_rssi_history(rt2x00dev);
|
|
memcpy(&new_ant, &ant->active, sizeof(new_ant));
|
|
/*
|
* We are done sampling. Now we should evaluate the results.
|
*/
|
ant->flags &= ~ANTENNA_MODE_SAMPLE;
|
|
/*
|
* During the last period we have sampled the RSSI
|
* from both antennas. It now is time to determine
|
* which antenna demonstrated the best performance.
|
* When we are already on the antenna with the best
|
* performance, just create a good starting point
|
* for the history and we are done.
|
*/
|
if (sample_current >= sample_other) {
|
rt2x00link_antenna_update_rssi_history(rt2x00dev,
|
sample_current);
|
return;
|
}
|
|
other_antenna = (ant->active.rx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;
|
|
if (ant->flags & ANTENNA_RX_DIVERSITY)
|
new_ant.rx = other_antenna;
|
|
if (ant->flags & ANTENNA_TX_DIVERSITY)
|
new_ant.tx = other_antenna;
|
|
rt2x00lib_config_antenna(rt2x00dev, new_ant);
|
}
|
|
static void rt2x00lib_antenna_diversity_eval(struct rt2x00_dev *rt2x00dev)
|
{
|
struct link_ant *ant = &rt2x00dev->link.ant;
|
struct antenna_setup new_ant;
|
int rssi_curr;
|
int rssi_old;
|
|
memcpy(&new_ant, &ant->active, sizeof(new_ant));
|
|
/*
|
* Get current RSSI value along with the historical value,
|
* after that update the history with the current value.
|
*/
|
rssi_curr = rt2x00link_antenna_get_link_rssi(rt2x00dev);
|
rssi_old = rt2x00link_antenna_get_rssi_history(rt2x00dev);
|
rt2x00link_antenna_update_rssi_history(rt2x00dev, rssi_curr);
|
|
/*
|
* Legacy driver indicates that we should swap antenna's
|
* when the difference in RSSI is greater that 5. This
|
* also should be done when the RSSI was actually better
|
* then the previous sample.
|
* When the difference exceeds the threshold we should
|
* sample the rssi from the other antenna to make a valid
|
* comparison between the 2 antennas.
|
*/
|
if (abs(rssi_curr - rssi_old) < 5)
|
return;
|
|
ant->flags |= ANTENNA_MODE_SAMPLE;
|
|
if (ant->flags & ANTENNA_RX_DIVERSITY)
|
new_ant.rx = (new_ant.rx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;
|
|
if (ant->flags & ANTENNA_TX_DIVERSITY)
|
new_ant.tx = (new_ant.tx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;
|
|
rt2x00lib_config_antenna(rt2x00dev, new_ant);
|
}
|
|
static bool rt2x00lib_antenna_diversity(struct rt2x00_dev *rt2x00dev)
|
{
|
struct link_ant *ant = &rt2x00dev->link.ant;
|
|
/*
|
* Determine if software diversity is enabled for
|
* either the TX or RX antenna (or both).
|
*/
|
if (!(ant->flags & ANTENNA_RX_DIVERSITY) &&
|
!(ant->flags & ANTENNA_TX_DIVERSITY)) {
|
ant->flags = 0;
|
return true;
|
}
|
|
/*
|
* If we have only sampled the data over the last period
|
* we should now harvest the data. Otherwise just evaluate
|
* the data. The latter should only be performed once
|
* every 2 seconds.
|
*/
|
if (ant->flags & ANTENNA_MODE_SAMPLE) {
|
rt2x00lib_antenna_diversity_sample(rt2x00dev);
|
return true;
|
} else if (rt2x00dev->link.count & 1) {
|
rt2x00lib_antenna_diversity_eval(rt2x00dev);
|
return true;
|
}
|
|
return false;
|
}
|
|
void rt2x00link_update_stats(struct rt2x00_dev *rt2x00dev,
|
struct sk_buff *skb,
|
struct rxdone_entry_desc *rxdesc)
|
{
|
struct link *link = &rt2x00dev->link;
|
struct link_qual *qual = &rt2x00dev->link.qual;
|
struct link_ant *ant = &rt2x00dev->link.ant;
|
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
|
|
/*
|
* No need to update the stats for !=STA interfaces
|
*/
|
if (!rt2x00dev->intf_sta_count)
|
return;
|
|
/*
|
* Frame was received successfully since non-succesfull
|
* frames would have been dropped by the hardware.
|
*/
|
qual->rx_success++;
|
|
/*
|
* We are only interested in quality statistics from
|
* beacons which came from the BSS which we are
|
* associated with.
|
*/
|
if (!ieee80211_is_beacon(hdr->frame_control) ||
|
!(rxdesc->dev_flags & RXDONE_MY_BSS))
|
return;
|
|
/*
|
* Update global RSSI
|
*/
|
ewma_rssi_add(&link->avg_rssi, -rxdesc->rssi);
|
|
/*
|
* Update antenna RSSI
|
*/
|
ewma_rssi_add(&ant->rssi_ant, -rxdesc->rssi);
|
}
|
|
void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev)
|
{
|
struct link *link = &rt2x00dev->link;
|
|
/*
|
* Single monitor mode interfaces should never have
|
* work with link tuners.
|
*/
|
if (!rt2x00dev->intf_ap_count && !rt2x00dev->intf_sta_count)
|
return;
|
|
/*
|
* While scanning, link tuning is disabled. By default
|
* the most sensitive settings will be used to make sure
|
* that all beacons and probe responses will be received
|
* during the scan.
|
*/
|
if (test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags))
|
return;
|
|
rt2x00link_reset_tuner(rt2x00dev, false);
|
|
if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
|
ieee80211_queue_delayed_work(rt2x00dev->hw,
|
&link->work, LINK_TUNE_INTERVAL);
|
}
|
|
void rt2x00link_stop_tuner(struct rt2x00_dev *rt2x00dev)
|
{
|
cancel_delayed_work_sync(&rt2x00dev->link.work);
|
}
|
|
void rt2x00link_reset_tuner(struct rt2x00_dev *rt2x00dev, bool antenna)
|
{
|
struct link_qual *qual = &rt2x00dev->link.qual;
|
u8 vgc_level = qual->vgc_level_reg;
|
|
if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
|
return;
|
|
/*
|
* Reset link information.
|
* Both the currently active vgc level as well as
|
* the link tuner counter should be reset. Resetting
|
* the counter is important for devices where the
|
* device should only perform link tuning during the
|
* first minute after being enabled.
|
*/
|
rt2x00dev->link.count = 0;
|
memset(qual, 0, sizeof(*qual));
|
ewma_rssi_init(&rt2x00dev->link.avg_rssi);
|
|
/*
|
* Restore the VGC level as stored in the registers,
|
* the driver can use this to determine if the register
|
* must be updated during reset or not.
|
*/
|
qual->vgc_level_reg = vgc_level;
|
|
/*
|
* Reset the link tuner.
|
*/
|
rt2x00dev->ops->lib->reset_tuner(rt2x00dev, qual);
|
|
if (antenna)
|
rt2x00link_antenna_reset(rt2x00dev);
|
}
|
|
static void rt2x00link_reset_qual(struct rt2x00_dev *rt2x00dev)
|
{
|
struct link_qual *qual = &rt2x00dev->link.qual;
|
|
qual->rx_success = 0;
|
qual->rx_failed = 0;
|
qual->tx_success = 0;
|
qual->tx_failed = 0;
|
}
|
|
static void rt2x00link_tuner_sta(struct rt2x00_dev *rt2x00dev, struct link *link)
|
{
|
struct link_qual *qual = &rt2x00dev->link.qual;
|
|
/*
|
* Update statistics.
|
*/
|
rt2x00dev->ops->lib->link_stats(rt2x00dev, qual);
|
rt2x00dev->low_level_stats.dot11FCSErrorCount += qual->rx_failed;
|
|
/*
|
* Update quality RSSI for link tuning,
|
* when we have received some frames and we managed to
|
* collect the RSSI data we could use this. Otherwise we
|
* must fallback to the default RSSI value.
|
*/
|
if (!qual->rx_success)
|
qual->rssi = DEFAULT_RSSI;
|
else
|
qual->rssi = rt2x00link_get_avg_rssi(&link->avg_rssi);
|
|
/*
|
* Check if link tuning is supported by the hardware, some hardware
|
* do not support link tuning at all, while other devices can disable
|
* the feature from the EEPROM.
|
*/
|
if (rt2x00_has_cap_link_tuning(rt2x00dev))
|
rt2x00dev->ops->lib->link_tuner(rt2x00dev, qual, link->count);
|
|
/*
|
* Send a signal to the led to update the led signal strength.
|
*/
|
rt2x00leds_led_quality(rt2x00dev, qual->rssi);
|
|
/*
|
* Evaluate antenna setup, make this the last step when
|
* rt2x00lib_antenna_diversity made changes the quality
|
* statistics will be reset.
|
*/
|
if (rt2x00lib_antenna_diversity(rt2x00dev))
|
rt2x00link_reset_qual(rt2x00dev);
|
}
|
|
static void rt2x00link_tuner(struct work_struct *work)
|
{
|
struct rt2x00_dev *rt2x00dev =
|
container_of(work, struct rt2x00_dev, link.work.work);
|
struct link *link = &rt2x00dev->link;
|
|
/*
|
* When the radio is shutting down we should
|
* immediately cease all link tuning.
|
*/
|
if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
|
test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags))
|
return;
|
|
/* Do not race with rt2x00mac_config(). */
|
mutex_lock(&rt2x00dev->conf_mutex);
|
|
if (rt2x00dev->intf_sta_count)
|
rt2x00link_tuner_sta(rt2x00dev, link);
|
|
if (rt2x00dev->ops->lib->gain_calibration &&
|
(link->count % (AGC_SECONDS / LINK_TUNE_SECONDS)) == 0)
|
rt2x00dev->ops->lib->gain_calibration(rt2x00dev);
|
|
if (rt2x00dev->ops->lib->vco_calibration &&
|
rt2x00_has_cap_vco_recalibration(rt2x00dev) &&
|
(link->count % (VCO_SECONDS / LINK_TUNE_SECONDS)) == 0)
|
rt2x00dev->ops->lib->vco_calibration(rt2x00dev);
|
|
mutex_unlock(&rt2x00dev->conf_mutex);
|
|
/*
|
* Increase tuner counter, and reschedule the next link tuner run.
|
*/
|
link->count++;
|
|
if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
|
ieee80211_queue_delayed_work(rt2x00dev->hw,
|
&link->work, LINK_TUNE_INTERVAL);
|
}
|
|
void rt2x00link_start_watchdog(struct rt2x00_dev *rt2x00dev)
|
{
|
struct link *link = &rt2x00dev->link;
|
|
if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
|
rt2x00dev->ops->lib->watchdog && !link->watchdog_disabled)
|
ieee80211_queue_delayed_work(rt2x00dev->hw,
|
&link->watchdog_work,
|
link->watchdog_interval);
|
}
|
|
void rt2x00link_stop_watchdog(struct rt2x00_dev *rt2x00dev)
|
{
|
cancel_delayed_work_sync(&rt2x00dev->link.watchdog_work);
|
}
|
|
static void rt2x00link_watchdog(struct work_struct *work)
|
{
|
struct rt2x00_dev *rt2x00dev =
|
container_of(work, struct rt2x00_dev, link.watchdog_work.work);
|
struct link *link = &rt2x00dev->link;
|
|
/*
|
* When the radio is shutting down we should
|
* immediately cease the watchdog monitoring.
|
*/
|
if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
|
return;
|
|
rt2x00dev->ops->lib->watchdog(rt2x00dev);
|
|
if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
|
ieee80211_queue_delayed_work(rt2x00dev->hw,
|
&link->watchdog_work,
|
link->watchdog_interval);
|
}
|
|
void rt2x00link_register(struct rt2x00_dev *rt2x00dev)
|
{
|
struct link *link = &rt2x00dev->link;
|
|
INIT_DELAYED_WORK(&link->work, rt2x00link_tuner);
|
INIT_DELAYED_WORK(&link->watchdog_work, rt2x00link_watchdog);
|
|
if (link->watchdog_interval == 0)
|
link->watchdog_interval = WATCHDOG_INTERVAL;
|
}
|
