diff options
Diffstat (limited to 'drivers/net/wireless/rt2x00/rt2x00link.c')
| -rw-r--r-- | drivers/net/wireless/rt2x00/rt2x00link.c | 145 |
1 files changed, 102 insertions, 43 deletions
diff --git a/drivers/net/wireless/rt2x00/rt2x00link.c b/drivers/net/wireless/rt2x00/rt2x00link.c index 0462d5ab6e9..ee08f1167f5 100644 --- a/drivers/net/wireless/rt2x00/rt2x00link.c +++ b/drivers/net/wireless/rt2x00/rt2x00link.c @@ -29,6 +29,71 @@ #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 + +/* + * When no TX/RX percentage could be calculated due to lack of + * frames on the air, we fallback to a percentage of 50%. + * This will assure we will get at least get some decent value + * when the link tuner starts. + * The value will be dropped and overwritten with the correct (measured) + * value anyway during the first run of the link tuner. + */ +#define DEFAULT_PERCENTAGE 50 + +/* + * Small helper macro to work with moving/walking averages. + * When adding a value to the average value the following calculation + * is needed: + * + * avg_rssi = ((avg_rssi * 7) + rssi) / 8; + * + * The advantage of this approach is that we only need 1 variable + * to store the average in (No need for a count and a total). + * But more importantly, normal average values will over time + * move less and less towards newly added values this results + * that with link tuning, the device can have a very good RSSI + * for a few minutes but when the device is moved away from the AP + * the average will not decrease fast enough to compensate. + * The walking average compensates this and will move towards + * the new values correctly allowing a effective link tuning. + */ +#define MOVING_AVERAGE(__avg, __val, __samples) \ + ( (((__avg) * ((__samples) - 1)) + (__val)) / (__samples) ) + +/* + * Small helper macro for percentage calculation + * This is a very simple macro with the only catch that it will + * produce a default value in case no total value was provided. + */ +#define PERCENTAGE(__value, __total) \ + ( (__total) ? (((__value) * 100) / (__total)) : (DEFAULT_PERCENTAGE) ) + +/* + * For calculating the Signal quality we have determined + * the total number of success and failed RX and TX frames. + * With the addition of the average RSSI value we can determine + * the link quality using the following algorithm: + * + * rssi_percentage = (avg_rssi * 100) / rssi_offset + * rx_percentage = (rx_success * 100) / rx_total + * tx_percentage = (tx_success * 100) / tx_total + * avg_signal = ((WEIGHT_RSSI * avg_rssi) + + * (WEIGHT_TX * tx_percentage) + + * (WEIGHT_RX * rx_percentage)) / 100 + * + * This value should then be checked to not be greater then 100. + * This means the values of WEIGHT_RSSI, WEIGHT_RX, WEIGHT_TX must + * sum up to 100 as well. + */ +#define WEIGHT_RSSI 20 +#define WEIGHT_RX 40 +#define WEIGHT_TX 40 + static int rt2x00link_antenna_get_link_rssi(struct rt2x00_dev *rt2x00dev) { struct link_ant *ant = &rt2x00dev->link.ant; @@ -191,6 +256,7 @@ 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; @@ -215,9 +281,9 @@ void rt2x00link_update_stats(struct rt2x00_dev *rt2x00dev, /* * Update global RSSI */ - if (qual->avg_rssi) - avg_rssi = MOVING_AVERAGE(qual->avg_rssi, rxdesc->rssi, 8); - qual->avg_rssi = avg_rssi; + if (link->avg_rssi) + avg_rssi = MOVING_AVERAGE(link->avg_rssi, rxdesc->rssi, 8); + link->avg_rssi = avg_rssi; /* * Update antenna RSSI @@ -229,21 +295,13 @@ void rt2x00link_update_stats(struct rt2x00_dev *rt2x00dev, static void rt2x00link_precalculate_signal(struct rt2x00_dev *rt2x00dev) { + struct link *link = &rt2x00dev->link; struct link_qual *qual = &rt2x00dev->link.qual; - if (qual->rx_failed || qual->rx_success) - qual->rx_percentage = - (qual->rx_success * 100) / - (qual->rx_failed + qual->rx_success); - else - qual->rx_percentage = 50; - - if (qual->tx_failed || qual->tx_success) - qual->tx_percentage = - (qual->tx_success * 100) / - (qual->tx_failed + qual->tx_success); - else - qual->tx_percentage = 50; + link->rx_percentage = + PERCENTAGE(qual->rx_success, qual->rx_failed + qual->rx_success); + link->tx_percentage = + PERCENTAGE(qual->tx_success, qual->tx_failed + qual->tx_success); qual->rx_success = 0; qual->rx_failed = 0; @@ -253,7 +311,7 @@ static void rt2x00link_precalculate_signal(struct rt2x00_dev *rt2x00dev) int rt2x00link_calculate_signal(struct rt2x00_dev *rt2x00dev, int rssi) { - struct link_qual *qual = &rt2x00dev->link.qual; + struct link *link = &rt2x00dev->link; int rssi_percentage = 0; int signal; @@ -267,22 +325,22 @@ int rt2x00link_calculate_signal(struct rt2x00_dev *rt2x00dev, int rssi) * Calculate the different percentages, * which will be used for the signal. */ - rssi_percentage = (rssi * 100) / rt2x00dev->rssi_offset; + rssi_percentage = PERCENTAGE(rssi, rt2x00dev->rssi_offset); /* * Add the individual percentages and use the WEIGHT * defines to calculate the current link signal. */ signal = ((WEIGHT_RSSI * rssi_percentage) + - (WEIGHT_TX * qual->tx_percentage) + - (WEIGHT_RX * qual->rx_percentage)) / 100; + (WEIGHT_TX * link->tx_percentage) + + (WEIGHT_RX * link->rx_percentage)) / 100; return max_t(int, signal, 100); } void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev) { - struct link_qual *qual = &rt2x00dev->link.qual; + struct link *link = &rt2x00dev->link; /* * Link tuning should only be performed when @@ -293,26 +351,13 @@ void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev) if (!rt2x00dev->intf_ap_count && !rt2x00dev->intf_sta_count) return; - /* - * Clear all (possibly) pre-existing quality statistics. - */ - memset(qual, 0, sizeof(*qual)); - - /* - * The RX and TX percentage should start at 50% - * this will assure we will get at least get some - * decent value when the link tuner starts. - * The value will be dropped and overwritten with - * the correct (measured) value anyway during the - * first run of the link tuner. - */ - qual->rx_percentage = 50; - qual->tx_percentage = 50; + link->rx_percentage = DEFAULT_PERCENTAGE; + link->tx_percentage = DEFAULT_PERCENTAGE; rt2x00link_reset_tuner(rt2x00dev, false); queue_delayed_work(rt2x00dev->hw->workqueue, - &rt2x00dev->link.work, LINK_TUNE_INTERVAL); + &link->work, LINK_TUNE_INTERVAL); } void rt2x00link_stop_tuner(struct rt2x00_dev *rt2x00dev) @@ -322,6 +367,8 @@ void rt2x00link_stop_tuner(struct rt2x00_dev *rt2x00dev) void rt2x00link_reset_tuner(struct rt2x00_dev *rt2x00dev, bool antenna) { + struct link_qual *qual = &rt2x00dev->link.qual; + if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) return; @@ -334,12 +381,12 @@ void rt2x00link_reset_tuner(struct rt2x00_dev *rt2x00dev, bool antenna) * first minute after being enabled. */ rt2x00dev->link.count = 0; - rt2x00dev->link.vgc_level = 0; + memset(qual, 0, sizeof(*qual)); /* * Reset the link tuner. */ - rt2x00dev->ops->lib->reset_tuner(rt2x00dev); + rt2x00dev->ops->lib->reset_tuner(rt2x00dev, qual); if (antenna) rt2x00link_antenna_reset(rt2x00dev); @@ -349,6 +396,7 @@ 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; struct link_qual *qual = &rt2x00dev->link.qual; /* @@ -365,11 +413,22 @@ static void rt2x00link_tuner(struct work_struct *work) 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 (!link->avg_rssi || !qual->rx_success) + qual->rssi = DEFAULT_RSSI; + else + qual->rssi = link->avg_rssi; + + /* * Only perform the link tuning when Link tuning * has been enabled (This could have been disabled from the EEPROM). */ if (!test_bit(CONFIG_DISABLE_LINK_TUNING, &rt2x00dev->flags)) - rt2x00dev->ops->lib->link_tuner(rt2x00dev); + rt2x00dev->ops->lib->link_tuner(rt2x00dev, qual, link->count); /* * Precalculate a portion of the link signal which is @@ -380,7 +439,7 @@ static void rt2x00link_tuner(struct work_struct *work) /* * Send a signal to the led to update the led signal strength. */ - rt2x00leds_led_quality(rt2x00dev, qual->avg_rssi); + rt2x00leds_led_quality(rt2x00dev, link->avg_rssi); /* * Evaluate antenna setup, make this the last step since this could @@ -391,9 +450,9 @@ static void rt2x00link_tuner(struct work_struct *work) /* * Increase tuner counter, and reschedule the next link tuner run. */ - rt2x00dev->link.count++; + link->count++; queue_delayed_work(rt2x00dev->hw->workqueue, - &rt2x00dev->link.work, LINK_TUNE_INTERVAL); + &link->work, LINK_TUNE_INTERVAL); } void rt2x00link_register(struct rt2x00_dev *rt2x00dev) |