diff options
Diffstat (limited to 'drivers/net/wireless/rt2x00/rt2800lib.c')
| -rw-r--r-- | drivers/net/wireless/rt2x00/rt2800lib.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c index 3e059b6..3bc206d 100644 --- a/drivers/net/wireless/rt2x00/rt2800lib.c +++ b/drivers/net/wireless/rt2x00/rt2800lib.c @@ -2586,6 +2586,15 @@ static u8 rt2800_compensate_txpower(struct rt2x00_dev *rt2x00dev, int is_rate_b, return min_t(u8, txpower, 0xc); } +/* + * We configure transmit power using MAC TX_PWR_CFG_{0,...,N} registers and + * BBP R1 register. TX_PWR_CFG_X allow to configure per rate TX power values, + * 4 bits for each rate (tune from 0 to 15 dBm). BBP_R1 controls transmit power + * for all rates, but allow to set only 4 discrete values: -12, -6, 0 and 6 dBm. + * Reference per rate transmit power values are located in the EEPROM at + * EEPROM_TXPOWER_BYRATE offset. We adjust them and BBP R1 settings according to + * current conditions (i.e. band, bandwidth, temperature, user settings). + */ static void rt2800_config_txpower(struct rt2x00_dev *rt2x00dev, struct ieee80211_channel *chan, int power_level) @@ -2597,17 +2606,24 @@ static void rt2800_config_txpower(struct rt2x00_dev *rt2x00dev, enum ieee80211_band band = chan->band; /* - * Calculate HT40 compensation delta + * Calculate HT40 compensation. For 40MHz we need to add or subtract + * value read from EEPROM (different for 2GHz and for 5GHz). */ delta = rt2800_get_txpower_bw_comp(rt2x00dev, band); /* - * calculate temperature compensation delta + * Calculate temperature compensation. Depends on measurement of current + * TSSI (Transmitter Signal Strength Indication) we know TX power (due + * to temperature or maybe other factors) is smaller or bigger than + * expected. We adjust it, based on TSSI reference and boundaries values + * provided in EEPROM. */ delta += rt2800_get_gain_calibration_delta(rt2x00dev); /* - * Apply regulatory delta. + * Decrease power according to user settings, on devices with unknown + * maximum tx power. For other devices we take user power_level into + * consideration on rt2800_compensate_txpower(). */ delta += rt2800_get_txpower_reg_delta(rt2x00dev, power_level, chan->max_power); |