The ath9k driver subtracts 3 dBm to the txpower as with two radios the signal power is doubled. The resulting value is assigned in an u16 which overflows and makes the card work at full power. Cc: stable@xxxxxxxxxx Signed-off-by: Matteo Croce <matteo@xxxxxxxxxxx> --- a/drivers/net/wireless/ath/ath9k/eeprom_def.c 2010-12-02 22:39:58.982020001 +0100 +++ b/drivers/net/wireless/ath/ath9k/eeprom_def.c 2010-12-03 00:36:23.637799002 +0100 @@ -1065,15 +1065,19 @@ case 1: break; case 2: - scaledPower -= REDUCE_SCALED_POWER_BY_TWO_CHAIN; + if (scaledPower > REDUCE_SCALED_POWER_BY_TWO_CHAIN) + scaledPower -= REDUCE_SCALED_POWER_BY_TWO_CHAIN; + else + scaledPower = 0; break; case 3: - scaledPower -= REDUCE_SCALED_POWER_BY_THREE_CHAIN; + if (scaledPower > REDUCE_SCALED_POWER_BY_THREE_CHAIN) + scaledPower -= REDUCE_SCALED_POWER_BY_THREE_CHAIN; + else + scaledPower = 0; break; } - scaledPower = max((u16)0, scaledPower); - if (IS_CHAN_2GHZ(chan)) { numCtlModes = ARRAY_SIZE(ctlModesFor11g) - SUB_NUM_CTL_MODES_AT_2G_40; -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html