Hi Felix, Thank you for the comments. > On 2012-04-14 10:01 PM, Gabor Juhos wrote: >> The REDUCE_SCALED_POWER_BY_THREE_CHAIN symbol is >> defined in different eeprom files, and the value >> varies between the different files. >> >> In eeprom_def.c and in ar9003_eeprom.c the value >> of the symbol is 9, however the comments in these >> files indicates the value should be 10*log10(3)*2 >> which is 9.54242509439325. Replace the the value >> to 10 in these files. >> >> Also add comments to eeprom_9287.c. >> >> Signed-off-by: Gabor Juhos <juhosg@xxxxxxxxxxx> > I think we should keep the value 9. > If I understand the logic behind the power increase through chain > combining properly, this value only describes the worst-case (wrt. > regulatory compliance) upper limit of tx power, whereas in practice the > measured combined power output will be much lower than that due to > signal/phase differences. > Regulatory compliance is already properly tested on all devices with the > truncated value 9, so I don't think that we need to be even more > conservative and round up here. Ok, I will rework the patch. Apart from the inconsistency between the REDUCE_SCALED_POWER_BY_THREE_CHAIN values, there is another thing which confuses me. In the 'ath9k_hw_set_*_power_cal_table' functions the driver uses the REDUCE_SCALED_POWER_BY_THREE_CHAIN constant to reduce the power values. In the 'ath9k_hw_update_regulatory_maxpower' function it uses the INCREASE_MAXPOW_BY_THREE_CHAIN constant to compensate the reduction. However the two constants are different. I might be wrong, but in my opinion the driver should use the same constant in both functions. -Gabor -- 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
