Hi Dan, Thank you for the comments. > (Failed to reply-all originally, sorry:) > > Erm... > > On Sat, Apr 14, 2012 at 1:01 PM, Gabor Juhos <juhosg@xxxxxxxxxxx> wrote: >> >> 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. > > So the truncated constant is off by a quarter-dB for 9 or for 10. Do > the chips care one way or the other? (For comparison, Intel uses 4.5 > dB, i.e. 9 in this notation, to mean "divide-by-3". That's what ath9k > has now). In my understanding the value is not related to the chip. It is used for per-chain tx power reduction, in order to ensure regulatory compliance. Using 10 instead of 9 means that the overall tx power will be lower. > Are you making it consistent with some other file that's not mentioned > here? If not, why? I'm tyring to make it consistent between ar9003_eeprom.c, eeprom_def.c and eeprom_9287.c. The first two files uses 9, whereas eeprom_9287 uses 10. Considering Felix's comment, I will update the patch and will use 9 instead of 10. Although that will replace the value in eeprom_9287.c, but that should not cause problems, because the AR9287 does not supports 3x3. >> #define REDUCE_SCALED_POWER_BY_TWO_CHAIN 6 /* 10*log10(2)*2 */ >> -#define REDUCE_SCALED_POWER_BY_THREE_CHAIN 9 /* 10*log10(3)*2 */ >> +#define REDUCE_SCALED_POWER_BY_THREE_CHAIN 10 /* 10*log10(3)*2 */ >> #define PWRINCR_3_TO_1_CHAIN 9 /* 10*log(3)*2 */ > > Why only change one of two 9s to a 10? Why not also PWRINCR_3_TO_1_CHAIN? The PWRINCR_* symbols are not used anywhere and should be removed. -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
