On Wed September 15 2010 08:07:36 Jonathan Guerin wrote: > I'm capturing using a third-party station. I've had to use a Madwifi > station, as ath5k throws a lot of spurious timestamps up, which make > calculating this very, very difficult. ah, that's interesting and something we should check, too... > Actually, I've found that they were exactly one slot time negative > (give or take 1us). That said, I was doing these calculations using > the 802.11a OFDM spec timings. I looked at the driver and realised > that SIFS is actually being initialised to 14us, whereas it should be > set to 16us. This will also affect DIFS. Once I take these into > consideration, they come up as approximately 4-5us out. Now that I > think about it, it could make sense. hmm, we have a function ath5k_hw_get_default_sifs() which returns 16 for 802.11a, but it's not used for setting the IFS... also i think current ath5k_hw_reset_tx_queue() is buggy and sets the AIFS wrongly. it uses ah->ah_aifs + tq->tqi_aifs which is 2 + AR5K_TXQ_USEDEFAULT which results in 2 + (-1). that does not make sense to me and i will post a patch fixing up some of that confusion (but not the SIFS issue) today. bruno -- 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
