Hello, everyone We looked at the beacon behavior [1] at the station side and we are trying to understand the logic used for computing the nexttbtt - Target Beacon Transmission Time - value [2]:
return (u32) tsf + divisor - offset; What's the reason for taking only 32 bits from TSF - which is 64 bits long - and losing the upper 32 bits? I noticed that the nexttbtt value is later used for arming the AR_NEXT_TBTT_TIMER [3] but there is no clear explanation related to this hardware timer. What is the connection between this hardware timer and TSF? My assumption is that, for triggering this timer, the value from the timer is continuously compared with the TSF value but I can't figure it out how a 32 bit value is compared with a 64 bit value. [1] http://lxr.free-electrons.com/source/drivers/net/wireless/ath/ath9k/common-beacon.c#L41 [2] http://lxr.free-electrons.com/source/drivers/net/wireless/ath/ath9k/common-beacon.c#L30 [3] http://lxr.free-electrons.com/source/drivers/net/wireless/ath/ath9k/hw.c?v=4.3#L2278 Thanks, Doru _______________________________________________ ath9k-devel mailing list ath9k-devel@lists.ath9k.org https://lists.ath9k.org/mailman/listinfo/ath9k-devel
