I was carefully examining the thread "HAL CPU Overhead " trying to find the
purpose of call, ath_hal_gettsf64(ah).
According to spec. of ieee80211 standard (sec. 11.1) TSF timer is an integer
counter of 64 bit which will increment in every microsecond,
should be used for calculating timestamp, TBTT in beacon frame.
specially it is very necessary in maste rmode, ad-hoc 80211 synchronization.
ath_hal_gettsf64(ah) function is called 5 times in if_ath.c file to get tsf
1325(ln#) tsf = ath_hal_gettsf64(ah); - this tsf value is passed to function
4062 tsf = ath_hal_gettsf64(ah); -this tsf timer value is using to
calculate tsf TU and slot
4358 tsf = ath_hal_gettsf64(ah) - this tsf value is using to calculate
5267 tsf = ath_hal_gettsf64(ah);
7420 tsf = ath_hal_gettsf64(ah);
Herb found, it consumed lots of CPU time and also told that, he put tsf = 0
statically and still it was working well in even when node is working as AP,
My question is:
How it is possible ???
So what is the functionality of tsf value?
is it giving clock time value in microsecond?
If any HAL developer help this out, that would be appreciated. I want to work in
optimization in HAL overhead.