On 22 May 2015 at 19:11, Srinivasa Duvvuri <sduvvuri@xxxxxxxxxx> wrote: > Michal, > Sorry I was out sick last few days. Thanks for splitting and creating 2 > patches. > The math for total cycle counts makes sense but the math to handle the > rx_clear_count > does not seem right to me. For the total cycle count we know that the > count changes > from 0xffffffff to 0x7fffffff. So, we clearly know the wrap around point > . But for > rcc( rx_clear_count) we do not know when this count is halfed (wrapped). > > Lets say rcc_prev is the previous clear cycle count, rcc is the current > clear cycle count > and rcc_wrap is a point at which the the total cycle count is wrapped > from 0xfffffffff to 0x7fffffff . > At that point the rcc_wrap resets to rcc_wrap/2. > > Here is how counts wrap around. > > cc_prev ............0xffffffff -> 0x7fffffff ................ cc > rcc_prev ............rcc_wrap -> rcc_wrap/2 ........... rcc. > > The right math to calculate rcc_delta would be (rcc_wrap - rcc_prev) + > (rcc - rcc_wrap/2). > To do the math, we need the rcc_wrap which we do not have. > the patch seems to simply do 2*rcc - rcc_prev . Unless I am missing > something, > this does not seem right to me. Ah, you're right. I guess I'll need to discard the data like you originally did upon wraparound detection. Michał -- 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
