some missreading 1-wire BBB & ubutntu

I’ve some missreading on 1wire bus, seems timing problem
If I left enabled loadcpufreq & cpufrequtils I’ve about 500 missreading over 24 hour with sampling every 20s with those disabled I’m around 200 errors/24h.
I’m very newby with BBB but for what I’ve understood the w1.dts driver is just a mux mapping, it’s correct?
If yes where are handled the timing?

The 1w device is ds18b20, tested with:
direct GPIO connection with 2,2k & 4.7k pull up 3.3v power
GPIO connection with dual fet level shifter-amplifier 2,2k 4,7k 10k pull up 5v power
direct GPIO connection 4.7k parasitic power

I shall try soon the test with armstrong distro

about 3 hours that running on Amstrong without one missreading

With angstrom about 24 hours of sampling and just 8 missreading, nothing copared to the 200 on ubuntu, but anyway why missireading? Interrupts problem?