kernel 4.x reboot command not working

Hello,
I did a kernel update for my BBB Angstrom system. everything is working fine except when i write “reboot” command. it turns off and doesn’t boot up again unless i unplugged/replugged the power source manually.
This thing happens with kernel 4.1 /4.4.12 /4.4.16 i didn’t tested any other kernels from 4.x

can any one guide me to fix this bug?

the kernels I worked on before where 3.8 and 3.14. 3.8 the reboot was working fine with them

Tamer

I would get out of Angstrom and move to Debian, if you want to use kernel 4.x.
I know that reboot works with kernel 4 on Debian.

— Graham