Unable to resume after suspend/wfi state

Hi,     I am trying to understand  the Linux Power management Unit framework. I have an ARM Cortex-A9x4 board. When I enable pm_test or pass initcall_debug parameter through U-boot via bootargs the system goes into (wfi/suspend state) and resumes properly.However, the issue is when I disable pm_test and initcall_debug and put my system into WFI/SUSPEND state , it does not resume even if the registered wakeup IRQ is generated.     I am using linux kernel source revision 4.4.16. Can somebody please help me regarding this issue? Regards,Amit.