RL-ARM: Low Power RTX Applications on Cortex-M Devices

Hi,
i read http://www.keil.com/support/docs/3591.htm
but workarond case B not resolve problem
WFI never exit if interrupt occured between if (Suspend) {
and WFI
I can't find any info about enable IRQ on WFI instruction (it's absolutly logically)
I see arm.com but no info.

May be you knows more ?

Thanks in advance
Mitek