PKA fails after pairing and lock

[DS.4]

This is a follow up to this post:

https://community.st.com/t5/stm32-mcus-wireless/conflict-betwenn-pka-and-ble-after-pairing/m-p/76599?search-action-id=65799734948&search-result-uid=76599

So if I understand correctly , 

After CPU2 BLE stack finished working with the PKA, it turns it off, so to enable it we should : 

// Re-enable PKA if disabled
if ((PKA->CR & PKA_CR_EN) == 0) {
 PKA->CR |= PKA_CR_EN;
}

 

My question is how to Lock it or check its not currently Locked? I want to prevent any issues or races with BLE stack?