IFRS 15

As per ifrs 15 in step 2 identifying the separate performance obligation.
Kaplan Text Says that

Warranty, if given as assurance that product will function as intended, then accounted as per IAS 37 PROVISION. Means no transaction price(tp) will be allocated. The contract which contain laptop + warranty of 2 years will be 1 performance obligation. But provision for warranty will be required as per IAS 37.

But If customer has option to purchase the warranty separately then it will be separate performance obligation this means portion of transaction price will be allocated to it.
My doubt is if warranty qualifies and becomes a separate performance obligation then we will allocate the the transaction price to this service or not.
Will we recognize the provision in respect of the probable cost that may incur due to that warranty on basis of most likely cost or expected cost. As per ias 37. Or not. Please help for clearing my doubt.