why use 'raw_spin_lock_irqsave' inf function 'of_find_node_with_property'

Hi, all
In function "of_find_node_with_property", why use "raw_spin_lock_irqsave" to disable preemption and disable interrupt?
If enable them, what impact will be observed?
This function just finds the node from the DTS file, it can't be interrupted or preempted?

I have done one test: remove "raw_spin_lock_irqsave" and "raw_spin_unlock_irqrestore" from this function,
It seems there is no any bad result, the Linux kernel still work well.

Best Regards
Jerry Huang