Why is a point-to-volatile pointer, like “volatile int * p”, useful?

Question

volatile is to tell the compiler not to optimize the reference, so that every read/write does not use the value stored in register but does a real memory access

Answer 1

This code volatile int *p = some_addr declares a pointer to a volatile int. The pointer itself is not volatile.

In the unlikely event that you needed the pointer to be volatile as well as the int, you would need to use:

volatile int * volatile p;

I can't think of a situation where you would need to use that.