On Wed, Oct 25, 2017 at 10:07:46PM +0200, Jarkko Sakkinen wrote: > The id has a nice feature that it is unique for one boot cycle you can > even try to get a chip that has been deleted. It has the most stable > properties in the long run. It isn't unique, we can re-use ids them via idr_alloc(). We should never use index inside the kernel. > Address is a reusable identifier in one boot cycle. It is invalid to pass in a chip for which the caller does not hold a kref, so address is the safest argument. Jason