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Date: Wed, 25 Oct 2017 14:17:44 -0600
From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
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Subject: Re: [PATCH v2] tpm: use struct tpm_chip for tpm_chip_find_get()
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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