RE: [tpmdd-devel] [PATCH] Add "shutdown" to "struct class".

From: Winkler, Tomas
Date: Mon May 15 2017 - 12:17:51 EST


>
> On Sat, May 13, 2017 at 12:43:11PM +0000, Winkler, Tomas wrote:
> > > The TPM class has some common shutdown code that must be executed
> > > for all drivers. This adds some needed functionality for that
> >
> > The issue with this is, that on some platforms the only storage can be
> > eMMC and TPM is using it,. It has to be ensured that the storage
> > device won't go down before TPM2_shutdown is called. And there is no
> > direct device hierarchy to ensure an orderly shutdown.
>
> Something will have to use the new device links stuff to define that
> dependency, but that seems unrelated to this patch?


Yep, it's not directly related to this specific patch, this is more relevant particularly to TPM2_shutdown.

> Can the kernel really shut down the eMMC while the hidden platform stuff is
> still possibly using it? Goofy..

eMMC is single headed, so yes that can happen.

Tomas