Re: [PATCH] tpm_tis: Issue a TPM2_Shutdown for TPM2 devices.

[Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>]

On Fri, May 05, 2017 at 03:39:01PM -0700, Josh Zimmerman wrote:

> I've seen some reference to the existing `suspend` method as being
> legacy. e.g., drivers/base/power/main.c:__device_suspend:

I think this is because class->pm is the modern way to do
class->suspend, not because class methods are legacy.

> In addition, it's not clear to me that the tpm codebase is using
> class->suspend right now; it looks like for the most part each
> device

Yes, but that doesn't mean this is the right way to do things, it just
means this old code hasn't really been updated. The tpm subsystem was
a total mess just a few years ago, not everything is cleaned up yet..

eg it would probably make much more sense to hook class->pm to do
tpm_pm_suspend rather than have each driver include the same
STATIC_DEV_PM_OPS.

> Is there some reason a similar approach of having each driver type
> register its own shutdown function pointer (that might just all be the
> same function, much like tpm_pm_suspend) would not be acceptable?

Now that we have so many tpm drivers it is a very good idea not to
introduce boilerplate into every driver, we should be going the other
way :)

Jason

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