Re: [PATCH v6 1/2] tpm: Issue a TPM2_Shutdown for TPM2 devices.

[Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

On Tue, Jun 20, 2017 at 12:21:22AM +0200, Jarkko Sakkinen wrote:
> On Tue, Jun 20, 2017 at 12:12:20AM +0200, Jarkko Sakkinen wrote:
> > On Mon, Jun 19, 2017 at 09:51:22AM -0600, Jason Gunthorpe wrote:
> > > On Mon, Jun 19, 2017 at 01:26:47AM +0200, Jarkko Sakkinen wrote:
> > >  
> > > > Feels weird that you have to call framework functions like that in the
> > > > driver. You must have brilliant reason to do so and that should be very
> > > > well documented in the code. This is terrible...
> > > 
> > > This was all discussed on the list. It the way these callbacks work,
> > > the higher levels in the callback stack call the lower levels, this
> > > allows each level the place the next level's callback properly, eg do
> > > things before/after as necessary.
> > > 
> > > Jason
> > 
> > I tried to look up for discussion from the patchwork. These had appeared
> > in v6. I guess I have to backtrack the discussions from my maidir
> > because I honestly don't understand why class shutdown would have to
> > call bus callback explicitly. There's nothing in the commit message
> > about this nor  is there any comment in the code.
> > 
> > This must be fairly recent development that I've missed?
> > 
> > /Jarkko
> 
> Found it:
> 
> "Looking at this closer, now you definately have to change the TPM
> patch to call through to the other shutdown methods. We can say
> current TPM drivers have no driver->shutdown, but we cannot be sure
> about the bus->shutdown, so may as well call both from tpm's
> class->shutdown.
> 
> I would say this should be done after the tpm2_shutdown completes as
> lower level shutdowns could remove register access.
> 
> Jason"
> 
> And makes sense.
> 
> This patch is a NAK for two reasons:
> 
> 1. No comment explaining this.
> 2. Patches are broken and they are in wrong order and cover letter is
>    missing
> 
> /Jarkko

I *tried* to apply them myself after sending this in order to be helpful
but they have compilation errors:

drivers/char/tpm/tpm-chip.c: In function ‘tpm_shutdown’:
drivers/char/tpm/tpm-chip.c:162:23: error: ‘TPM_SU_CLEAR’ undeclared (first use in this function)
   tpm2_shutdown(chip, TPM_SU_CLEAR);
                       ^~~~~~~~~~~~
drivers/char/tpm/tpm-chip.c:162:23: note: each undeclared identifier is reported only once for each function it appears in
drivers/char/tpm/tpm-chip.c: In function ‘tpm_chip_alloc’:
drivers/char/tpm/tpm-chip.c:214:17: error: ‘chip->dev.class’ is a pointer; did you mean to use ‘->’?
  chip->dev.class.shutdown = tpm_shutdown;

/Jarkko

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