Re: [tpmdd-devel] [PATCH] tpm: fix multiple race conditions in tpm_ppi.c

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Wed, Oct 22, 2014 at 01:05:33PM +0300, Jarkko Sakkinen wrote:
> On Tue, Oct 21, 2014 at 03:02:15PM -0600, Jason Gunthorpe wrote:
> > On Tue, Oct 21, 2014 at 11:42:51PM +0300, Jarkko Sakkinen wrote:
> > 
> > > > Personally, I'd sequence this commit right after your 'tpm: two-phase
> > > > chip management functions' commit because it makes it much saner (no
> > > > half step toward the new functions). I assume this is a theoretical
> > > > problem? Or do you have a two TPM system?
> > > 
> > > This has realized in Intel NUCs where there is PTT and dTPM module. Even
> > > when PTT is selected there is still ACPI device for dTPM so three is a
> > > race condition and PPI is unusable. I think that it's not good that code is
> > > not robust enough to deal with this.
> > 
> > Oh OK, you should probably explain in the commit log that this is a
> > bug fix that impacts real hardware, that qualifies it for the -stable
> > tree.
> > 
> > Assuming two-phase commit is nearly ready to go, I'd still sequence
> > this fix after two-phase for mainline and then use this patch as-is
> > for the 3.17 -stable backport of the mainline commit.
> 
> OK, makes sense. I'll try to get this done tonight.

I propose that the current fix would be actually taken into 3.18 as it
is and bigger changes would be introduced for 3.19 as the merge window
is closed. I do not think it would be wise at this point to make larger
structural changes.

I could however update the commit message and copyright platter
(should have 2012-2014, not just 2014). What do you think? Peter?

/Jarkko