Re: [PATCH v3] tpm_crb: request and relinquish locality 0

From: Jarkko Sakkinen
Date: Fri Mar 17 2017 - 16:39:26 EST


On Fri, Mar 17, 2017 at 11:11:16AM -0600, Jason Gunthorpe wrote:
> On Fri, Mar 17, 2017 at 10:00:41AM -0700, Jerry Snitselaar wrote:
>
> > > Changing the return value to -EBUSY was a stupid mistake from my side.
> > >
> > > I'll try revise this a bit in a way that the API will allow positive
> > > value for stating that the given locality has been already taking.
> >
> > Is there a big performance hit with requesting and releasing locality?
> > If instead it just released it when release_locality is called I think
> > the changes are pretty minor.
>
> If you can measure please let us know :)
>
> This is all very old it may not actually make any sense..
>
> .. and as I said earlier if we want to 'cache' the locality for
> performance then the core code should do it.
>
> I kinda thought the point of releasing the locality was to allow other
> platform things to access the TPM, so I'm confused why TIS wouldn't
> always release it as well..
>
> Jason

I would propose to make tpm_tis_core to work like that.

/Jarkko