Re: [PATCH] tpm: Move Linux RNG connection to hwrng

[Jason Gunthorpe]

On Wed, Oct 25, 2017 at 08:58:17PM +0200, Jarkko Sakkinen wrote:
> On Wed, Oct 25, 2017 at 08:15:09PM +0530, PrasannaKumar Muralidharan wrote:
> > > +       if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM))
> > > +               return 0;
> > 
> > Can #ifndef CONFIG_HW_RANDOM_TPM be used instead? That way an if
> > condition can be avoided.
> 
> Nope. There is no reason to avoid the if-condition. Compiler will take
> care of it. IS_ENABLED() macro is available just for the purpose Jason
> is using it.
> 
> > > +       char tpm_hwrng_name[64];
> > > +       struct hwrng tpm_hwrng;
> > > +
> > 
> > Can this also be put inside the #ifdef?
> 
> Yes. It should be inside #ifdef.

Then we need #idefs in the .c code, IS_ENABLED is not enough :\ I
don't think the few bytes matters enough to bother.

Jason