On Thu, May 13, 2021 at 05:20:06PM +0200, Paolo Bonzini wrote:
> On 12/05/21 09:02, David Gibson wrote:
> > > But with "imply" you could end up with a PSERIES that does not have NVDIMM
> > > when also using --without-default-devices, couldn't you? Why don't you use
> > > "select" instead of "imply" ?
> > Oh.. clearly I misunderstand the semantics of "imply".  If we don't
> > need NVDIMM for PSERIES, why does there need to be any Kconfig
> > connection between them at all?
> 
> Because you still want it in the binary by default (i.e. unless
> --without-default-devices).
> 
> Basically,
> 
> config PSERIES
>     imply NVDIMM
> 
> is the same as
> 
> config NVDIMM
>     default y if PSERIES

Ah, ok, I get it now.  "imply" is a terrible word for this, but ok.

> Both of them are a way to say "PSERIES can work with NVDIMM so you want to
> include it unless you want some fine tuning".  In Linux "imply" is very
> rarely used, while in QEMU it's quite common because it keeps the many
> per-board defaults close together.
> 
> Paolo
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson