Re: [RFC PATCH 1/5] hw/mem/nvdimm: Use Kconfig 'imply' instead of 'depends on'

[David Gibson <david@gibson.dropbear.id.au>]

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On Wed, May 12, 2021 at 06:53:22AM +0200, Thomas Huth wrote:
> On 12/05/2021 05.57, Philippe Mathieu-Daudé wrote:
> > On 5/12/21 4:24 AM, David Gibson wrote:
> > > On Tue, May 11, 2021 at 05:53:50PM +0200, Philippe Mathieu-Daudé wrote:
> > > > Per the kconfig.rst:
> > > > 
> > > >    A device should be listed [...] ``imply`` if (depending on
> > > >    the QEMU command line) the board may or  may not be started
> > > >    without it.
> > > > 
> > > > This is the case with the NVDIMM device, so use the 'imply'
> > > > weak reverse dependency to select the symbol.
> > > 
> > > Uh.. It should definitely be possible to start a pseries machine
> > > without NVDIMM.  I would have guessed the same for PC.
> > 
> > Yes, this is what this patch does. With it we can build with:
> > CONFIG_NVDIMM=n
> 
> 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?

-- 
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

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