Re: [PATCH] RDMA/siw: Add missing Kconfig selections

[Leon Romanovsky <leon@kernel.org>]

On Thu, Sep 01, 2022 at 09:25:39AM -0300, Jason Gunthorpe wrote:
> On Wed, Aug 31, 2022 at 12:30:48PM -0400, Tom Talpey wrote:
> > The SoftiWARP Kconfig is missing "select" for CRYPTO and CRYPTO_CRC32C.
> > 
> > In addition, it improperly "depends on" LIBCRC32C, this should be a
> > "select", similar to net/sctp and others. As a dependency, SIW fails
> > to appear in generic configurations.
> > 
> > Signed-off-by: Tom Talpey <tom@talpey.com>
> > ---
> >  drivers/infiniband/sw/siw/Kconfig | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/infiniband/sw/siw/Kconfig
> > b/drivers/infiniband/sw/siw/Kconfig
> > index 1b5105cbabae..81b70a3eeb87 100644
> > --- a/drivers/infiniband/sw/siw/Kconfig
> > +++ b/drivers/infiniband/sw/siw/Kconfig
> > @@ -1,7 +1,10 @@
> >  config RDMA_SIW
> >         tristate "Software RDMA over TCP/IP (iWARP) driver"
> > -       depends on INET && INFINIBAND && LIBCRC32C
> > +       depends on INET && INFINIBAND
> >         depends on INFINIBAND_VIRT_DMA
> > +       select LIBCRC32C
> > +       select CRYPTO
> > +       select CRYPTO_CRC32C
> 
> This is against the kconfig instructions Documentation/kbuild/kconfig-language.rst:
> 
>   Note:
>         select should be used with care. select will force
>         a symbol to a value without visiting the dependencies.
>         By abusing select you are able to select a symbol FOO even
>         if FOO depends on BAR that is not set.
>         In general use select only for non-visible symbols
>         (no prompts anywhere) and for symbols with no dependencies.
>         That will limit the usefulness but on the other hand avoid
>         the illegal configurations all over.
> 
> None of them meet that criteria even though other places do abuse
> select like this as well.
> 
> It looked fine to me the way it was, you are supposed to have to
> select libcrc32c manually to make siw appear, and it already brings in
> the other symbols.

He took his snippet from RXE.

Thanks

> 
> Jason